id
stringlengths 24
24
| doi
stringlengths 28
32
| title
stringlengths 8
495
| abstract
stringlengths 17
5.7k
| authors
stringlengths 5
2.65k
| categories
stringlengths 4
700
| license
stringclasses 3
values | origin
stringclasses 1
value | date
stringdate 1970-01-01 00:00:00
2025-03-24 00:00:00
| url
stringlengths 119
367
⌀ |
|---|---|---|---|---|---|---|---|---|---|
60c7505abdbb893367a39f02 | 10.26434/chemrxiv.13022606.v1 | Reversibility in a Plastically Flexible Coordination Polymer Crystal: A High-Pressure Study | <p>Single crystals which
exhibit mechanical flexibility are promising materials for advanced
technological applications. Before such materials can be used, detailed
understanding of the mechanisms and structural effects of bending are needed.
Coordination polymer single crystal represent a fascinating class of
mechanically flexible material; their bending contradicts existing models.
Using single crystal X-ray diffraction and microfocus Raman spectroscopy, we
study in atomic detail the high-pressure response of the plastically flexible coordination polymer [Zn(μ‐Cl)<sub>2</sub>(3,5‐dichloropyridine)<sub>2</sub>]<i><sub>n</sub>.</i> In stark contrast to three-point bending, the
quasi-hydrostatic compression of the single crystal is completely reversible,
even following compression to over 9 GPa. A structural phase transition is
observed at <i>ca. </i>5 GPa. <i>Ab initio</i> DFT calculations show this
transition to result from the pressure-induced softening of low frequency
vibrations. This phase transition is not observed during three-point bending.
Our combined experimental and theoretical high-pressure investigation propose
slight compression at low levels of bending. However, our studies provide the
first indication of overall disparate mechanical responses of bulk flexibility
and quasi-hydrostatic compression. We suspect this to be a general feature of
mechanically plastic materials. <b></b></p> | Xiaojiao Liu; Adam Michalchuk; Biswajit Bhattacharya; Franziska Emmerling; Colin R. Pulham | Spectroscopy (Physical Chem.); Structure; Crystallography | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7505abdbb893367a39f02/original/reversibility-in-a-plastically-flexible-coordination-polymer-crystal-a-high-pressure-study.pdf |
65f98f7f66c13817295197ff | 10.26434/chemrxiv-2024-5ffk1 | Cu infiltrated Ni-YSZ cathode in CO2 (+H2) stream: Reverse Water Gas Shift vs. CO2 electrolysis | Ni-YSZ electrode is known to perform in CO2 (+H2) stream. Introducing H2 in CO2 containing streams enables thermochemical reverse water gas shift reaction (CO2 + H2 CO + H2O rWGS) at OCV. Without the application of any bias, the rWGS responds positively to an increase in temperature and concentrations of CO2 and H2. Application of bias results in enhancement in CO yield above the rWGS baseline value. With bias, both CO2 and H2O electrolysis are enabled. The infiltration of Cu on the Ni-YSZ backbone was found to significantly improve the reaction kinetics and increase H2 and CO production. Impedance analysis indicates that the kinetic limitation originates from reaction steps with slower time constants with Ni{Cu}x-YSZ outperforming Ni-YSZ in this aspect. Cu infiltration was found to suppress particle coarsening, which is typically observed on Ni-YSZ. | Vipin Kamboj; Chinmoy Ranjan | Catalysis; Energy; Electrocatalysis; Fuels - Energy Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-03-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65f98f7f66c13817295197ff/original/cu-infiltrated-ni-ysz-cathode-in-co2-h2-stream-reverse-water-gas-shift-vs-co2-electrolysis.pdf |
62fc9063e1594bb16ad323a3 | 10.26434/chemrxiv-2022-kxr24-v2 | A green and scalable electrochemical route for cost-effective mass production of MXenes | One of the most unique properties of two-dimensional carbides and nitrides of transition metals (MXenes) is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-scale application is limited by their costly chemical synthesis methods. In this work, the niche feature of MXene was capitalized in the packed-bed electrochemical reactor (PBER) to produce MXene at an unprecedented reaction rate and yield with minimal chemical waste. A simple NH4F solution was employed as the green electrolyte which could be used repeatedly without any loss in its efficacy. Surprisingly, both fluoride and ammonium were found to play critical roles in the electrochemical etching, functionalization, and expansion of the layered parent materials (MAXs) through which the liberation of ammonia gas was observed. The electrochemically produced MXenes (eMXenes) with excellent conductivity, applied as supercapacitor electrodes, could deliver an ultra-high volumetric capacity (1408 F cm-3) and volumetric energy density (75.8 Wh L-1). This revolutionary green, energy efficient and scalable electrochemical route will not only pave the way for industrial-scale production of MXene but also open up a myriad of versatile electrochemical modifications for improved functional MXenes. | Zimo Huang; Jiadong Qin; Yuxuan Zhu; Kelin He; Hao Chen; Hui Ying Hoh; Munkhbayar Batmunkh; Tania Benedetti; Qitao Zhang; Chenliang Su; Shanqing Zhang; Yu Lin Zhong | Physical Chemistry; Materials Science; Chemical Engineering and Industrial Chemistry; Materials Processing; Nanostructured Materials - Materials; Electrochemistry - Mechanisms, Theory & Study | CC BY NC ND 4.0 | CHEMRXIV | 2022-08-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62fc9063e1594bb16ad323a3/original/a-green-and-scalable-electrochemical-route-for-cost-effective-mass-production-of-m-xenes.pdf |
653b218f48dad231207208dc | 10.26434/chemrxiv-2023-j55nv | Hydrogen-bonded frameworks containing aliphatic 3D linkers show high-capacity water vapour sorption | Hydrogen bonded frameworks were prepared from a tetra-amidinium component and three-dimensional cubane and bicyclopentane dicarboxylate linkers. Despite the incorporation of aliphatic components, the frameworks demonstrate strong and reversible uptake of water vapour, with one of the frameworks showing water uptake at very low relative humidity. | Phonlakrit Muang-Non; Carmen Zhou; Lauren Macreadie; Nicholas White | Organic Chemistry; Inorganic Chemistry; Supramolecular Chemistry (Org.); Supramolecular Chemistry (Inorg.); Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-10-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/653b218f48dad231207208dc/original/hydrogen-bonded-frameworks-containing-aliphatic-3d-linkers-show-high-capacity-water-vapour-sorption.pdf |
60c752a0337d6c17a5e28748 | 10.26434/chemrxiv.13331204.v1 | Electrochemical Reduction of CO2 to Ethylene with 32% Lower Energy at 80% Lower Cost via Coproduction of Glycolic Acid | <p>We are in a race against time to implement technologies for carbon
capture, conversion, and utilization (CCU) to create a closed anthropogenic
carbon cycle. Renewable energy powered electrochemical CO<sub>2</sub> reduction
(eCO<sub>2</sub>R) to fuels and chemicals is an attractive technology in this
context. Here, we demonstrate a strategy to drive economic feasibility of eCO<sub>2</sub>R
to ethylene (C<sub>2</sub>H<sub>4</sub>), the largest produced organic chemical,
by coupling with glycerol oxidation on anode. Our gold nano-dendrite anode
catalyst demonstrated very high activity (J ~377 mA/cm<sup>2</sup> at 1.2 V vs reversible
hydrogen electrode) and selectivity (~50% to glycolic acid (GA)) for glycerol
oxidation. The co-electrolysis process demonstrated record high selectivity of
~60% for C<sub>2</sub>H<sub>4</sub> production at a very low cell voltage of ~
1.7 V, translating to 32% reduction in required energy compared to conventional
eCO<sub>2</sub>R with water oxidation reaction on anode. The experimental
results were complemented with a detailed technoeconomic analysis that
indicated economic feasibility will depend on several factors such as price of
organic feed, selectivity of anode electrode, market value of chemicals
produced and most importantly cost of separation and purification. Our results
indicate that C<sub>2</sub>H<sub>4</sub> produced via conventional eCO<sub>2</sub>R would require electricity price to
plummet to <1 cents/kWh to be cost-competitive, while a co-electrolysis process to produce C<sub>2</sub>H<sub>4</sub>
and GA will help reduce C<sub>2</sub>H<sub>4 </sub>production cost by ~ 80% to
~1.08 $/kg, reaching
cost parity at electricity price of 5 cents/kWh. This study may trigger research
efforts for design of electrochemical processes with low electricity
requirement using cheap industrial waste streams. </p> | Mohd Adnan Khan; Shariful Nabil; Tareq A. Al-Attas; Soumyabrata Roy; M.M. Rahman; Steve Larter; Pulickel
M. Ajayan; Jinhuang Hu; Md Kibria | Electrocatalysis; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-12-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c752a0337d6c17a5e28748/original/electrochemical-reduction-of-co2-to-ethylene-with-32-lower-energy-at-80-lower-cost-via-coproduction-of-glycolic-acid.pdf |
60c73f1b567dfe79d3ec3920 | 10.26434/chemrxiv.7241036.v1 | Understanding the Effects of Sample Preparation on the Chemical Structures of Petroleum Imaged with Non-contact Atomic Force Microscopy | This study addresses the effect of sample preparation
conditions on the structural integrity and composition of heavy hydrocarbon
mixtures imaged by non-contact atomic force microscopy (nc-AFM). We designed
and prepared a set of organic molecules mimicking well-accepted key
characteristics of heavy oil asphaltenes including molecular architecture, molecular
weight, boiling point, atomic H/C ratio and bond strength. We deliberately
focused on multi-core molecule structures with long aliphatic linkers as this
architecture was largely absent in previous nc-AFM studies of petroleum
samples. The results confirm that all these molecules can be successfully imaged
and remain intact under the same preparation conditions. Moreover, comparison
with ultra-high resolution FT ICR-MS of a steam-cracked tar asphaltene sample
suggests that the single molecules identified by nc-AFM span the entire
molecule spectrum of the bulk sample. Overall, these results suggest that
petroleum molecules within the scope of chosen molecules studied herein can be
prepared intact and without bias and the imaged data can be representative. | Yunlong Zhang; Bruno Schuler; Shadi Fatayer; Leo Gross; Michael R. Harper; J. Douglas Kushnerick | Physical and Chemical Properties; Structure | CC BY NC ND 4.0 | CHEMRXIV | 2018-10-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73f1b567dfe79d3ec3920/original/understanding-the-effects-of-sample-preparation-on-the-chemical-structures-of-petroleum-imaged-with-non-contact-atomic-force-microscopy.pdf |
64e8c53ddd1a73847f822f76 | 10.26434/chemrxiv-2023-c9kfd | A Method to Selectively Determine Concentrations of Macromolecular Complexes: Overhauser-DNP Spectroscopy | Dynamic nuclear polarization (DNP) is a process achieved by transferring the spin polarization from an unpaired electron to the half-spin nuclei in a substance of interest through microwave irradiation, effectively enhancing the nuclear magnetic resonance (NMR) signals of the substance. The polarization mechanism involved in Overhauser-DNP allows the process to be carried out in ambient conditions, thus facilitating its technological implementation. Here we show a method to quantify protein complexes in solution by exploiting the correlation among the concentration, the enhancement of the solvent NMR signals, the unpaired electrons’ motions, and the microwave irradiation frequency. As a proof of concept, we quantify the proteins avidin and C-reactive protein by means of adequate paramagnetic molecular probes (i.e., ligands), and we show that the method allows to estimate the dissociation constant for the C-reactive protein complex. Furthermore, we provide a full structural characterization of the avidin complex by X-ray crystallography (XRD) and cryogenic electron microscopy (cryo-EM). | Jonas Milani; Felipe Saenz; Kelvin Lau; Florence Pojer; Sergey Nazarov ; Bertrand Dominique Beckert ; Alexander Myasnikov; Christophe Roussel; Holger Frauenrathe; Jean-Philippe Ansermet | Analytical Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64e8c53ddd1a73847f822f76/original/a-method-to-selectively-determine-concentrations-of-macromolecular-complexes-overhauser-dnp-spectroscopy.pdf |
65cf6c5be9ebbb4db98132d1 | 10.26434/chemrxiv-2024-wdw5g | Electromigrated gold nanogap tunnel junction arrays: Fabrication and electrical behavior in liquid and gaseous media | Tunnel junctions have been suggested as high-throughput electronic single molecule sensors in liquids, with several seminal experiments conducted using break junctions with reconfigurable gaps. For practical single molecule sensing applications, arrays of on-chip integrated fixed-gap tunnel junctions that can be built into compact systems are preferable. Fabricating nanogaps by electromigration is one of the most promising approaches to realize on-chip integrated tunnel junction sensors. However, the electrical behavior of fixed-gap tunnel junctions immersed in liquid media has not been systematically studied to date, and the formation of electromigrated nanogap tunnel junctions in liquid media has not yet been demonstrated. In this work, we perform a comparative study of the formation and electrical behavior of arrays of gold nanogap tunnel junctions made by feedback-controlled electromigration immersed in various liquid and gaseous media (deionized water, mesitylene, ethanol, nitrogen, and air). We demonstrate that tunnel junctions can be obtained from microfabricated gold nano-constrictions inside liquid media. Electromigration of junctions in air produces the highest yield (61 %), electromigration in deionized water and mesitylene results in a lower yield than in air (44–48 %), whereas electromigration in ethanol fails to produce viable tunnel junctions due to interfering electrochemical processes. We map out the stability of the conductance characteristics of the resulting tunnel junctions and identify medium-specific operational conditions which have an impact on the yield of forming stable junctions. Furthermore, we highlight the unique challenges associated with working with arrays of large numbers of tunnel junctions in batches. Our findings will inform future efforts to build single-molecule sensors using on-chip integrated tunnel junctions. | Shyamprasad N. Raja; Saumey Jain; Javier Kipen; Joakim Jaldén; Göran Stemme; Anna Herland; Frank Niklaus | Materials Science; Nanoscience; Thin Films; Nanodevices; Nanofabrication | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65cf6c5be9ebbb4db98132d1/original/electromigrated-gold-nanogap-tunnel-junction-arrays-fabrication-and-electrical-behavior-in-liquid-and-gaseous-media.pdf |
64c281b9658ec5f7e545530c | 10.26434/chemrxiv-2023-8sc6z-v2 | Communication J Chem Phys : Machine Learning Classification can Significantly
Reduce the Cost of Calculating the Hamiltonian
Matrix in CI Calculations | Hamiltonian matrices in electronic and nuclear contexts are highly compute-intensive to calculate, mainly due to the cost for the potential matrix. Typically these matrices
contain many off-diagonal elements that are orders of magnitude smaller than diagonal elements. We illustrate that here for vibrational H-matrices for H2O, C2H3 (vinyl)
and C2H5NO2 (glycine) using full-dimensional ab initio-based potential surfaces. We then show that many of the these small elements can be replaced by zero with small
errors of the resulting full set of eigenvalues, depending on the threshold value for this replacement. As a result of this empirical evidence, we investigate three machine
learning approaches to predict the zero elements. This is shown to be successful for these H-matrices after training on a small set of calculated elements. For one vinyl
and glycine H-matrices, of order 15 552 and 8 828, respectively, training on a percent or so of elements is sufficient to obtain all eigenvalues with a mean absolute error of roughly 2 cm-1. | Chen Qu; Paul Houston ; Qi Yu ; Riccardo Conte ; Priyanka Pandey ; Apurba Nandi; Joel Bowman | Theoretical and Computational Chemistry; Theory - Computational; Machine Learning | CC BY 4.0 | CHEMRXIV | 2023-07-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64c281b9658ec5f7e545530c/original/communication-j-chem-phys-machine-learning-classification-can-significantly-reduce-the-cost-of-calculating-the-hamiltonian-matrix-in-ci-calculations.pdf |
6572b8ec5bc9fcb5c957e378 | 10.26434/chemrxiv-2023-47vzs | Exosome-Drug Conjugates Delivery: a Promising Strategy for Improving the Solubility and Bioavailability of Artesunate | Artesunate (ATS) is considered the most widely employed artemisnin derivative in the treatment of Plasmodium falciparum malaria. However, poor solubility and low bioavailability of ATS limit its further clinical application. Herein, we developed a new strategy based on the exosome-drug conjugation (EDC) using the milk-derived exosomes for ATS delivery. The exosome-ATS conjugates (EACs) which formed via a facile bio-conjugation of ATS to the exosomal surface, have been demonstrated to be able to boost the solubility and bioavailability of ATS. Maximal improvement of 71.4-fold in the solubility of ATS was attained using EACs. The corresponding entrapment efficiency and drug loading capacity were found to be 90.3% and 73.9% for EACs, respectively. Further, in vivo pharmacokinetics study manifested that a nearly 5-fold higher peak plasma concentration (Cmax) of ATS than the free ATS was achieved by oral administration of EACs, leading to maximum 2.6-fold improved bioavailability of ATS. Moreover, EACs displayed a distinct sustained-release profile of maximum 36.2-fold prolonged half-life of ATS via intravenous delivery. We reported that for the first time the administration of EACs could be a potential drug delivery strategy for ameliorating the pharmacokinetic profile of ATS based on our encouraging results and hoped that our work opened up a new avenue for the development of EDC delivery system. | Da Wang; Yunfei Bai; Guogang Cheng; Shengqiang Shen; Gengwu Xiao; Qing Meng; Demei Ma; Ganggang Zhao; Mei Bai; Wei Chen; Tianshi Li; Litao Zhang; Xiaohu Ge | Materials Science; Nanoscience; Biological Materials; Controlled-Release Systems; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-05-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6572b8ec5bc9fcb5c957e378/original/exosome-drug-conjugates-delivery-a-promising-strategy-for-improving-the-solubility-and-bioavailability-of-artesunate.pdf |
665f180391aefa6ce1c4cd60 | 10.26434/chemrxiv-2024-dhl01 | Refractory Plasmonic Material based Floating Solar Still for Simultaneous Desalination and Electricity Generation | Established desalination technologies such as thermal distillation and reverse osmosis require advanced infrastructure and costly installation limiting their widespread implementation. Floating interfacial solar evaporation devices are considered a land-saving, environmentally friendly, and low infrastructure approach for freshwater production. Addressing issues related to maximum heat localization, prevention of salt accumulation and operating under stressful environmental conditions are some of the major challenges with floating solar desalination. This project presents an experimental demonstration of a plasmonic TiC nanoparticle-based floating solar still that can operate continuously under sunlight to produce clean water while floating on saline water sources. All materials, such as the PVC plastic condensation dome, EVA foam support, cotton wicks, and polyester filter fabric were chosen carefully to maximize the freshwater output of the solar still. The outdoor experiments were conducted in Halifax, Canada, where modest solar insolation of around 6 kW m-2 day-1 led to daily water yields up to 3.67 L m-2. The water can be produced at costs as low as $0.0086 L-1, and the solar still can be easily modified to generate thermoelectricity. This could allow for small onboard devices to test water quality without the need for an external electricity source. The results of this study will contribute to further development of floating solar desalination to provide potable water for water-stressed communities. | Matthew Margeson; Mark Atwood; Jaser Lara de Larrea; Joseph Weatherby; Heather Daurie; Katlyn Near; Graham Gagnon; Mita Dasog | Materials Science; Nanoscience; Earth, Space, and Environmental Chemistry; Carbon-based Materials; Wastes; Plasmonic and Photonic Structures and Devices | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/665f180391aefa6ce1c4cd60/original/refractory-plasmonic-material-based-floating-solar-still-for-simultaneous-desalination-and-electricity-generation.pdf |
60c751aef96a00164f28807a | 10.26434/chemrxiv.13203641.v1 | Dual Color Imaging from a Single BF2-Azadipyrromethene Fluorophore Demonstrated in vivo for Lymph Node Identification | <p>Dual color fluorescence imaging has been
achieved in the highly complex biomedical scenario of lymph node mapping. Emissions at 700 and 800 nm can be achieved
from a single fluorophore by establishing molecular and aggregate forms. Fluorophore was compatible with clinical
systems for fluorescence guided surgery and no toxicity was observed in high
dosage testing.</p> | Niamh Curtin; Dan Wu; Ronan A. Cahill; Anwesha Sarkar; Pól Mac Aonghusa; Sergiy Zhuk; Manuel Barberio; Mahdi Al-Taher; Jacques Marescaux; Michele Diana; Donal O'Shea | Bioorganic Chemistry; Photochemistry (Org.); Supramolecular Chemistry (Org.); Aggregates and Assemblies; Dyes and Chromophores; Surfactants; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c751aef96a00164f28807a/original/dual-color-imaging-from-a-single-bf2-azadipyrromethene-fluorophore-demonstrated-in-vivo-for-lymph-node-identification.pdf |
62ab9c204483988df478b293 | 10.26434/chemrxiv-2022-bmqkk | Cellular Exposure to Chloroacetanilide Herbicides Induces Distinct Protein Destabilization Profiles
| Herbicides in the popular chloroacetanilide class harbor a potent electrophilic moiety, which can damage proteins through nucleophilic substitution. In general, damaged proteins are subject to misfolding. Accumulation of misfolded proteins compromises cellular integrity by disrupting cellular proteostasis networks, which can further destabilize the cellular proteome. While direct conjugation targets can be discovered through affinity-based protein profiling, there are few approaches to probe how cellular exposure to toxicants impacts the stability of the proteome. We apply a quantitative proteomics methodology to identify chloroacetanilide-destabilized proteins in HEK293T cells based on their binding to the H31Q mutant of the human Hsp40 chaperone DNAJB8. We find that brief cellular exposure to the chloroacetanilides acetochlor, alachlor, and propachlor induces misfolding of dozens of cellular proteins. These herbicides feature distinct but overlapping profiles of protein destabilization, highly concentrated in proteins with reactive cysteine residues. Propachlor induces a general increase in protein aggregation, and selectively targets GAPDH and PARK7, leading to a decrease in their cellular activities. GAPDH is primarily modified by direct conjugation of propachlor at a catalytic cysteine residue, leading to global destabilization of the protein. The Hsp40 affinity strategy is an effective technique to profile cellular proteins that are destabilized by cellular toxin exposure.
Raw proteomics data is available through the PRIDE Archive at PXD030635.
| Guy Quanrud; Sunil Balamurugan; Carolina Canizal; Joseph Genereux | Biological and Medicinal Chemistry; Agriculture and Food Chemistry; Chemical Biology; Environmental biology | CC BY 4.0 | CHEMRXIV | 2022-06-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62ab9c204483988df478b293/original/cellular-exposure-to-chloroacetanilide-herbicides-induces-distinct-protein-destabilization-profiles.pdf |
60c75317702a9b1e4f18c2f3 | 10.26434/chemrxiv.13386458.v1 | Mixed Hierarchical Local Structure in a Disordered Metal–Organic Framework | Amorphous metal–organic frameworks (MOFs) are an emerging class of materials. However, their structural characterisation represents a significant challenge. Fe‑BTC, and the commercial equivalent Basolite® F300, are MOFs with incredibly diverse catalytic ability, yet their disordered structures remain poorly understood. Here, we use advanced electron microscopy to identify a nanocomposite structure of Fe‑BTC where nanocrystalline domains are embedded within an amorphous matrix, whilst synchrotron total scattering measurements reveal the extent of local atomic order within Fe‑BTC. We use a polymerisation-based algorithm to generate an atomistic structure for Fe-BTC, the first example of this methodology applied to the amorphous MOF field outside the well-studied zeolitic imidazolate framework family. This demonstrates the applicability of this computational approach towards the modelling of other amorphous MOF systems with potential generality towards all MOF chemistries and connectivities. We find that the structures of Fe-BTC and Basolite® F300 can be represented by models containing a mixture of short- and medium-range order with a greater proportion of medium-range order in Basolite® F300 than in Fe-BTC. We conclude by discussing how our approach may allow for high-throughput computational discovery of functional, amorphous MOFs. | Adam Sapnik; Irene Bechis; Sean M. Collins; Duncan Johnstone; Giorgio Divitini; Andrew J Smith; Philip A. Chater; Mathew Addicoat; Tim Johnson; David
A. Keen; Kim Jelfs; Thomas Bennett | Hybrid Organic-Inorganic Materials; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-12-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75317702a9b1e4f18c2f3/original/mixed-hierarchical-local-structure-in-a-disordered-metal-organic-framework.pdf |
65f894bbe9ebbb4db9f76cb5 | 10.26434/chemrxiv-2024-86w74 | The effects of mixed metal oxide catalysts on the synthesis of cyclic carbonates from epoxides under atmospheric CO2 pressure. | One use of CO2 as a starting material in organic transformations is in the synthesis of cyclic carbonates and polycarbonates. Due to the low reactivity of CO2, this transformation must be carried out in the presence of an efficient catalyst. Although several catalytic systems have been developed in the last decade, reducing the CO2 pressure at which the reaction is carried out remains one of the main challenges of the process. In this context, in the present work, we describe the catalytic activity of mixed metal oxides (MMOs) in the synthesis of cyclic carbonates from CO2 (1 atm) and epoxides at 70 °C. The use of these materials as catalysts represents a great advantage since they are highly stable and economical and can be reused in several reaction cycles. | Blanca Ivonne Vergara-Arenas ; Rachel L. Nicholls; Guillermo E. Negrón-Silva; Leticia Lomas-Romero; Jose Antonio Morales-Serna; Bao N. Nguyen | Catalysis; Heterogeneous Catalysis | CC BY 4.0 | CHEMRXIV | 2024-03-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65f894bbe9ebbb4db9f76cb5/original/the-effects-of-mixed-metal-oxide-catalysts-on-the-synthesis-of-cyclic-carbonates-from-epoxides-under-atmospheric-co2-pressure.pdf |
665402e221291e5d1d5ac9b3 | 10.26434/chemrxiv-2024-mk5lc | Catalytic Decarbonylation of Unstrained Diaryl Ketone Moieties to 2,2′-Bipyridyls Enabled by Electron-Deficient Pd Ensembles | Although decarbonylation of carbonyl compounds have attracted much attention for the direct molecular transformations of universal carbonyl moieties into useful compounds, reports on the catalytic decarbonylation of diaryl ketones are scarce. In this study, we successfully developed a catalytic decarbonylation of unstrained diaryl ketone moieties in compounds bearing bidentate directing groups to obtain 2,2′-bipyridyls using a CeO2-supported Cu–Pd alloy nanoparticle catalyst. The catalyst characterization and a series of control experiments revealed that the decarbonylation was efficiently catalyzed by Pd(0) ensembles, which became electron-deficient upon alloying with a small amount of Cu(0) species. | Takehiro Matsuyama; Takafumi Yatabe; Tomohiro Yabe; Kazuya Yamaguchi | Organic Chemistry; Catalysis; Organic Synthesis and Reactions; Heterogeneous Catalysis; Nanocatalysis - Reactions & Mechanisms | CC BY NC ND 4.0 | CHEMRXIV | 2024-05-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/665402e221291e5d1d5ac9b3/original/catalytic-decarbonylation-of-unstrained-diaryl-ketone-moieties-to-2-2-bipyridyls-enabled-by-electron-deficient-pd-ensembles.pdf |
60c741cc337d6c6b45e26934 | 10.26434/chemrxiv.8132747.v1 | On the Unsuspected Role of Multivalent Metal Ions on the Charge Storage of a Metal Oxide Electrode in Mild Aqueous Electrolytes | <p>The main objective of the work is to elucidate and rationalize the role played by an Al<sup>3+</sup>-based aqueous electrolyte on the charge accumulated in model mesoporous TiO<sub>2</sub> electrodes and to decipher the chemical nature of the inserting cation.<br /></p> | Yee-Seul Kim; Kenneth D. Harris; Benoit Limoges; Véronique Balland | Electrochemistry; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2019-05-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c741cc337d6c6b45e26934/original/on-the-unsuspected-role-of-multivalent-metal-ions-on-the-charge-storage-of-a-metal-oxide-electrode-in-mild-aqueous-electrolytes.pdf |
67c93f10fa469535b9273c1e | 10.26434/chemrxiv-2025-n1zhn | Role of electrolyte concentration on reversible Al3+ ion intercalation in graphene mediated anatase Titanium dioxide. | The electrochemistry of Al3+ ion in aqueous electrolytes is an interesting field of study. In this work, we have explored the feasibility of Al3+ ion insertion and extraction in graphene doped titanium dioxide (TiO2) microspheres through cyclic voltammetry and galvanostatic charge/discharge experiments. We present a one-step hydrothermal synthesis technique for producing spherical shape Graphene-TiO2. Our findings show that the kinetics of Al3+ ion insertion and extraction are significantly influenced by the concentration of aqueous electrolyte. | Homen Lahan; Ravi Kumar; Nishchith B S | Materials Science; Nanoscience; Energy; Carbon-based Materials; Nanostructured Materials - Materials; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c93f10fa469535b9273c1e/original/role-of-electrolyte-concentration-on-reversible-al3-ion-intercalation-in-graphene-mediated-anatase-titanium-dioxide.pdf |
622902b8011b58c9fbc3d240 | 10.26434/chemrxiv-2022-0t3fr | Exchange Spin Coupling in Optically Excited
States | In optically excited states in molecules and materials, coupling between local electron spins plays an important role for their photoemission properties and is interesting for potential applications in quantum information processing. Recently, it was experimentally demonstrated that the photogenerated local spins in donor–acceptor metal complexes can interact with the spin of an attached radical, resulting in a spin-coupling
dependent mixing of excited doublet states, which controls the local spin density distributions on donor, acceptor, and radical subunits in optically excited states. In this work, we propose an energy-difference scheme to evaluate spin coupling in optically excited states, using unrestricted and spin-flip simplified time-dependent density functional theory (sTDDFT). We apply it to three platinum complexes which have been studied experimentally to validate our methodology. We find that all computed coupling constants are in excellent agreement with the experimental data. In addition,
we show that the spin coupling between donor and acceptor in the optically excited state can be fine-tuned by replacing platinum with palladium and zinc in the structure. Besides the two previously discussed excited doublet states (one bright and one dark), our calculations reveal a third, bright excited doublet state which was not considered previously. This third state possesses the inverse spin polarization on donor
and acceptor with respect to the previously studied bright doublet state and is by an order of magnitude brighter, which might be interesting for optically controlling local spin polarizations with potential applications in spin-only information transfer and
manipulation of connected qubits. | Torben Steenbock; Lawrence L.M. Rybakowski; Dominik Benner; Carmen Herrmann; Gabriel Bester | Theoretical and Computational Chemistry; Inorganic Chemistry; Organometallic Chemistry; Magnetism; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2022-03-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/622902b8011b58c9fbc3d240/original/exchange-spin-coupling-in-optically-excited-states.pdf |
64c3b4b0658ec5f7e551e0b9 | 10.26434/chemrxiv-2023-jvmz1 | Light-controlled inhibition of the circadian regulator RORγ | Retinoic acid receptor-related orphan receptor γ (RORγ) is a circadian regulator and has emerged as experimental therapeutic target in inflammation and immunity. The cyclic temporal role of RORγ in circadian rhythms makes temporally-resolved pharmacological control of this receptor particularly intriguing. To achieve next-generation tools to study RORγ biology, we designed RORγ ligands featuring a central azobenzene photoswitch, that act as light-dependent inverse agonists. Structural optimization enabled efficient photocontrol over RORγ inhibition, with remarkable potency on RORγ and excellent selectivity over related receptors. These high-specificity photopharmaceuticals can serve as high-precision tools to study the dynamic modulation of RORγ in signaling pathways and in inflammatory disorders. | Martin Reynders; Sabine Willems; Julian A. Marschner; Thomas Wein; Daniel Merk; Oliver Thorn-Seshold | Biological and Medicinal Chemistry; Organic Chemistry; Bioorganic Chemistry; Cell and Molecular Biology; Chemical Biology | CC BY NC 4.0 | CHEMRXIV | 2023-07-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64c3b4b0658ec5f7e551e0b9/original/light-controlled-inhibition-of-the-circadian-regulator-ror.pdf |
65103955b927619fe7bb48a8 | 10.26434/chemrxiv-2023-gq113 | Imine Reductase Cascades for the Synthesis of Saturated N-Heterocycles | Saturated N-heterocycles constitute a vital scaffold for pharmaceutical chemistry, but are challenging to access synthetically, particularly in asymmetric mode. Here we demonstrate how imine reductases can achieve annulation through tandem inter and intramolecular reductive amination processes. Imine reductases were used in combination with further enzymes to access un-substituted, α-substituted and α,α’-disubstituted N-heterocycles from simple starting materials, in one pot and under benign conditions. The work was exemplified in regard to product scope and a new route to the valuable natural product nicotine was demonstrated. | Nicholas Turner; Jeremy Ramsden; Bruna Costa; Rachel Heath; James Marshall; Juan Mangas-Sanchez; Sarah Montgomery; Keith Mulholland; Sebastian Cosgrove | Biological and Medicinal Chemistry | CC BY 4.0 | CHEMRXIV | 2023-09-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65103955b927619fe7bb48a8/original/imine-reductase-cascades-for-the-synthesis-of-saturated-n-heterocycles.pdf |
67d385f3fa469535b926c5b4 | 10.26434/chemrxiv-2025-sgh3d | Photocatalyst-free, visible-light-mediated copper catalysed S-arylation of sulfenamides with aryl thianthrenium salts | The site-selective incorporation of sulfilimine functionalities into aromatic compounds provides a vital strategy for drug discovery in medicinal chemistry. However, the green and sustainable methods for realizing the goal are still limited and urgently need to be developed. Here, we reported a copper-catalyzed S-arylation of sulfenamides with aryl thianthrenium salts irradiated by visible light without the photocatalyst, which exhibited fine functional-group compatibility and gave the desired products with high yields. Notably, the reaction could be performed in PBS buffer and water. Mechanistic investigations revealed that the key to achieving these results is the generation of an EDA complex between sulfenamides and aryl thianthrenium salts under basic conditions. Furthermore, gram-scale reactions and divergent transformations were successfully realized under mild conditions, underscoring the practicality of the methodology. | Hongyu Wang; Xiangyu Zhuang; Hao Li; Zhaoyu Feng | Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67d385f3fa469535b926c5b4/original/photocatalyst-free-visible-light-mediated-copper-catalysed-s-arylation-of-sulfenamides-with-aryl-thianthrenium-salts.pdf |
65c31833e9ebbb4db9d42a58 | 10.26434/chemrxiv-2024-ngmch-v3 | Development of lignin-based biodegradable polymer from
Agro-waste | Biosourced and biodegradable polymers have garnered substantial attention for their role as sustainable and environmentally friendly alternatives to traditional synthetic polymers, finding diverse applications across various fields. The escalating global demand for food production and a surge in agricultural activities have resulted in a significant increase in agro-waste generation. In India, an agro-waste annual output ranging between 85-100 million tonnes is observed, with wheat straws contributing substantially to approximately one-third of the total agro residue [6]. Addressing the challenge of agro-waste utilisation, we present an innovative methodology for converting wheat straw into a Biodegradable polymer (acetyl ferulic acid polymer). The process involves the extraction of lignin through an acid-base neutralisation reaction, with the qualitative confirmation of lignin presence achieved through Safranin dye testing. The extracted lignin undergoes oxidation via the Nitrobenzene Oxidation (NBO) method, facilitating the conversion into Vanillin through sidechain oxidation of the complex lignin structure. The subsequent acetylation of Vanillin is carried out to obtain acetyl ferulic acid, which is then polymerised utilising zinc acetate as a catalyst. Glycerol is employed as a plasticiser, and the biodegradability of the resulting polymer is assessed within a controlled ambient decomposition environment in the laboratory. Decomposition data is subjected to modelling using Wolfram Mathematica, yielding the decomposition time. Our findings assert that the developed biodegradable polymer requires approximately 105 days to decompose, achieving a degradation rate of approximately 99.98%. This newly synthesised biopolymer is posited to exhibit compatibility with existing biodegradable polymers, thus contributing to the advancement of sustainable polymer materials. | Sameer Sharma; Swagatika Moharana; Akash Kumar Sharma; Aasheesh Srivastava | Polymer Science; Agriculture and Food Chemistry; Biopolymers; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2024-02-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65c31833e9ebbb4db9d42a58/original/development-of-lignin-based-biodegradable-polymer-from-agro-waste.pdf |
65b89e0066c13817298de9ea | 10.26434/chemrxiv-2024-7d3n6 | The Chan-Lam-type synthesis of thioimidazolium salts for thiol-(hetero)arene conjugation | The design of stable and variable aryl linkers for conjugating drug moieties to the metabolism-related thiols is of importance in drug discovery, especially in the field of antibody-drug conjugates (ADCs). We disclosed that thioimidazolium groups are unique scaffolds for the thiol-(hetero)arene conjugation under mild conditions. The drug bound thioimidazolium salts, which are easily accessible via a copper-mediated Chan-Lam process in gram-scale, could be successfully applied to the late-stage coupling of bioactive thiols to construct a broad array of drug-like molecules. | Yue Li; Dongchang Han; Zhibin Luo; Xiaomeng Lv; Bin Liu | Organic Chemistry; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65b89e0066c13817298de9ea/original/the-chan-lam-type-synthesis-of-thioimidazolium-salts-for-thiol-hetero-arene-conjugation.pdf |
63658d7bee318630c47ff449 | 10.26434/chemrxiv-2022-xgxs8 | Modeling Catalyzed Reactions on Metal-Doped Amorphous Silicates: The Case of Niobium-Catalyzed Ethylene Epoxidation | Metal-doped amorphous silicates are promising materials for heterogeneous catalysis, be- cause they are easy to make and their properties can be tuned for specific reactions. However, the amorphous nature of the surface makes the characterization difficult, and improvements are based on a trial and error approach. Density functional theory simulations can in principle provide direct structure-property relations, but the sampling of the active site configuration space is not possible via brute force. In this contribution, we use the Nb-catalyzed epoxidation of ethylene as a test reaction to analyze various aspects of the modeling that need to be taken into account for simulations of effective reaction rates. We show that each site can host a variety of transition state structures that represent the same reaction event, but that can differ considerably in reaction barrier. Furthermore, many different sites need to be sampled. We then use machine learning to identify the most important descriptors of the bare active site that correlate directly with the energy barrier. Al- though our test set is too small for quantitative predictions of reaction rates, we discuss what the important features of a very active site are that can drive the kinetics in the real material. | Kaihua Zhang; Marco Caricato | Theoretical and Computational Chemistry; Catalysis; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-11-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63658d7bee318630c47ff449/original/modeling-catalyzed-reactions-on-metal-doped-amorphous-silicates-the-case-of-niobium-catalyzed-ethylene-epoxidation.pdf |
6564b07429a13c4d471bfd86 | 10.26434/chemrxiv-2023-vx3hm | Biorthogonal masked acylating agents for proximity-dependent RNA labeling | RNA subcellular localization is highly regulated, with local enrichment driving geography- dependent cell physiology. While proximity-based labeling technologies that use highly reactive radicals or carbenes provide a powerful method for unbiased mapping of protein organization within a cell, methods for unbiased RNA mapping are scarce and comparably less robust. In this work, we develop novel α-alkoxy thioenol and chlorenol esters, which function as potent acylating agents upon controlled ester unmasking. We pair these probes with subcellular-localized expression of a bioorthogonal esterase to establish a novel method for spatial analysis of RNA: Bioorthogonal Acylating agents for Proximity labeling and sequencing (BAP-seq). We demonstrate that by selectively unmasking the enol probe in a locale of interest, we can map RNA distribution in membrane-bound and membrane-less organelles. The controlled-release acylating agent chemistry and corresponding BAP-seq method expands the scope of proximity labeling technologies and provides a powerful approach to interrogate the cellular organization of RNAs. | Shubhashree Pani; Tian Qiu; Kaitlin Kentala; Saara-Anne Azizi; Bryan Dickinson | Biological and Medicinal Chemistry; Organic Chemistry; Biochemistry; Cell and Molecular Biology; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2023-11-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6564b07429a13c4d471bfd86/original/biorthogonal-masked-acylating-agents-for-proximity-dependent-rna-labeling.pdf |
6731d03a5a82cea2fabff8f9 | 10.26434/chemrxiv-2024-r66k2 | Discovery of a Concerted Mechanism in Arylmalonate Decarboxylase Expands the Catalytic Scope for Cofactor-free C-C Bond Cleavage | The cofactor-free arylmalonate decarboxylase (AMDase) has been applied for the synthesis of a large number of α-aryl and α-alkenylcarboxylic acids with outstanding stereoselectivity. We observed that (S)-selective AMDase variant ICPLLG produces a single product enantiomer from 2-methyl-2-phenyl malonate with 99% ee (S), but both product enantiomers from 2-methyl-2-vinyl malonate with 66% ee (S). This prompted us to investigate its mechanism. In the decarboxylation of an isotope-labeled, pseudochiral substrate, we observed that the AMDase variant decarboxylates alkenyl malonates only with inversion of the configuration at the α-C atom. This differs from the decarboxylation of arylmethyl malonates, which proceeds with retention. Further mechanistic investigations with kinetic isotope measurements and QM/MM well-tempered metadynamics calculations suggest an enforced concerted mechanism for the decarboxylation of alkenyl malonic acids, which explains the different stereochemical outcome. The alternative binding mode identified in this study, accounts for the decarboxylation of 2-ethyl-2-vinyl malonate in outstanding stereoselectivity, a substrate that is not converted by wild-type AMDase. Our work sheds light on a new mechanism how enzymes can cleave C-C bonds without support of an organic cofactor. The gained mechanistic understanding will provide guidance for future protein engineering efforts. | Elske van der Pol; Thomas Schlatzer; Gyula Hoffka; Bruno di Geronimo; Johannes Eder; Anna Katharina Schweiger; Marianna Karava; Roland Fischer; Daniel Kracher; Dominik Gross; Romas Kazlauskas; Kenji Miyamoto; Shina Caroline Lynn Kamerlin; Rolf Breinbauer; Robert Kourist | Theoretical and Computational Chemistry; Organic Chemistry; Catalysis; Computational Chemistry and Modeling; Biocatalysis | CC BY 4.0 | CHEMRXIV | 2024-11-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6731d03a5a82cea2fabff8f9/original/discovery-of-a-concerted-mechanism-in-arylmalonate-decarboxylase-expands-the-catalytic-scope-for-cofactor-free-c-c-bond-cleavage.pdf |
670e40fb51558a15ef2205d8 | 10.26434/chemrxiv-2024-n9q36 | Method and theory of genome profiling (GP) developed for identification and classification of organisms | Details of the method and theory on the genome profiling (GP), which provides with the method for species identification and classification of organisms, are first described. GP consists of three major steps: i.e., random PCR, micro-temperature gradient gel electrophoresis (μTGGE), and extraction and processing of featuring points contained in genome profiles (results of the former step) generating species identification dots (spiddos). Methodological, physical and biological meanings of ‘random PCR’, ‘μTGGE’, ‘spiddos’, ‘genome distance (dG)’ and others introduced in this study are originally discussed. This paper gives a base for understanding the diversity of GP achievements performed for 30 years written in an alternative review on GP (i.e., to appear in Briefings in Functional Genomics (in process)), especially underscoring the importance of the spiddos parameter for calculating closeness of species and constructing genome database.
Spiddos contains such a kind of information termed as SIOWS (sequence information obtained without sequencing), which is essentially unique and important for the GP technology, derived from the sequence-specific DNA melting phenomenon together with DNA melting theory. Succeedingly, one can understand why GP enables us to draw the sufficient amount of information without sequencing of genomic DNA. This also explains why identification/classification of species can be so readily and universally done by GP. It requires the perspective on the nature of spiddos. Since this paper first provides detailed procedures of GP and in-depth theoretical explanation of the GP-related phenomena, a wide range of scientists (Bacteriology, Infectious Disease Medicine, Epidemiology, Environmental Science, Biodiversity Science, Mutagen Research, Taxonomy, Bio-database Science, and others) can engage in applications of GP, which is difficult without sufficient understanding of the method and theory of GP. | Koichi Nishigaki | Biological and Medicinal Chemistry; Analytical Chemistry; Chemical Engineering and Industrial Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-10-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/670e40fb51558a15ef2205d8/original/method-and-theory-of-genome-profiling-gp-developed-for-identification-and-classification-of-organisms.pdf |
60c751fdbb8c1adc133dbde3 | 10.26434/chemrxiv.13238066.v1 | How Natural Materials Remove Heavy Metals from Water: Mechanistic Insights from Molecular Dynamics Simulations | Heavy metals are captured by hemicellulose from water: modeling and simulations. Classical and ab initio molecular dynamics aided by metadynamics. Relevant to the understanding of removal of heavy metals from water sources with natural materials, e.g. spent coffee grains. | Fabio Pietrucci; Mauro Boero; Wanda Andreoni | Environmental Science; Hydrology and Water Chemistry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c751fdbb8c1adc133dbde3/original/how-natural-materials-remove-heavy-metals-from-water-mechanistic-insights-from-molecular-dynamics-simulations.pdf |
62a43a51bb7519c3db4a36a7 | 10.26434/chemrxiv-2022-j348w | Pyridine N-oxides as HAT reagents for photochemical C-H functionalization of electron-deficient heteroarenes | Pyridine N-oxides only recenly marked their presence in the photocatalysis outbreak, mainly serving as oxypyridinium salt precursors. Herein, their unique reactivity as a hydrogen atom transfer reagent in photochemical, Minisci-type alkylation of electron-deficient heteroarenes is unveiled. The formation of an EDA complex between a heterocyclic substrate and N-oxide precludes the need for a photocatalyst. The developed method allows for a broad range of radical precursors to be used, namely alkanes, alkenes, amides, and ethers, for efficient alkylation of azines. | Łukasz Ciszewski; Dorota Gryko | Organic Chemistry; Photochemistry (Org.) | CC BY NC ND 4.0 | CHEMRXIV | 2022-06-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62a43a51bb7519c3db4a36a7/original/pyridine-n-oxides-as-hat-reagents-for-photochemical-c-h-functionalization-of-electron-deficient-heteroarenes.pdf |
64fadf6199918fe537936d60 | 10.26434/chemrxiv-2023-gvnpg | Driving Micro-Objects Using Optical Force due to Photoemission | Emission of fluorescence in a specific direction generates an optical force in the opposite direction of the emission by the momentum conservation raw. This "emission force" can induce the directional transportation of a tiny object anisotropically emitting fluorescence from dye molecules incorporated in the object, leading to the realization of the controlled actuation of a tiny object only by the light irradiation. To demonstrate the movement by using the emission force, we prepared dye-doped cylinder-shaped polymer micro-object one top of which was covered with gold thin film. Under visible (532 nm) light illumination on a glass surface in water, the dyes emitted strong fluorescence towards the other non-coated end of the micro-cylinder due to the reflection by the gold thin film. Analysis of the trajectory of tiny objects confirmed that this anisotropic fluorescence emission led to the transportation of the micro-objects in the opposite direction of the fluorescence. The emission force acting on the polymeric micro-objects was quantitatively evaluated through computational simulation taking into account the emission force and Brownian motion. | Syoji Ito; Takayuki Nanno; Takahiro Kaji; Mamoru Tamura; Takuya Iida; Hiroshi Miyasaka | Physical Chemistry; Materials Science; Nanoscience; Optics; Photochemistry (Physical Chem.); Robotics | CC BY NC ND 4.0 | CHEMRXIV | 2023-09-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64fadf6199918fe537936d60/original/driving-micro-objects-using-optical-force-due-to-photoemission.pdf |
60c74ae6f96a0022f8287512 | 10.26434/chemrxiv.12249458.v1 | Artificial Applicability Labels for Improving Policies in Retrosynthesis Prediction | Automated retrosynthetic planning algorithms are
a research area of increased importance. Automated reaction template extraction
from large datasets in conjunction with neural network enhanced tree search
algorithms can find plausible routes to target compounds in seconds. However,
the current way of training the neural networks to predict suitable templates
for a given target product, leads to many predictions which are not applicable <i>in silico</i>. Most templates in the top-50
suggested templates can’t be applied to the target molecule to perform the
virtual reaction. Here we describe how to generate data and train a neural
network policy that predicts if templates are applicable or not. First, we
generate a massive training dataset by applying each retrosynthetic template to
each product from our reaction database. Second, we train a neural network to
near perfect prediction of the applicability labels on a held-out test set. The
trained network is then joined with a policy model trained to predict and
prioritize templates using the labels from the original dataset. The combined
model was found to outperform the policy model in a route-finding task using
1700 compounds from our internal drug discovery projects. | Esben Jannik Bjerrum; Amol Thakkar; Ola Engkvist | Organic Synthesis and Reactions; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74ae6f96a0022f8287512/original/artificial-applicability-labels-for-improving-policies-in-retrosynthesis-prediction.pdf |
60c75528bb8c1a10e53dc37d | 10.26434/chemrxiv.14046449.v1 | Wide Bite Angle Disphosphine Ligands in Thermally Activated Delayed Fluorescent Copper(I) Complexes: Impact on the Performance of Electroluminescence Applications | <p>We report a series of seven cationic heteroleptic copper(I) complexes of the form [Cu (P^P) (dmphen)]BF<sub>4</sub>, where dmphen is 2,9-dimethyl-1,10-phenanthroline and P^P is a diphosphine chelate, in which the effect of the bite angle of the diphosphine ligand on the photophysical properties of the complexes was studied. Several of the complexes exhibit moderately high photoluminescence quantum yields in the solid-state, with Φ<sub>PL</sub> of up to 35%, and in solution, with Φ<sub>PL</sub> of up to 98%. We were able to correlate the powder photoluminescence quantum yields with the %V<sub>bur</sub> of the P^P ligand. The most emissive complexes were used to fabricate both organic light-emitting diodes (OLEDs) and light-emitting electrochemical calls (LECs), both of which showed moderate performance. Compared to the benchmark Cu(I)-based LECs, [Cu(dnbp)(DPEPhos)]<sup>+ </sup>(EQE<sub>max</sub> = 16%), complex <b>3</b> (EQE<sub>max</sub> = 1.85%) showed much longer device lifetime (t<sub>1/2 </sub>= 1.25 h and >16.5 h for [Cu(dnbp)(DPEPhos)]<sup>+</sup> and complex <b>3</b>, respectively). The electrochemiluminescent properties of several complexes were also studied which to the best of our knowledge constitutes the first ECL study for heteroleptic copper (I) complexes. Notably, complexes exhibiting more reversible electrochemistry were associated with higher annihilation ECL as well as better performance in an LEC device.</p> | Chenfei Li; Campbell Mackenzie; Said Said; Amlan Pal; Mohammad Haghighatbin; Azin Babaei; Michele Sessolo; David Cordes; Alexandra Slawin; Paul Kamer; Henk Bolink; Conor Hogan; Eli Zysman-Colman | Coordination Chemistry (Organomet.); Ligands (Organomet.); Spectroscopy (Organomet.); Transition Metal Complexes (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-02-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75528bb8c1a10e53dc37d/original/wide-bite-angle-disphosphine-ligands-in-thermally-activated-delayed-fluorescent-copper-i-complexes-impact-on-the-performance-of-electroluminescence-applications.pdf |
66d6198412ff75c3a132c9bc | 10.26434/chemrxiv-2024-d2924-v2 | Large Mid-Infrared SHG Activities in Eu(II)-Based Quaternary Chalcogenides | Complex metal-chalcogenides have received growing attention for second-harmonic generation (SHG) activity arising from their noncentrosymmetric structures. In this area, the impact of the Eu(II)-cation on their structures and optical properties has not been well explored. Synthetic investigations of the Eu-Ag-IV-Ch (IV = Sn or Ge; Ch = S or Se) systems have unveiled four Eu(II)-based quaternary chalcogenides exhibiting very large mid-IR SHG responses within the chemically-rich systems II-I2-IV-Ch4 and II3-I2-IV2-Ch8 (Ch = S or Se; I, II, and IV = monovalent, divalent and tetravalent cations, respectively). Their structures were characterized by single-crystal X-ray diffraction (SCXRD) methods to crystallize in noncentrosymmetric space groups, I4 ̅2m for EuAg2GeS4 (1) and I4 ̅3d for Eu3Ag2Ge2Se8 (2) Eu3Ag2Sn2Se8 (3) and Eu3Ag2Sn2S8 (4). The structures consist of body-centered arrangements of (Ge/Sn)Ch4 tetrahedra that are fully oriented and bridged by flattened AgCh4 tetrahedra into 3D networks and charge-balanced by Eu(II) cations. Their crystalline powders exhibit mid-IR (2.09 µm) SHG responses among the largest reported to date, ranging from a large ~1.9 × AGS (AgGaS2) for1, to remarkably high activities of ~1.9 for 3, ~4.7 for 2, and ~7.0 for 4 × AGS. Spin-polarized band structure calculations showed the valence and conduction band edge states stem from interactions of the Ag-to-S/Se and Ge/Sn-to-S/Se based states, respectively, with increasing contributions of the Eu(II) 4f7-based in the order of 1 < 3 < 2 < 4. Interestingly, this trend correlates with the SHG activity, suggesting a potential new relationship for understanding and attaining cutting-edge SHG properties within Eu(II)-based chalcogenides. Thus, these results unveil a deeper understanding of structure-optoelectronic/SHG property relationships. | Subhendu Jana; Eric Gabilondo; Machima Mongkhonratanachai; Yujie Zhang; P. Shiv Halasyamani; Paul Maggard | Materials Science; Inorganic Chemistry; Optical Materials; Solid State Chemistry; Materials Chemistry; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d6198412ff75c3a132c9bc/original/large-mid-infrared-shg-activities-in-eu-ii-based-quaternary-chalcogenides.pdf |
60c75112bdbb897c4ca3a005 | 10.26434/chemrxiv.13041710.v3 | A Density Functional Theory Investigation of the Reaction of Water with Ce2O- | Cerium suboxide clusters are a recent catalyst class that has received interest for the generation of H<sub>2</sub> from water. Using density functional theory calculations, this work examines the reaction of Ce<sub>2</sub>O<sup>–</sup> clusters with H<sub>2</sub>O. It is shown that the reaction can proceed along both doublet and quartet pathways. In both cases, hydrogen formation is facilitated by intermediate structures featuring bridging hydride and hydroxide ligands. Interestingly, it is shown that metal d electrons facilitate the reduction of water. This work provides new understanding of this reaction and provides new insight into the reactivity of small lanthanide-based clusters with water.<br /> | Hassan Harb; Hrant Hratchian | Computational Chemistry and Modeling; Heterogeneous Catalysis; Fuels - Energy Science; Clusters | CC BY NC ND 4.0 | CHEMRXIV | 2021-06-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75112bdbb897c4ca3a005/original/a-density-functional-theory-investigation-of-the-reaction-of-water-with-ce2o.pdf |
648c867ce64f843f41e180bc | 10.26434/chemrxiv-2023-3vj07 | Reaction Kinetics of Complex Molecular Strains: The Efficiency of Mechanochemistry Under a Constant Total Energy | While the concept of mechanochemistry is not new, it is becoming significantly more prevalent in a wide variety of fundamental and industrial chemistry applications, especially in the condensed phase. However, condensed matter effects can result in complex non-linear deformations. Moreover, this highly relevant in reactions that include both thermal and mechanical influences on the reaction rate. Here we define a formalism that describes kinetic effect of molecular shape distortions as a sum over the normal modes and how those modes project onto the reactions path. By coupling this framework with a 'cost' function that defines the thermal and mechanical energy balance for a specific reaction condition, a general efficiency of the mechanochemistry is derived. We apply this concept to reactions in energetic materials where a shockwave of some energy can impart a distribution of both kinetic energy and molecular strains on the system. We derive under what conditions that mechanical energy is preferential or detrimental to local reaction rates. This workflow is general, with a proper cost function, can be applied to a wide variety of fundamental and industrial mechanochemical applications, where the cost function can define a wide range of energetic, environmental, and financial results based on changes to the reaction conditions. | Brenden W. Hamilton; Edward Kober; Timothy C Germann | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Chemical Kinetics; Physical and Chemical Processes | CC BY 4.0 | CHEMRXIV | 2023-06-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/648c867ce64f843f41e180bc/original/reaction-kinetics-of-complex-molecular-strains-the-efficiency-of-mechanochemistry-under-a-constant-total-energy.pdf |
60c755c04c8919af7cad4736 | 10.26434/chemrxiv.14157059.v1 | Acylboronates in Polarity-Reversed Generation of Acyl Palladium(II) Intermediates | We report a catalytic cross-coupling process between aryl (pseudo)halides and boron-based acyl anion equivalents. This mode of acylboronate reactivity represents polarity reversal, which is supported by the observation of tetracoordinated boronate and acyl palladium(II) species by <sup>11</sup>B, <sup>31</sup>P NMR, and mass spectrometry. A broad scope of aliphatic and aromatic acylboronates has been examined, as well as a variety of aryl (pseudo)halides. | Alina Trofimova; Aleksandra Holownia; chieh-hung tien; martynas sirvinskas; Andrei Yudin | Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-03-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c755c04c8919af7cad4736/original/acylboronates-in-polarity-reversed-generation-of-acyl-palladium-ii-intermediates.pdf |
6459057327fccdb3eab421b8 | 10.26434/chemrxiv-2023-2vvgx | Unravelling the Superiority of Nonbenzenoid Acepleiadylene as a Building Block for Organic Semiconducting Materials | Acepleiadylene (APD), a nonbenzenoid isomer of pyrene, exhibits a unique charge-separated character with a large molecular dipole and a small optical gap. However, APD has never been explored in optoelectronic materials to take advantage of these unique properties. Here, we employ APD as a building block in organic semiconducting materials for the first time, and unravel the superiority of nonbenzenoid APD in electronic applications. We have synthesized an APD derivative (APD-IID) with APD as the terminal donor moieties and isoindigo (IID) as the acceptor core. Theoretical and experimental investigations reveal that APD-IID has an obvious charge-separated structure and enhanced intermolecular interactions as compared with its pyrene-based isomers. As a result, APD-IID displays significantly higher hole mobilities than that of the pyrene-based counterparts. These results imply the advantages of employing APD in semiconducting materials and great potential of nonbenzenoid polycyclic arenes for optoelectronic applications. | Lin Fu; Pengcai Liu; Rui Xue; Xiao-Yu Tang; Jiawen Cao; Ze-Fan Yao; Yuchao Liu; Shouke Yan; Xiao-Ye Wang | Organic Chemistry; Materials Science; Organic Compounds and Functional Groups; Aggregates and Assemblies; Dyes and Chromophores; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-05-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6459057327fccdb3eab421b8/original/unravelling-the-superiority-of-nonbenzenoid-acepleiadylene-as-a-building-block-for-organic-semiconducting-materials.pdf |
60c73e130f50db65203955aa | 10.26434/chemrxiv.6301571.v1 | Two Faces of Hydrogen in Yttrium Hydroxyhydride: Y2H3O(OH) – a New Inorganic Chiral System with Hydridic and Protonic Hydrogens | Design of inorganic compounds containing different anions attracts a lot of attention because it affords a great opportunity to develop new functionality across the whole range of material properties. Based on the results of structure-modeling studies of a mixed-anion system, we predicted novel derivatives of oxyhydrides – chiral hydroxyhydrides M<sub>2</sub>H<sub>3</sub>O(OH) (M = Y, Sc, La, and Gd) that are characterized by the coexistence of three anionic species, H<sup>–</sup>, O2<sup> –</sup>, and OH<sup>–</sup> inside the crystal lattice. The materials demonstrate a specific charge ordering, which is connected with the chiral organization of atoms where both the metal cations and the anions are standing in positions that form helical curves spreading along the tetragonal axis. Moreover, the twisting of the H<sup>–</sup> and H<sup>+</sup> sites gives rise to their linking via strong dihydrogen bonds. Unusual structural, electron and optical features caused by the P4<sub>1</sub> crystal structure have been investigated in the Y<sub>2</sub>H<sub>3</sub>O(OH) comprehensive case study. | Aleksandr Pishtshev; Evgenii Strugovshchikov; Smagul Karazhanov | Optical Materials; Bonding; Coordination Chemistry (Inorg.); Solid State Chemistry; Theory - Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2018-05-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e130f50db65203955aa/original/two-faces-of-hydrogen-in-yttrium-hydroxyhydride-y2h3o-oh-a-new-inorganic-chiral-system-with-hydridic-and-protonic-hydrogens.pdf |
62f255281ea5f680fa6e28b2 | 10.26434/chemrxiv-2022-nv2g3 | Electron-beam chemistry in graphene - Effect of environmental SEM parameters on patterning and defect engineering | The engineering of defects in low-dimensional materials can enable the modulation of their optical, electrical, thermal, and structural properties. We have previously shown the ability to engineer precision patterned defects in graphene by electron beam irradiation in a controlled water vapor ambient within an environmental scanning electron microscope (ESEM). However, the relationship between instrumental parameters and structural changes in graphene are unexplored. Here, we investigate the relationships between parameters such as pressure, electron dose, and acceleration voltage on the electronic and structural properties of graphene as probed by Raman spectroscopy. There are dependencies on all of the studied parameters but electron dose is the dominant parameter that shows the most intense levels of structural modulation. Interestingly, control of instrumental parameters allows for the precision tailoring of features such as resolution (as determined by the beamskirting effect), doping, and functionalization – all of which make this process powerful for precision tuning of 2D materials and adds an enhanced technique for the development of next-generation electronics. | Ryan Selhorst; Michael Susner; Ryan Muzzio; I-Hsuan Kao; Jennifer Carpena-Nunez; Ahmad Islam; Jyoti Katoch; Benji Maruyama; Rahul Rao | Materials Science; Nanoscience; Carbon-based Materials; Materials Processing; Nanofabrication; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-08-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62f255281ea5f680fa6e28b2/original/electron-beam-chemistry-in-graphene-effect-of-environmental-sem-parameters-on-patterning-and-defect-engineering.pdf |
67be536981d2151a02159f9c | 10.26434/chemrxiv-2025-gc7s6-v2 | Defining stereoisomeric configuration spaces and subspaces for arbitrary coordination centres ABn | The range of geometric configurations possible for an arbitrary coordination centre ABn, is a key aspect of stereoisomerism and molecular geometry in general. Despite this, much focus within Chemistry concerning ABn geometries has not taken a rigorous and holistic approach. Using a precise definition for configurations based upon the interior angles at the A-atom, we present a general method for describing ABn configuration spaces or their subspaces. The method uses angle-changing molecular vibrational normal modes as a basis to locally describe the spaces. A consequence of using a physically inspired method is that the configuration spaces map onto physical mechanisms (“polytopal rearrangements”). The space of local configurations and their subspaces are amenable to compactifications modelled on chemical processes. A contiguous symmetry based discretisation method that allows for the configuration spaces to be encoded as graphs is presented. Numerous worked examples are given. | Peter Canfield; Maxwell Crossley; Jonathan Spreer; Stephan Tillmann | Theoretical and Computational Chemistry; Physical Chemistry; Theory - Computational; Physical and Chemical Processes; Structure | CC BY 4.0 | CHEMRXIV | 2025-02-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67be536981d2151a02159f9c/original/defining-stereoisomeric-configuration-spaces-and-subspaces-for-arbitrary-coordination-centres-a-bn.pdf |
62277d12daa4fbfa0d8418d6 | 10.26434/chemrxiv-2022-58mlf | Proton and Oxide Ion Conductivity in Palmierite Oxides | Solid proton and oxide ion conductors have key applications in several hydrogen-based and energy related technologies. Here we report on the discovery of significant proton and oxide ion conductivity in palmierite ox-ides A3V2O8 (A = Sr, Ba), which crystallize with a framework of isolated tetrahedral VO4 units. We show that these systems present prevalent ionic conduction, with a large protonic component under humidified air (tH = 0.6 – 0.8) and high protonic mobility. In particular, the proton conductivity of Sr3V2O8 is 1.0 x 10-4 S cm-1 at 600 °C, competitive with the best proton conductors constituted by isolated tetrahedral units. Simulations show that the three-dimensional ionic transport is vacancy driven and is facilitated by rotational motion of the VO4 units, which can stabilize oxygen defects via formation of V2O7 dimers. Our findings demonstrate that palmierite oxides are a new promising class of ionic conductors where stabilization of parallel vacancy and interstitial defects can enable high ionic conductivity. | Sacha Fop; James Dawson; Dylan Tawse; Matthew Skellern; Jan Skakle; Abbie Mclaughlin | Materials Science; Energy; Ceramics; Fuel Cells; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-03-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62277d12daa4fbfa0d8418d6/original/proton-and-oxide-ion-conductivity-in-palmierite-oxides.pdf |
659742b5e9ebbb4db9736594 | 10.26434/chemrxiv-2024-z0hg7 | Covalent Triazine-based Frameworks with Covalently Anchored Ru-tda based Catalyst for Photoinduced Water Oxidation | Light-induced water splitting (hv-WS) for the production of hydrogen as a solar fuel is considered a promising sustainable strategy for the replacement of fossil fuels. An efficient system for hv-WS involves a photoactive material that, upon shining light, is capable of separating and transferring charges to catalysts for the hydrogen and oxygen evolution processes. Covalent triazine-based frameworks (CTFs) represent an interesting class of 2D organic light-absorbing materials that have recently emerged thanks to their tunable structural, optical and morphological properties. Typically, catalysts (Cat) are metallic nanoparticles generated in situ after photoelectroreduction of metal precursors or directly drop-casted on top of the CTF material to generate Cat-CTF assemblies. In this work, we report the synthesis, characterization and photocatalytic performance of a novel hybrid material, Ru-CTF, based on a CTF structure featuring dangling pyridyl groups that allow to covalently bond to a Ru-tda (tda is [2,2':6',2''-terpyridine]-6,6''-dicarboxylic acid) water oxidation catalyst (WOC) unit. The Ru-CTF molecular hybrid material can carry out the light-induced water oxidation reaction very efficiently at neutral pH, reaching values of maximum TOF of 17 h-1 and TONs in the range of 220 using sodium persulfate as a sacrificial electron acceptor and in the absence of Ag. The present molecular hybrid system based on organic light-absorbers, constitutes a low cost and sustainable alternative to metal-based inorganic semiconductors generally containing expensive and/or critical metals. | Martina Salati; Florian Dorchies; Jia-Wei Wang; Marta Ventosa; Soranyel González-Carrero; Carlota Bozal-Ginesta; Jan Holub; Olaf Rüdiger; Serena DeBeer; Carolina Gimbert-Suriñach; James R. Durrant; Mehmed Z. Ertem; Marcos Gil-Sepulcre; Antoni Llobet | Inorganic Chemistry; Catalysis; Energy; Heterogeneous Catalysis; Photocatalysis; Redox Catalysis | CC BY 4.0 | CHEMRXIV | 2024-01-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/659742b5e9ebbb4db9736594/original/covalent-triazine-based-frameworks-with-covalently-anchored-ru-tda-based-catalyst-for-photoinduced-water-oxidation.pdf |
66616653418a5379b032d6f6 | 10.26434/chemrxiv-2024-82sbf-v2 | Optimal control-based solid-state NMR cross-polarization between anisotropic nuclear spins | Cross-polarization (CP) is an indispensable part of solid-state nuclear magnetic resonance (NMR) spectroscopy to enhance sensitivity and extract quantitative structural information. However, the most common versions of the CP experiments are susceptible to the presence of anisotropic interactions, including chemical shift anisotropy (CSA) and quadrupolar coupling (QC). Numerous materials and pharmaceutical compounds commonly contain isotopes, such as 19F with large CSA and 6/7Li, 23Na, 27Al, etc., with QC. Inter-nuclear spin correlation experiments can provide crucial local structural information using an efficient cross-polarization method. We introduce a new Optimal Control (OC) simulation generated pulse sequence for Optimal Polarization Transfer In Anisotropic Nuclear Spins (OPTIANS) aiming at 19F-7Li correlations essential for characterizing materials for batteries, heterogeneous catalysis, and many other applications. Numerical simulations showing an improved efficiency for 19F-7Li, 19F-23Na, 19F-27Al and 19F-13C polarization transfer compared to the standard CP are shown. Moreover, robustness against variations in the experimental parameters and the strength of the internal anisotropic interactions is demonstrated using simulations for 19F-7Li case. 19F-7Li polarization transfer experiments on a multi-metal fluoride (MMF) system validate the predictions of the simulations. A comparison with the standard CP experiment shows a gain of 50% in polarization transfer efficiency in the presence of large anisotropic spin interactions at 14.1 T. | Shovik Ray; Venkata S. Redrouthu; Asif Equbal; Sheetal Jain | Physical Chemistry; Materials Science; Physical and Chemical Properties; Spectroscopy (Physical Chem.) | CC BY 4.0 | CHEMRXIV | 2024-06-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66616653418a5379b032d6f6/original/optimal-control-based-solid-state-nmr-cross-polarization-between-anisotropic-nuclear-spins.pdf |
637535a5e70b0a240d9f95bd | 10.26434/chemrxiv-2022-776cb-v3 | Photoactive p-type spinel CuGa2O4 nanocrystals | Herein we report the synthesis and characterization of spinel copper gallate (CuGa2O4) nanocrystals (NCs) with an average size of 3.7 nm via a heat-up colloidal reaction. CuGa2O4 NCs have a band gap of ~2.5 eV and strong p-type character, in agreement with ab initio simulations. These novel NCs are demonstrated to be photoactive, generating a clear and reproducible photocurrent under blue light irradiation when deposited as thin films. Crucially, the ability to adjust the Cu:Ga ratio within the NCs, and its effect on the optical and electronic properties of the NCs was also demonstrated. These results position CuGa2O4 NCs as a novel material for optoelectronic applications, including hole transport and light harvesting. | Owen Kendall; Lesly Melendez-Correa; Jiawen Ren; Samantha Ratnayake; Billy Murdoch; Edwin Mayes; Joel van Embden; Daniel Gomez; Arrigo Calzolari; Enrico Della Gaspera | Nanoscience; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-11-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/637535a5e70b0a240d9f95bd/original/photoactive-p-type-spinel-cu-ga2o4-nanocrystals.pdf |
6581a5a99138d231610ae089 | 10.26434/chemrxiv-2023-qdgj9 | Process Development and Manufacture of the Core Starting Material of Adagrasib (MRTX849) | The beta-ketoester 1 is one of the critical starting materials used in the second-generation synthesis of adagrasib. Disclosed within is a new, streamlined, operationally simple and more environmentally friendly three-step telescoped protocol which was demonstrated on a >100 kg batch with an overall yield of 70%. Identification of the shortcomings and the quality issues of the initial route are discussed. The process development work overcoming these challenges and leading to the new route of synthesis is described. | Thomas Scattolin; Dinesh Paymode; David Snead; Zhichao Lu; Stanley Yu; Maxime Robert-Monpate; Maria Noelia Chao; Thomas Haas; Hanhui Wang; Xuewei Liang; Cheng-yi Chen | Organic Chemistry; Chemical Engineering and Industrial Chemistry; Process Chemistry; Pharmaceutical Industry | CC BY NC 4.0 | CHEMRXIV | 2023-12-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6581a5a99138d231610ae089/original/process-development-and-manufacture-of-the-core-starting-material-of-adagrasib-mrtx849.pdf |
63ea00621d2d1840636905f3 | 10.26434/chemrxiv-2023-k4mzz | Solvation structure of conjugated organosulfur polymers for lithium-sulfur battery cathodes | Lithium-sulfur (Li/S) batteries constitute a promising, next-generation energy storage technology due to their high theoretical energy density and low cost. To increase sustainability, processability, and battery performance, conducting organic polymers have become a focus of research for the development of better cathode materials. Here, we investigate the solvation structure of the conjugated poly(4-thiophen-3-yl) benzenethiol) (PTBT) polymer as a high-potential macromolecular candidate for cathodes in Li/S batteries. Using molecular dynamics (MD) simulation with newly optimized force-field parameters, we examine the effects of polymer length and various molar fractions of the popular dimethoxyethane (DME) and dioxolane (DOL) solvents on the structure of the PTBT polymer at a temperature of 300 K. We characterize basic polymeric properties as well as the composition-dependent solvent adsorption structure and thermodynamics. Importantly, we find an interesting co-solvency effect, namely that a solvent comprised of about 25% DME and 75% DOL leads to maximum swelling (best solvent quality) behavior, which should be important for optimizing cathode fractality and permeability in applications. Our study thus reveals intriguing polymer-solvent correlations and serves as a first step for further MD studies of realistic polymeric cathode structures and processes, e.g., toward charge transport in vulcanized (S-linked) network topologies. | Diptesh Gayen; Yannik Schütze; Sebastien Groh; Joachim Dzubiella | Theoretical and Computational Chemistry; Polymer Science; Energy; Conducting polymers; Theory - Computational; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2023-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63ea00621d2d1840636905f3/original/solvation-structure-of-conjugated-organosulfur-polymers-for-lithium-sulfur-battery-cathodes.pdf |
6728e1d25a82cea2fa012fc8 | 10.26434/chemrxiv-2024-kcjhb | Metabolomics to Assess Treatment Responses to a Single Large Bolus of Enteral Cholecalciferol in Vitamin D Deficient Critically Ill Children: Insights for Precision Nutrition | Vitamin D deficiency (VDD) is prevalent globally and in pediatric intensive care units, where it represents a modifiable risk factor that may impact patient recovery during hospitalization. However, few studies have investigated the dynamic metabolic effects from a single large bolus of enteral cholecalciferol to rapidly restore vitamin D status in critically ill children. Herein, we performed a retrospective analysis of serum samples collected from the VITdALIZE-KIDS pilot study, a phase-II randomized placebo-controlled trial, to elucidate treatment response variations following the intake of 10,000 IU/kg vitamin D3 (up to a maximum of 400,000 IU or 10 mg) by critically ill children with VDD (25-OH-D < 50 nmol/L). Comprehensive vitamin D metabolite and lipidomic studies were performed by reversed-phase ultra-high performance liquid chromatography-mass spectrometry, whereas serum metabolomics and a targeted electrolyte panel were acquired by multisegment injection-capillary electrophoresis-mass spectrometry and capillary electrophoresis with indirect UV detection, respectively. Overall, 6 vitamin D species, 239 lipids, 68 metabolites and 4 electrolytes were measured in most serum samples (> 70%) with adequate precision (CV < 40%) from pooled quality control samples using a multi-step data workflow for molecular feature selection and metabolite authentication. Complementary statistical methods were used to classify circulating metabolites/lipids associated with treatment induced vitamin D sufficiency on day 7 (25-OH-D > 75 nmol/L) following high-dose vitamin D3 intake (n=20) or placebo (n=11) who received a daily maintenance of vitamin D3 (< 1000 IU/day). There was a striking increase in median serum concentrations of 25-OH-D3 (4.7-fold, p = 2.39 x 10-8), 3-epi-25-OH-D3 (24-fold, p = 8.27 x 10-10) and their C3-epimer ratio (6.7-fold, p = 6.22 x 10-5) in treated patients on day 3, whereas serum vitamin D3 levels peaked on day 1 (128-fold, p = 9.11 x 10-8) relative to the standard-of-care. Treatment response differences were largely attributed to differences in oral D3 bioavailability and C3-epimerase activity, but not 25-hydroxylation activity nor baseline calcium or magnesium status. Also, two treated participants were identified as poor responders likely due to malabsorption, and there was no evidence of hypercalcemia in this study. For the first time, we report the detection of circulating 3-epi-D3 that was strongly correlated with vitamin D3 uptake (r = 0.898, p = 3.27 x 10-53), however, its C3-epimer ratio did not change when compared to the daily maintenance therapy as placebo. The systemic metabolic effects of vitamin D sufficiency (serum 25-OH-D > 75 nmol/L on days 2 or 3) corresponded to lower circulating levels of 3-methylhistidine, cystine, S-methylcysteine, uric acid, and two lysophosphatidylcholines (LPC 20:0; LPC 20:2) measured after 7 days with covariate adjustments (p < 0.05; age, sex, weight, and season) relative to vitamin D insufficient patients (serum 25-OH-D < 75 nmol/L). The former three polar metabolites were also significant after adjusting for baseline 25-OH-D status. Overall, serum cystine trajectories were the most sensitive indicator of vitamin D repletion after the first week. Rapid correction of VDD was associated with a metabolic phenotype associated with lower oxidative stress, inflammation, and muscle protein turn-over that may impart clinical benefits. | Erick Helmeczi; Haley Pandya; Katie O’Hearn; Dayre McNally; Philip Britz-Mckibbin | Analytical Chemistry; Biochemical Analysis; Mass Spectrometry; Separation Science | CC BY NC 4.0 | CHEMRXIV | 2024-11-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6728e1d25a82cea2fa012fc8/original/metabolomics-to-assess-treatment-responses-to-a-single-large-bolus-of-enteral-cholecalciferol-in-vitamin-d-deficient-critically-ill-children-insights-for-precision-nutrition.pdf |
60c74af40f50db3836396b4e | 10.26434/chemrxiv.12275741.v1 | Ro5 Bioactivity Lab: Identification of Drug Candidates for COVID-19 | The public health emergency known as the coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a large number of deaths worldwide and major socioeconomic disruption. To date, no broadly effective antiviral treatment or vaccine has been developed for COVID-19. In response to this dire situation, Ro5 deployed its AI Lab to accelerate the search for potential treatments. This report focuses on our use of the Ro5 Bioactivity model, which has been designed to predict the inhibitory activity of small molecules against protein targets. The model screened a vast range of compounds <i>in silico</i> to uncover potential inhibitors of the SARS-CoV-2 3CL protease. We hereby present the most propitious candidates from this screen. The highest-ranking molecules include Nelfinavir, Saquinavir, Itacitinib, Kynostatin-272, BOG-INS-6c2-1, and BEN-VAN-d2b-11. Subsequent docking simulations corroborate their plausibility as 3CLpro inhibitors. Nelfinavir and Itacitinib hold the most promise for drug repurposing, among all the molecules proposed herein, due to their high predicted inhibition and affinity against the 3CL protease, favourable pharmacokinetics, and encouraging experimental data for treating viral replication and hyperinflammation, respectively. | Zeyu Yang; Orestis Bastas; Mikhail Demtchenko; Aurimas Pabrinkis; Cooper Stergis Jamieson; Danius Bačkis; Charles Dazler Knuff; Žygimantas Jočys; Roy Tal | Biochemistry; Bioinformatics and Computational Biology; Drug Discovery and Drug Delivery Systems; Computational Chemistry and Modeling; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74af40f50db3836396b4e/original/ro5-bioactivity-lab-identification-of-drug-candidates-for-covid-19.pdf |
60c74128469df4460cf42dc7 | 10.26434/chemrxiv.7982864.v1 | Bringing Biocatalysis into the Deuteration Toolbox | <p></p><p>Chemicals labelled with the heavy hydrogen isotope
deuterium (<sup>2</sup>H) have long been used in chemical and biochemical
mechanistic studies, spectroscopy, and as analytical tracers. More recently, demonstration
of selectively deuterated drug candidates that exhibit advantageous pharmacological
traits has spurred innovations in metal-catalysed <sup>2</sup>H insertion at
targeted sites, but asymmetric deuteration remains a key challenge. Here we
demonstrate an easy-to-implement biocatalytic deuteration strategy, achieving
high chemo-, enantio- and isotopic selectivity, requiring only <sup>2</sup>H<sub>2</sub>O
(D<sub>2</sub>O) and unlabelled dihydrogen under ambient conditions. The vast
library of enzymes established for NADH-dependent C=O, C=C, and C=N bond
reductions have yet to appear in the toolbox of commonly employed <sup>2</sup>H-labelling
techniques due to requirements for suitable deuterated reducing equivalents. By
facilitating transfer of deuterium atoms from <sup>2</sup>H<sub>2</sub>O
solvent to NAD<sup>+</sup>, with H<sub>2</sub> gas as a clean reductant, we
open up biocatalysis for asymmetric reductive deuteration as part of a
synthetic pathway or in late stage functionalisation. We demonstrate
enantioselective deuteration via ketone and alkene reductions and reductive
amination, as well as exquisite chemo-control for deuteration of compounds with
multiple unsaturated sites.</p><p></p> | Jack Rowbotham; Oliver Lenz; Holly Reeve; Kylie Vincent | Drug Discovery and Drug Delivery Systems; Biocatalysis; Heterogeneous Catalysis; Redox Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2019-04-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74128469df4460cf42dc7/original/bringing-biocatalysis-into-the-deuteration-toolbox.pdf |
6151853739ef6a61f82baeac | 10.26434/chemrxiv-2021-dzzmj | The Flexible Microtube Plasma as Post-Ionization Source for Cholesterol in nano-Electrospray Mass Spectrometry | Cholesterol serves as a biomarker in clinical- and life-sciences. The determination of abnormal levels can indicate several types of human diseases. However, the low polarity of free cholesterol makes it hardly accessible by (nano) electrospray ionization mass spectrometry (nESI-MS). As novel approach, the flexible microtube plasma (FμTP) for post-ionization allows the determination of low-polar compounds like cholesterol in combination with nESI-MS. Focusing on the analytical performance, the activated post-ionization leads to an increased cholesterol signal by a factor of 22. The repeatability and long-term stability could be successful evaluated by using a complex liver extract. Via the method of standard addition, a linear dynamic range of 1.7 orders of magnitude, a minimum detectability of 3.71 mg/L and a high accuracy (deviation: − 8.11 %) is demonstrated proofing the FμTP-nESI-MS as an excellent approach for a derivatization-free determination of cholesterol without the necessity of high-resolution Orbitrap devices or enhanced MS acquisition-methods. | Daniel Foest; Alexander Knodel; Robert Ahrends; Cristina Coman; Joachim Franzke; Sebastian Brandt | Biological and Medicinal Chemistry; Analytical Chemistry; Analytical Apparatus; Biochemical Analysis; Mass Spectrometry | CC BY NC ND 4.0 | CHEMRXIV | 2021-09-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6151853739ef6a61f82baeac/original/the-flexible-microtube-plasma-as-post-ionization-source-for-cholesterol-in-nano-electrospray-mass-spectrometry.pdf |
646bee6ab3dd6a653091c1ca | 10.26434/chemrxiv-2023-pp192 | The Role of Entropy on the Electrochemistry of Entropy-Stabilized Oxides and Their Lithium Storage Mechanism | Micrometer-size particles of entropy-stabilized transition metal-based high entropy oxide, (MgCoNiCuZn)O, has demonstrated long-term cycling stability against lithium-ion battery, a feat that has only been achieved with nanometer-size transition metal binary oxides. This electrochemical performance has been attributed to the entropy stabilization effect observed in this material. This work demonstrates that entropy stabilization might not play a role in the electrochemical performance of this compound as previously suggested, by comparing the electrochemical data of two medium entropy materials, (MgNiCuZn)O and (CoNiCuZn)O, with that of the high entropy material. In addition, the mechanism of lithium interaction with these materials is still poorly understood, in part owing to the difficulties in characterizing structure at the nanoscale. Solid-state operando NMR/derivative operando techniques are used to demonstrate that the lithiation of these compounds proceeds via a partially reversible conversion-type reaction involving the reduction of the transition metals cations to their metallic form during lithiation and the oxidation of these individual metal particles to their oxides form, losing the initial single-phase compound after the first lithiation cycle. The NMR results also show that the conductive carbon black used as an electronic conductor can store a significant amount of charge at low voltage, indicating that it is a major contributor to the additional observed in these entropy-stabilized oxides and in transition metal salts. | Modeste Tegomoh; Jose Lorie Lopez; Zhihao Cui; Philip Grandinetti; Anne Co | Materials Science; Energy; Energy Storage; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-05-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/646bee6ab3dd6a653091c1ca/original/the-role-of-entropy-on-the-electrochemistry-of-entropy-stabilized-oxides-and-their-lithium-storage-mechanism.pdf |
6695654ec9c6a5c07a5e940e | 10.26434/chemrxiv-2024-rt918 | Fuelling A Clean Future: A Systematic Review of Techno-Economic and Life Cycle Assessments in E-Fuel Development | The transition towards sustainable energy sources has ushered in the era of electrofuels or synthetic fuels (e-fuels), which are produced/synthesised with electricity from renewable sources, water, and CO2, and are a sustainable alternative to fossil fuels. This paper presents a systematic review of the techno-economic (TEA) and life cycle assessments (LCA) pertaining to e-fuel production. We critically evaluate the advancements in production technologies, economic feasibility, environmental implications, and potential societal impacts. Our findings indicate that while e-fuels offer a promising solution to reduce carbon emissions, their economic viability remains contingent on the optimization of production processes and the cost of input materials. The LCA underlines the importance of sourcing renewable energy for hydrogen production to ensure genuine sustainability of e-fuels. The review further identifies knowledge gaps, recommending areas for future research and policy intervention for e-fuels. As the world steers towards a greener future, understanding the holistic implications of e-fuels becomes paramount, and this review aims to provide a comprehensive overview to guide stakeholders in their decision-making processes. | M.N. Uddin; Feng Wang | Energy; Chemical Engineering and Industrial Chemistry; Petrochemicals; Energy Storage; Fuels - Energy Science; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-07-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6695654ec9c6a5c07a5e940e/original/fuelling-a-clean-future-a-systematic-review-of-techno-economic-and-life-cycle-assessments-in-e-fuel-development.pdf |
64f070fcdd1a73847fe1e9c6 | 10.26434/chemrxiv-2023-fqdts | IPLOT-VKA: an Integral-method Powell-pLOT-enhanced Visual Kinetic Analysis for the determination of orders of reaction | Determination of partial orders in kinetics is a general entry step for any mechanistic investigation; recently, considerable attention has been given to the benefits of using visual methods to help in this task, such as easy utilization and data-efficiency. Here, the classic method by Powell and Margerison has been revisited and improved adding new features (e.g. quantitative estimation of errors), the set of analytical working equation has been widened, and a free, open-access and easy-to-use Web-application, named IPLOT-VKA has been developed. Several examples, taken from reference teaching experiences and from recent literature in catalysis show the efficacy and accuracy of our method. | Alessandro Landi; Guglielmo Monaco | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Chemical Kinetics | CC BY NC ND 4.0 | CHEMRXIV | 2023-09-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64f070fcdd1a73847fe1e9c6/original/iplot-vka-an-integral-method-powell-p-lot-enhanced-visual-kinetic-analysis-for-the-determination-of-orders-of-reaction.pdf |
60c7449b337d6c120ee26e1b | 10.26434/chemrxiv.9862745.v1 | The Crystal Structure of Zineb, 75 years later | Ethylene bis(dithiocarbamates) (EBDTCs) have been used as staple fungicides for over 75 years. The first industrially manufactured EBDTC was zineb, zinc ethylene bis(dithiocarbamate), marketed under the tradename Dithane. Even though zineb has been used as a fungicide since the 1940s, its crystal structure remained unknown. Herein, we describe the crystal structure of zineb (triclinic crystal system, space group P–1, a = 7.5094(9) Å, b = 9.4356(9) Å, c = 7.4120(7) Å, α = 107.945(8) °, β = 100.989(7) °, γ = 105.365(8) °, V = 460.07(10) Å3). The inorganic fragment of the structure consists of two Zn2+ cations, coordinated by the thiocarbamate group. There are four Zn–S bonds with lengths in the range of 2.325 – 2.426 Å, and one rather long Zn–S contact of 2.925(8) Å. Inorganic fragments are linked by organic EBDTC ligands to form extended, polymeric layers. The layers are packed in a ABAB manner, related by the inversion symmetry and held together by hydrogen bonding network. In this article, in addition to describing the crystal structure, we correlate the structural features with the vibrational spectroscopic and thermal characteristics of zineb, and we provide a short summary of the major developments of fungicides in the 20th century<br /> | Jonathan B Lefton; Kyle B Pekar; Tomce Runcevski | Hybrid Organic-Inorganic Materials; Feed | CC BY NC ND 4.0 | CHEMRXIV | 2019-09-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7449b337d6c120ee26e1b/original/the-crystal-structure-of-zineb-75-years-later.pdf |
6490b93ba2c387fa9a94f607 | 10.26434/chemrxiv-2023-kcrnm | Adaptive restraints to accelerate geometry optimizations of large biomolecular systems | Quantum mechanical/molecular mechanical geometry optimizations of large-scale biological sys- tems, such as enzymes, proteins, membranes and solutions are typically computationally expensive to the point of being cost-prohibitive. By convention, an approximation is made to such calculations that atoms beyond a certain distance from the QM region provide only negligible improvements to the resulting optimization energy and geometry, and as such are restrained to reduce the number of degrees of freedom. These constraints are normally applied beyond a user-defined radius. Here we describe a new method of geometry optimization acceleration which generates adaptive gradient-based restraints for QM/MM optimizations, leading to faster optimizations and generally lower energies which signify a "better" optimized geometry. The restraints are de- termined by an algorithm rather than a user, and can adapt to directional optimizations as well as differences in starting geometry. This algorithm was implemented as an external python tool for use alongside TeraChem, with a modular interface that can be straightforwardly applied to other QM/MM packages. We tested on a green fluorescent protein (rsEGFP2) in water and a proton-swapping aspartic acid pair in explicit water. We are able to produce a nearly 50% reduction of computational time with a corresponding decrease in optimized energies of ∼-0.4 a.u. with optimal parameters. | Mark A. Hix; Alice R. Walker | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6490b93ba2c387fa9a94f607/original/adaptive-restraints-to-accelerate-geometry-optimizations-of-large-biomolecular-systems.pdf |
632907f6cf38299c46aa8788 | 10.26434/chemrxiv-2022-g1h5x | Nanostructure-derived anti-reflectivity in leafhopper brochosomes | Understanding how insect-derived biomaterials interact with light has led to new advances and interdisciplinary insights in entomology and physics. Leafhoppers are insects that coat themselves with highly ordered biological nanostructures known as brochosomes. Brochosomes are thought to provide a range of protective properties to leafhoppers, such as hydrophobicity and anti-reflectivity, which has inspired the development of synthetic brochosomes that mimic their structures. Despite recent progress, the ultra-high anti-reflective properties of brochosome structures are not fully understood. In this work, we use a combination of experiments and computational modeling to understand the structure-, material-, and polarization-dependent optical properties of brochosomes modeled on the geometries found in three leafhopper species. Our results show that that Fano resonance is responsible for the ultra-high anti-reflectivity of brochosomes. Whereas prior work has focused on computational modeling of idealized pitted particles, our work shows that light-matter interactions with brochosome structures can be tuned by varying the geometry of their cage-like nanoscale features and by changing the arrangement of multi-particle assemblies. Broadly, this work establishes principles for the guided design of new optically active materials inspired by these unique insect nanostructures. | Progna Banerjee; Gabriel Burks; Sarah Bialik; Mostafa Nassr; Elizabeth Bello; Marianne Alleyne; Benny Freeman; Jeffrey Barrick; Charles Schroeder; Delia Milliron | Materials Science; Nanoscience; Biological Materials; Coating Materials; Plasmonic and Photonic Structures and Devices | CC BY NC ND 4.0 | CHEMRXIV | 2022-09-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/632907f6cf38299c46aa8788/original/nanostructure-derived-anti-reflectivity-in-leafhopper-brochosomes.pdf |
679033df81d2151a02397b53 | 10.26434/chemrxiv-2025-dnzfr-v2 | Controlled/"Living" Click Polymerization with Possible Bi-Directional Chain-Growth Propagation during Polyaddition | In this work, we found a new class of controlled/"living" polymerization system, which proceeds bidirectional fashion using click reaction of AB monomer bearing azide and alkyne functionalities in a single molecule. The click polymerization of the AB monomer proceeded well using both azide and alkyne initiators in a well-controlled manner in either growth direction to afford polymers with predetermined molecular weights and narrow molecular weight distributions as well as the terminal structures inherited from the initiator. Especially, the polymerizations with the difunctional initiators provided well-defined linear polymers with azide or alkyne groups at both termini. This approach also allows for polymerization control over the second monomer to give a block copolymer. | Satoshi Sakai; Takuya Nakamura; Mineto Uchiyama; Tomohiro Kubo; Masami Kamigaito; Kotaro Satoh | Polymer Science; Polymerization (Polymers) | CC BY NC ND 4.0 | CHEMRXIV | 2025-01-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/679033df81d2151a02397b53/original/controlled-living-click-polymerization-with-possible-bi-directional-chain-growth-propagation-during-polyaddition.pdf |
629e3c3380f81c16d29e681a | 10.26434/chemrxiv-2022-3jx39-v2 | The defective nature of CdSe quantum dots embedded in inorganic matrices | Quantum dots (QDs) embedded in inorganic matrices have been extensively studied for their potential applications in lighting, displays, and solar cells. While a significant amount of research focused on its experimental fabrication, the origin of their relatively low photoluminescence quantum yield has not been investigated yet, although it severely hinders practical applications. In this work, we use time-dependent density functional theory (TDDFT) to pinpoint the nature of excited states of CdSe quantum dots embedded in various inorganic matrices. The formation of undercoordinated Se atoms and non-bridging oxygen atoms at QD/glass interface is responsible for the localization of a hole wavefunction, leading to the formation of low- energy excited states with weak oscillator strength. These states provide pathways for non-radiative processes and compete with radiative emission. The photoluminescence performance is predicted for CdSe quantum dots in different matrices, and validated by experiments. The results of this work have significant implications for understanding the underlying photophysics of CdSe quantum dots embedded in inorganic matrices that would facilitate the fabrication of highly luminescent glasses. | Wenke Li; Kai Li; Xiujian Zhao; Chao Liu; François-Xavier Coudert | Theoretical and Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-06-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/629e3c3380f81c16d29e681a/original/the-defective-nature-of-cd-se-quantum-dots-embedded-in-inorganic-matrices.pdf |
60c7497a702a9bbedf18b147 | 10.26434/chemrxiv.12044586.v1 | Increasing the Functional Group Diversity in Helical β-Peptoids: Achievement of Solvent- and pH-Dependent Folding | We report the synthesis of a series of bis-functionalized <i>b</i>-peptoid oligomers of the hexamer length. This was achieved by synthesizing and incorporating protected amino- or azido-functionalized chiral building blocks into precursor oligomers by a trimer segment coupling strategy. The resulting hexamers were readily elaborated to provide target compounds displaying amino groups, carboxy groups, hydroxy groups, or triazolo-pyridines, which should enable metal ion binding. Analysis of the novel hexamers by CD spectroscopy and HSQC NMR spectroscopy revealed robust helical folding propensity in acetonitrile. CD analysis showed solvent-dependent degree of helical content in the structural ensembles when adding different ratios of protic solvents including aqueous buffer. These studies were enabled by the substantial increase in solubility compared to previously analyzed <i>b</i>-peptoid oligomers. This also allowed for investigation of the effect of pH on folding propensity of the amino- and carboxy-functionalized oligomers, respectively. Interestingly, we could demonstrate a reversible effect of sequentially adding acid and base, resulting in a switching between compositions of folded ensembles with varying helical content. We envision that the present discoveries can form the basis for the development of functional peptidomimetic materials responsive to external stimuli. | Isabelle Wellhöfer; Janina Beck; Karla Frydenvang; Stefan Bräse; Christian Adam Olsen | Bioorganic Chemistry; Biochemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7497a702a9bbedf18b147/original/increasing-the-functional-group-diversity-in-helical-peptoids-achievement-of-solvent-and-p-h-dependent-folding.pdf |
641998d4aad2a62ca11b56c3 | 10.26434/chemrxiv-2023-f7dkw | Desiccation Patterns of Particle Laden Salt Droplets | Drying of complex fluids leads to the formation of several intricate patterns where each component plays a unique role in determining the final dried morphologies. Salts are essential to body fluids (viz. blood, urine, saliva) and buffer solutions. Hence, understanding the sole effect of salts on the dried patterns of complex fluids has become imperative. In the present investigation, the exclusive effects of some commonly available salts on the final dried patterns of model solutions in the presence of polystyrene particles have been explored. Fascinating results have been observed as the sole presence of salts was found to alter the final dried patterns of the particle suspensions. To delve deeper into the physics of evaporation dynamics, a qualitative analysis has also been undertaken to estimate the predominant forces affecting the dried droplet morphologies. This investigation can serve as a baseline for understanding the underlying mechanisms involved during the drying of complex fluids to further aid in disease diagnosis. | Manikuntala Mukhopadhyay; Sri Ganesh Subramanian; Anashwara Nair; Debasish Sarkar; Sunando DasGupta | Physical Chemistry; Analytical Chemistry; Chemical Engineering and Industrial Chemistry; Interfaces; Self-Assembly; Transport phenomena (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/641998d4aad2a62ca11b56c3/original/desiccation-patterns-of-particle-laden-salt-droplets.pdf |
6231f237202c06445dd5e660 | 10.26434/chemrxiv-2022-dgkf5 | In-Situ Observation of the Structure of Crystallising Magnesium Sulfate Heptahydrate Solutions with Terahertz Transmission Spectroscopy |
Terahertz time-domain spectroscopy in a transmission geometry combined with vi- sual analysis was used to investigate the crystallisation process of MgSO4 solution. Careful spectral analysis of both a feature at 1.6 THz and the baseline allowed the ex- traction of information about the liquid phase before and during crystallisation, aiding the investigation of solvation dynamics and the behaviour of molecular species at phase boundaries. The method was reproducibly applied to a number of measurements on a series of solutions of three chosen concentrations at different temperatures. When increasing temperature at the end of the measurement, the dissolution of crystals was observed as well. The temperature-dependent absorption data of the semi-crystalline systems were converted to the solvent concentrations using a recently developed method. Solutions of a series concentrations were also investigated in the temperature range of 4◦C to 25◦C. The results were compared to the theoretical calculated values, and the consistent differences proved the existence of a hydration shell around the salt ions whose behaviour is different from bulk water. Future work will focus on triggering nucleation at specific positions in order to study the very beginning of the crystallisa- tion process. MgSO4 heptahydrate is used as a model system in this study, while the concept and the set-up can be applied to other systems. | Qi Li; Johanna Kölbel; Margaret P. Davis; Timothy M. Korter; Andrew D. Bond; Terrence L. Threlfall; J. Axel Zeitler | Physical Chemistry; Analytical Chemistry; Chemical Engineering and Industrial Chemistry; Reaction Engineering; Physical and Chemical Processes; Crystallography | CC BY 4.0 | CHEMRXIV | 2022-03-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6231f237202c06445dd5e660/original/in-situ-observation-of-the-structure-of-crystallising-magnesium-sulfate-heptahydrate-solutions-with-terahertz-transmission-spectroscopy.pdf |
649c05c86e1c4c986b7a5753 | 10.26434/chemrxiv-2023-0fx93 | Vertical flow immunoassay based on carbon black nanoparticles for the detection of IgG against SARS-CoV-2 Spike-protein in human serum: proof-of-concept | Point-of-care tests play an important role in serological diagnostics of infectious diseases and post-vaccination immunity monitoring, including COVID-19. Currently, lateral flow tests dominate in this area and show good analytical performance. However, studies to improve the effectiveness of such tests remain important. In comparison with lateral flow tests, vertical flow immunoassays allow for a reduction in assay duration and the influence of the hook effect. Additionally, the use of carbon black nanoparticles (CNP) as a color label can provide a lower detection limit (LOD) compared to conventional colloidal gold. Therefore, we have developed a vertical flow immunoassay for the detection of IgG against SARS-CoV-2 Spike-protein in human serum samples by applying a conjugate of CNP with anti-human IgG mouse monoclonal antibodies (CNP@MAb). The vertical flow assay device consists of a plastic cassette with a hole on its top containing a nitrocellulose membrane coated with Spike-protein and an absorbent pad. The serum sample, washing buffer, and CNP@MAb flow vertically through the nitrocellulose membrane and absorbent pads, reducing the assay time and simplifying the procedure. In positive samples, the interaction of CNP@MAb with anti-spike antibodies leads to the appearance of black spots, which can be visually detected. The developed method allows for rapid visual detection (5-7 minutes) of IgG vs Spike-protein with a LOD of 7.81 BAU/mL. It has been shown that an untrained operator can perform the assay and visually evaluate its results. Thus, the presented assay can be used in the further development of test systems for the serological diagnostics of COVID-19 or post-vaccination immunity monitoring. | Mariya Kropaneva; Pavel Khramtsov; Mariya Bochkova; Sergey Lazarev; Dmitriy Kiselkov; Mikhail Rayev | Biological and Medicinal Chemistry; Nanoscience | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/649c05c86e1c4c986b7a5753/original/vertical-flow-immunoassay-based-on-carbon-black-nanoparticles-for-the-detection-of-ig-g-against-sars-co-v-2-spike-protein-in-human-serum-proof-of-concept.pdf |
673e88bdf9980725cf203ce5 | 10.26434/chemrxiv-2024-smxcc-v2 | Advancing the Mechanosensitivity of Atropisomeric Diarylethene Mechanophores Through a Lever-Arm Effect | Understanding structure-mechanical activity relationships (SMARs) in polymer mechanochemistry is essential for the rational design of mechanophores with desired properties, yet SMARs in noncovalent mechanical transformations remain relatively underexplored. In this study, we designed a subset of diarylethene mechanophores based on a lever-arm hypothesis and systematically investigated their mechanical activity toward a noncovalent-yet-chemical conversion of atro-pisomer stereochemistry. Results from DFT calculations, single-molecule force spectroscopy (SMFS) measurements, and ultrasonication experiments collectively support the lever-arm hypothesis and confirm the exceptional sensitivity of chemo-mechanical coupling in these atropisomers. Notably, the transition force for the diarylethene M3 featuring extended 5-phenylbenzo[b]thiophene aryl groups is determined to be 131 pN ± 4 pN by SMFS. This value is lower than typically recorded for other mechanically induced chemical processes, highlighting its exceptional sensitivity to low-magnitude forces. This work contributes a fundamental understanding of chemo-mechanical coupling in atropisomeric configurational mechanophores and paves the way for designing highly sensitive mechanochemical processes that could facilitate the study of nanoscale mechanical behaviors across scientific disciplines. | Cijun Zhang; Tatiana B. Kouznetsova; Boyu Zhu; Liam Sweeney; Max Lancer; Ivan Gitsov; Stephen L. Craig; Xiaoran Hu | Organic Chemistry; Materials Science; Polymer Science | CC BY 4.0 | CHEMRXIV | 2024-11-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/673e88bdf9980725cf203ce5/original/advancing-the-mechanosensitivity-of-atropisomeric-diarylethene-mechanophores-through-a-lever-arm-effect.pdf |
65c53baf9138d23161b505b7 | 10.26434/chemrxiv-2024-djx7b | C(sp3)–H sulfinylation of light hydrocarbons with sulfur dioxide via hydrogen atom transfer photocatalysis in flow | Sulfur-containing scaffolds originating from small alkyl fragments play a crucial role in various pharmaceuticals, agrochemicals, and materials. Nonetheless, their synthesis using conventional methods presents significant challenges. In this study, we introduce a practical and efficient approach that harnesses hydrogen atom transfer photocatalysis to activate volatile alkanes, such as isobutane, butane, propane, ethane, and methane. Subsequently, these nucleophilic radicals react with SO2 to yield the corresponding sulfinates. These sulfinates then serve as versatile building blocks for the synthesis of diverse sulfur-containing organic compounds, including sulfones, sulfonamides, and sulfonate esters. Our use of flow technology offers a robust, safe and scalable platform for effectively activating these challenging gaseous alkanes, facilitating their transformation into valuable sulfinates. | Dmitrii Nagornîi; Fabian Raymenants; Nikolaos Kaplaneris; Timothy Noel | Organic Chemistry; Catalysis; Chemical Engineering and Industrial Chemistry; Organic Synthesis and Reactions; Homogeneous Catalysis; Photocatalysis | CC BY 4.0 | CHEMRXIV | 2024-02-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65c53baf9138d23161b505b7/original/c-sp3-h-sulfinylation-of-light-hydrocarbons-with-sulfur-dioxide-via-hydrogen-atom-transfer-photocatalysis-in-flow.pdf |
619d4c79a129236d6c4bcb9f | 10.26434/chemrxiv-2021-29rtf | Investigation of Carboxylic Acid Isosteres for Inhibition of the Human SIRT5 Lysine Deacylase Enzyme | Sirtuin 5 (SIRT5) is a protein lysine deacylase enzyme that regulates diverse biology by hydrolyzing -N-carboxyacyllysine posttranslational modifications in the cell. Inhibition of SIRT5 has been linked to potential treatment of several cancers but potent compounds with activity in cells have been lacking. Here we developed mechanism-based inhibitors that incorporate isosteres of a carboxylic acid residue that is important for high-affinity binding to the enzyme active site. By masking of the tetrazole moiety of the most potent candidate from our initial SAR study, we achieved potent and cytoselective growth inhibition for the treatment of SIRT5-dependent leukemic cancer cell lines in culture. Thus, we provide an efficient, cellularly active small molecule that targets SIRT5, which can help elucidate its function and potential as a future drug target. This work shows that masked biosisosteres of carboxylic acids are viable chemical motifs for the development of inhibitors that target mitochondrial enzymes, which may have applications beyond the sirtuin field. | Nima Rajabi; Alexander L. Nielsen; Tobias N. Hansen; Huy T. Nguyen; Michael Bæk; Julie E. Bolding; Oskar Ø. Bahlke; Sylvester E. G. Petersen; Christian R. O. Bartling; Kristian Strømgaard; Christian Adam Olsen | Biological and Medicinal Chemistry; Organic Chemistry; Organic Compounds and Functional Groups; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY NC 4.0 | CHEMRXIV | 2021-11-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/619d4c79a129236d6c4bcb9f/original/investigation-of-carboxylic-acid-isosteres-for-inhibition-of-the-human-sirt5-lysine-deacylase-enzyme.pdf |
67510c765a82cea2fa07c96c | 10.26434/chemrxiv-2024-17kvm | Friedel-Crafts reaction with polyolefins as alkylation reagents and poly(vinyl chloride) as initiator | Transformation of waste plastics into high-value chemicals provides an important solution to mitigate their huge impact on the environment. Polyolefins, including polyethylene and polypropylene, two most produced plastics, are composed of long-chain alkanes and can be potentially applied as alkylation reagents for organic transformations. In this work, we demonstrated that aluminum trichloride in the combination of poly(vinyl chloride), the third most produced and one of the least recycled plastic, can mediate Friedel-Crafts reaction of benzene with polyethylene, polypropylene or the mixture of the two as alkylation reagents. The reaction takes place under mild conditions, selectively producing toluene, ethylbenzene, cumene and n-propylbenzene. As the two major alkylbenzene products, ethylbenzene and cumene, are traditionally produced with ethylene or propene as alkylation reagent, this protocol shows the potential of polyolefins as surrogates for small olefins in organic transformations, offering new opportunities in a sustainable circular economy. | Xinyue Tan; Yizhou Yang; Zhen Hua Li; Huadong Wang | Catalysis; Acid Catalysis | CC BY NC 4.0 | CHEMRXIV | 2024-12-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67510c765a82cea2fa07c96c/original/friedel-crafts-reaction-with-polyolefins-as-alkylation-reagents-and-poly-vinyl-chloride-as-initiator.pdf |
65bcfecc66c1381729d06493 | 10.26434/chemrxiv-2024-16fc3 | Improved protocols for the synthesis of Precursors of Thiazol-2-ylidene N-Heterocyclic Carbenes | We report improved protocols for the synthesis of thiazolium precatalysts from primary amines, carbon disulfide and alpha-halogenoketones. For N-alkyl substituted derivatives, yields for the corresponding thiazolethiones can be dramatically improved when isolating the intermediate dithiocarbamates. In most cases, meta-chloroperbenzoic acid can replace advantageously H202 in acetic acid for the oxidation of thiazolethiones into thiazoliums. This approach was applied to the synthesis of a thiazolium featuring a 2-adamantyl N-substituent, the corresponding persistent carbene and its dimer. | Ludivine Delfau; Jacques Pecaut; Eder Tomás-Mendivil; David Martin | Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65bcfecc66c1381729d06493/original/improved-protocols-for-the-synthesis-of-precursors-of-thiazol-2-ylidene-n-heterocyclic-carbenes.pdf |
60c7580a0f50db46283983a7 | 10.26434/chemrxiv.14493756.v1 | Nickel(II) Salicylaldiminates: Re-Visiting a Classic | A series of Ni(II) trinuclear complexes, [Ni<sub>3</sub>(sala-X)<sub>6</sub>]
(sala-X = <i>o</i>-[(<i>p</i>-X-phenylimino)methyl]phenol; X = Br <b>1-Br</b>,
Me <b>1-Me</b> and OMe <b>1-OMe</b>), have been prepared and fully
characterised. X-ray crystallographic studies reveal that the complexes are
composed of <a>three face-sharing octahedral Ni(II) metal
ions bridged by the phenoxide oxygens of the sala-X ligands</a>. Magnetic
studies indicate that the magnetic Ni(II) centres are ferromagnetically coupled
with the substituent group having only a minor impact on the magnitude of
coupling. DFT calculations also support ferromagnetic coupling with smaller
Ni-O-Ni angles leading to slightly larger coupling constants in line with
previous studies. | Supaporn Saechio; Rodolphe CLERAC; Keith Murray; Wasinee Phonsri; Eliseo Ruiz; Phimphaka Harding; David Harding | Magnetic Materials; Coordination Chemistry (Inorg.); Crystallography | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7580a0f50db46283983a7/original/nickel-ii-salicylaldiminates-re-visiting-a-classic.pdf |
60c7506b702a9b41ce18bd72 | 10.26434/chemrxiv.13032578.v1 | Old Arsenal to Combat New Enemy: Repurposing of Commercially Available FDA Approved Drugs Against Main Protease of SARS-CoV2. | <p>
In
lack of vaccination and therapeutic drugs, the ongoing COVID-19
pandemic affected millions of people, causing 1,018,957 deaths
worldwide (World health organization; 1<sup>st</sup>
October 2020). The conventional drug design pipeline for effective
and safer drug development is a costly and time-intensive affair. It
takes around ten years in general from identifying a clinical
candidate to get the approvals for actual applications. An effective
way to cut short drug design pipeline in such emergency cases could
be the repurposing of already approved drugs against novel targets.
Here in this work, we explored the structure-based drug screening
approach to find potential inhibitors of SARS-CoV2 main protease
(M<sup>pro</sup>)
from the library of already FDA approved commercially available
drugs. The site-specific and blind docking studies, in combination,
suggest three potential inhibitors of M<sup>pro</sup>,
Ergotamine (ZINC000052955754), Nilotinib (ZINC000006716957) and
Naldemedine (ZINC000100378061). Molecular dynamics (MD) simulations
and binding free energy calculations using the MMPBSA method further
reinforced the efficiency of the screened M<sup>pro</sup>
inhibitor candidates. The work yields enough evidence to conduct
rigorous experimental validation of these drugs before utilizing them
for the therapeutic management of SARS-CoV2 infection.</p> | Gagandeep Singh; vishal srivastava; Ritpratik Mishra; Gaurav Goel; Tapan Chaudhuri | Theory - Computational; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-10-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7506b702a9b41ce18bd72/original/old-arsenal-to-combat-new-enemy-repurposing-of-commercially-available-fda-approved-drugs-against-main-protease-of-sars-co-v2.pdf |
635a54ffecdad5e88aef3518 | 10.26434/chemrxiv-2022-kdjjm | All-Organic Polymeric Materials with Extraordinarily High Refractive Index and Excellent Transparency | High refractive index polymers (HRIPs) have drawn increasing attention for their various optoelectronic applications. New HRIPs with excellent transparency, which could be facilely synthesized are highly demanded. Herein, sulfur-containing all organic HRIPs with refractive indices up to 1.8433 at 589 nm and excellent optical transparency even in micrometer scale in the visual and RI region as well as high weight-average molecular weights (up to 44500) were obtained by our newly established organobase catalyzed polymerization of bromoalkynes and dithiophenols in excellent yields (up to 92%). Notably, the fabricated optical transmission waveguides using the resultant HRIP with the highest refractive index displayed a reduced propagation loss compared with that generated by the commercial material of SU-8. In addition, the tetraphenylethylene (TPE) containing polymer also exhibit a reduced propagation loss and could be used to examine the uniformity and continuity of optical waveguides with naked eyes because of its aggregation-induced emission feature. Thus, this work not only provides new kind of all organic HRIPs potentially applicable in optical integrated field, but also develops a facile thiol-yne polymerization toward HRIPs. | Jie Zhang; Tianwen Bai; Weixi Liu; Qiguang Zang; Canbin Ye; Jing Zhi Sun; Yaocheng Shi; Jun Ling; Anjun Qin; Ben Zhong Tang | Polymer Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-10-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/635a54ffecdad5e88aef3518/original/all-organic-polymeric-materials-with-extraordinarily-high-refractive-index-and-excellent-transparency.pdf |
60c74166702a9b330118a255 | 10.26434/chemrxiv.8040131.v1 | Upcycling a Plastic Cup: One-Pot Synthesis of Lactate Containing Metal Organic Frameworks from Polylactic Acid | <p>Waste PLA can be upcycled to metal organic frameworks of potential high value in a one-pot synthesis scheme, where PLA depolymerisation occurs <i>in-situ</i>. Three lactate based frameworks were succesfully synthesised and characterised from PLA as a feed source, including homochiral framework ZnBLD. The chiral separation ability of ZnBLD was maintained.<br /></p><p><br /></p><p>Additional data including the CIF file, the CheckCIF document, and the raw XRD spectra, are available from the Zenodo repository linked below.<br /></p> | Benjamin Slater; So-On Wong; Andrew Duckworth; Andrew J. P. White; Matthew R. Hill; Bradley P. Ladewig | Hybrid Organic-Inorganic Materials; Nanostructured Materials - Materials; Coordination Chemistry (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2019-04-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74166702a9b330118a255/original/upcycling-a-plastic-cup-one-pot-synthesis-of-lactate-containing-metal-organic-frameworks-from-polylactic-acid.pdf |
65d779d166c138172943186c | 10.26434/chemrxiv-2024-rzgp3 | Ultrafast electronic and vibrational spectroscopy of electrochemical transformations on a metal-oxide surface during oxygen evolution from water | The oxygen evolution reaction (OER) from water fuels the planet through photosynthesis and is a primary means for hydrogen storage in energy technologies. Yet the detection of intermediates of OER central to the catalytic mechanism has been an ongoing challenge. This review covers the relevance of ultrafast electronic and vibrational spectroscopy of the electrochemical transformations of a metal-oxide surface undergoing OER. The electron doped SrTiO3/electrolyte is the system under review because of its high photocurrent efficiency with an ultrafast light trigger and because it allowed for detection of intermediate forms across the electromagnetic spectrum. The first part covers how the efficient catalytic reaction is triggered by ultrafast light pulses, describing the Schottky diode, the depletion layer, and Helmholtz layer under operating conditions to the extent possible. The second part covers the detection of the surface bound intermediates by transient spectroscopy. These target ultrafast (ps-ns) electron transfer from (or hole-trapping to) bound surface water species that are associated with the reactive oxygen intermediates of OER (e.g. OH*, O*). Their detection via a broadband visible probe, a mid-infrared evanescent wave, and coherent acoustic waves is then described. These target, respectively, the electronic states, the vibrational levels, and the lattice strain associated with the intermediates. The review is primarily concerned with how the measurements are made and the intermediates’ experimental spectra. The theoretical descriptions are brought in as a needed to provide context to spectra that are difficult to interpret on their own. A concluding section summarizes the essential findings and methodologies. | Tanja Cuk; Xihan Chen; Suryansh Singh; Michael Paolino; James Stewart; Ilya Vinogradov | Physical Chemistry; Catalysis; Energy; Heterogeneous Catalysis; Electrochemistry - Mechanisms, Theory & Study; Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65d779d166c138172943186c/original/ultrafast-electronic-and-vibrational-spectroscopy-of-electrochemical-transformations-on-a-metal-oxide-surface-during-oxygen-evolution-from-water.pdf |
60c75413567dfee94aec600a | 10.26434/chemrxiv.13606454.v1 | Chain-Growth Condensation Polymerization of Propargyl Electrophiles Enabled by Copper Catalysis | In the pursuit of creating macromolecules with controlled molecular weight, sequence, and end groups, condensation polymerization remains an underexploited synthetic tool because of its intrinsic step-growth nature. Introducing chain-growth pathways into condensation polymerization calls for highly efficient chemistries that effect the challenging differentiation between functional groups of the same type present in monomers and polymers. Here, we address this challenge by a catalyst bifurcation strategy that enables a copper-catalyzed chain-growth condensation polymerization. Using a copper(I) arylacetylide as an initiator/precatalyst along with a phosphine ligand, polydiynes of controllable molecular weights and end groups are synthesized from readily available propargyl carbonates, including a block copolymer. This method provides a new chain-growth access to functional acetylenic polymers, a class of useful materials that have been obtained essentially by step-growth methods to date. This work demonstrates the power of dual-role transition metal catalysis in accomplishing unusual selectivity in organic synthesis. | Han-Li Sun; Da-Qi Liu; Jun-Jie Wang; Dawen Niu; Rong Zhu | Polymerization (Polymers) | CC BY NC ND 4.0 | CHEMRXIV | 2021-01-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75413567dfee94aec600a/original/chain-growth-condensation-polymerization-of-propargyl-electrophiles-enabled-by-copper-catalysis.pdf |
60c74bebf96a0026bd2876c9 | 10.26434/chemrxiv.12401753.v1 | Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes | <p>High signal-to-noise optical voltage indicators will enable
simultaneous interrogation of membrane potential in large ensembles of neurons.
However, design principles for voltage sensors with high sensitivity and
brightness remain elusive, limiting the applicability of voltage imaging. In
this paper, we use molecular dynamics (MD) simulations and density functional
theory (DFT) calculations to guide the design of a bright and sensitive
green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that
uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD
simulations predict an 11% increase in sensitivity due to membrane orientation,
while DFT calculations predict an increase in fluorescence quantum yield, but a
decrease in sensitivity due to a decrease in rate of PeT. We confirm these
predictions by synthesizing a new VF dye and demonstrating that it displays the
expected improvements by doubling the brightness and retaining similar
sensitivity to prior VF dyes. Combining theoretical predictions and
experimental validation has resulted in the synthesis of the highest
signal-to-noise green VF dye to date. We use this new voltage indicator to
monitor the electrophysiological maturation of human embryonic stem
cell-derived medium spiny neurons. </p> | Rishikesh Kulkarni; Anneliese Gest; Chun Kei Lam; Benjamin Raliski; Feroz James; Maroof Adil; David Schaffer; Yi Wang; Evan Miller | Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74bebf96a0026bd2876c9/original/computationally-assisted-design-of-high-signal-to-noise-photoinduced-electron-transfer-based-voltage-sensitive-dyes.pdf |
63c3a47da68d7b61e2394376 | 10.26434/chemrxiv-2022-4k14h-v3 | Utilization of Tris(carbene)borate Ligands for Unique p-Block Element Isolation: Umpolung Reactivity of a Nucleophilic Tin(II) Cation Salt | We show that a tris(carbene)borate (TCB) ligand, namely [PhB(tBuIm)3]- ([PhB(tBuIm)3]- = phenyltris(3-tert-butylimidazol-2-ylidene)borato), is capable of stabilizing an unprecedented nucleophilic Sn(II) cation salt. Unlike known Sn(II) cations, the strong electron-donating ability of [PhB(tBuIm)3]- makes the cationic tin atom electron-rich, σ-donating yet slightly π-accepting, which allows for the ensuing facile oxidation with o-chloranil and S8 as well as coordination with coinage metals. The former oxidations give the Sn(IV) cation salts, while the latter reactions produce the metal complexes. The electronic structures of these species are thoroughly probed by quantum chemical computations. These results uncover an added role for TCB ligands in isolating unprecedented p-block species. | Chaopeng Hu; Liu Leo Liu | Inorganic Chemistry; Main Group Chemistry (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63c3a47da68d7b61e2394376/original/utilization-of-tris-carbene-borate-ligands-for-unique-p-block-element-isolation-umpolung-reactivity-of-a-nucleophilic-tin-ii-cation-salt.pdf |
60c73e3fbb8c1a57583d9896 | 10.26434/chemrxiv.6750062.v1 | Electronic Structure Origins of Surface-Dependent Growth in III-V Quantum Dots | <div><div><div><p>Indium phosphide quantum dots (QDs) have emerged as a primary candidate to replace more toxic II-VI CdSe QDs, but production of high-quality III-V InP QDs with targeted properties requires a better understanding of their growth. We develop a first-principles-derived model that unifies InP QD formation from isolated precursor and early stage cluster reactions to 1.3-nm magic size clusters, and we rationalize experimentally-observed properties of full sized > 3 nm QDs. Our first-principles study on realistic QD models reveals large surface-dependent reactivity for all elementary growth process steps including In-ligand bond cleavage and P precursor addition. These thermodynamic trends correlate well to kinetic properties at all stages of growth, indicating the presence of labile and stable spots on cluster and QD surfaces. Correlation of electronic or geometric properties to energetics identifies surprising sources for these variations: short In...In separation on the surface produces the most reactive sites, at odds with conventional understanding of strain (i.e., separation) in bulk metallic surfaces increasing reactivity and models for ionic II-VI QD growth. These differences are rationalized by the covalent, directional nature of bonding in III-V QDs and explained by bond order metrics derived directly from the In-O bond density. The unique constraints of carboxylate and P precursor bonding to In atoms rationalizes why all sizes of InP clusters and QDs are In-rich but become less so as QDs mature. These observations support the development of alternate growth recipes that take into account strong surface-dependence of kinetics as well as the shapes of both In and P precursors to control both kinetics and surface morphology in III-V QDs.</p></div></div></div> | Qing Zhao; Heather J. Kulik | Nanostructured Materials - Nanoscience; Computational Chemistry and Modeling; Clusters | CC BY NC ND 4.0 | CHEMRXIV | 2018-07-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e3fbb8c1a57583d9896/original/electronic-structure-origins-of-surface-dependent-growth-in-iii-v-quantum-dots.pdf |
6464ae0afb40f6b3eebaab70 | 10.26434/chemrxiv-2023-74w8d | Olympus, enhanced: benchmarking mixed-parameter and multi-objective optimization in chemistry and materials science | Experiment planning algorithms are a required component of autonomous platforms for scientific discovery. Selecting a suitable optimization algorithm for a novel application is an important yet difficult choice a researcher has to make based on past empirical performance on similar tasks. To facilitate the evaluation of various algorithms on chemistry and materials science optimization tasks, we previously introduced OLYMPUS (Mach. Learn.: Sci. Technol. 2, 035021, 2021), a Python package providing a consistent and easy-to-use interface to numerous optimization algorithms and benchmark datasets. While the original package was limited to continuous parameters and single objectives, in this work we expand OLYMPUS' capabilities to include mixed (continuous, discrete, and categorical) parameter types and multiple objectives. Several experiment planning algorithms already contained in OLYMPUS are extended to handle categorical and discrete parameter types, and five additional planners are implemented (23 in total). We also provide 23 additional benchmark datasets taken from the chemistry and materials science literature (33 in total), covering a wide range of research areas, from chemical reaction optimization to materials manufacturing. Finally, the visualization capabilities of OLYMPUS are enhanced to allow for easy inspection of the results, and the core functionality of the package is embedded in a Streamlit web application for code-free usage. We demonstrate how OLYMPUS enables researchers to rapidly benchmark different optimization strategies and gain insight into their behavior by focusing on two case studies: the optimization of a Suzuki-Miyaura cross-coupling reaction with categorical reaction conditions, and the multi-objective optimization of redox-active materials. The updated OLYMPUS package provides practitioners with a large suite of tools to efficiently benchmark and analyze experiment planning algorithms on mixed-parameter and multi-objective optimization tasks. | Riley Hickman; Priyansh Parakh; Austin Cheng; Qianxiang Ai; Joshua Schrier; Matteo Aldeghi; Alán Aspuru-Guzik | Theoretical and Computational Chemistry; Materials Science; Chemical Engineering and Industrial Chemistry; Materials Processing; Machine Learning; Reaction Engineering | CC BY 4.0 | CHEMRXIV | 2023-05-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6464ae0afb40f6b3eebaab70/original/olympus-enhanced-benchmarking-mixed-parameter-and-multi-objective-optimization-in-chemistry-and-materials-science.pdf |
66ffa10ecec5d6c1421c2460 | 10.26434/chemrxiv-2024-c82v8-v2 | A High-Throughput Framework for Lattice Dynamics | We develop an automated high-throughput workflow for calculating lattice dynamical properties from first principles including those dictated by anharmonicity. The pipeline automatically calculates interatomic force constants (IFC) up to 4th order from perturbed training supercells, and uses the IFC to calculate lattice thermal conductivity, coefficient of thermal expansion, and vibrational free energy and entropy. It performs phonon renormalization for dynamically unstable compounds to obtain real effective phonon spectra at finite temperatures and calculates the associated free energy corrections. The choice of methods and parameter selection process are done in a manner that strikes a balance of computational efficiency and accuracy of results (as assessed through convergence testing and comparison to experimental measurements). Deployment of this workflow at a large scale would facilitate materials discovery efforts toward functionalities including thermoelectics, contact materials, ferroelectrics, aerospace components, as well as general phase diagram construction. | Zhuoying Zhu; Junsoo Park; Hrushikesh Sahasrabuddhe; Alex Ganose; Rees Chang; John Lawson; Anubhav Jain | Theoretical and Computational Chemistry; Materials Science; Computational Chemistry and Modeling; Chemoinformatics - Computational Chemistry | CC BY 4.0 | CHEMRXIV | 2024-10-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66ffa10ecec5d6c1421c2460/original/a-high-throughput-framework-for-lattice-dynamics.pdf |
60c74238702a9b56bc18a3fb | 10.26434/chemrxiv.7297379.v2 | Molecular Transformer – A Model for Uncertainty-Calibrated Chemical Reaction Prediction | <div><div><div><p>Organic synthesis is one of the key stumbling blocks in medicinal chemistry. A necessary yet unsolved step in planning synthesis is solving the forward problem: given reactants and reagents, predict the products. Similar to other work, we treat reaction prediction as a machine translation problem between SMILES strings of reactants-reagents and the products. We show that a multi-head attention Molecular Transformer model outperforms all algorithms in the literature, achieving a top-1 accuracy above 90% on a common benchmark dataset. Our algorithm requires no handcrafted rules, and accurately predicts subtle chemical transformations. Crucially, our model can accurately estimate its own uncertainty, with an uncertainty score that is 89% accurate in terms of classifying whether a prediction is correct. Furthermore, we show that the model is able to handle inputs without reactant-reagent split and including stereochemistry, which makes our method universally applicable.</p></div></div></div> | Philippe Schwaller; Teodoro Laino; Theophile Gaudin; Peter Bolgar; Costas Bekas; Alpha A. Lee | Organic Synthesis and Reactions; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2019-05-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74238702a9b56bc18a3fb/original/molecular-transformer-a-model-for-uncertainty-calibrated-chemical-reaction-prediction.pdf |
66045479e9ebbb4db9b2a5db | 10.26434/chemrxiv-2024-wm9zq | Synthesis of Photoresponsive Water-Dispersible Magnetite Nanoparticles using Arylazopyrazole Modified Polymers | In order to design new nanomaterials with improved functionalities, magnetite nanoparticles (MNP) modified with arylazopyrazole (AAP) molecular photoswitches are presented. Water-dispersibility is achieved by using poly(acrylic acid) (pAA) as a multidentate ligand, which is modified with AAP by amide coupling. The polymer ligand allows for the E-Z isomerization of the photoswitch, stabilizes the nanoparticles and provides pH responsiveness. Three different AAPs are synthesized and attached to pAA via amide coupling giving statistic co-polymers pAA-AAP. MNP are synthesized by co-precipitation and pAA-AAP is introduced as stabilizing agent in situ. Photoisomerization of pAA-AAP and pAA-AAP@MNP are investigated showing good photostationary states and cyclability. The nanoparticles can be assembled and dispersed reversibly in water by applying magnetic field and change in the pH value. | Lisa Schlichter; Johann Jersch; Sergej Demokritov; Bart Jan Ravoo | Nanoscience | CC BY NC 4.0 | CHEMRXIV | 2024-03-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66045479e9ebbb4db9b2a5db/original/synthesis-of-photoresponsive-water-dispersible-magnetite-nanoparticles-using-arylazopyrazole-modified-polymers.pdf |
615ff88bb564b6a702705510 | 10.26434/chemrxiv-2021-3xx77 | Photo-excited Intramolecular Charge Transfer In Dye Sensitizers : Predictive In-silico Screening for Dye Sensitized Solar Cell Devices | Efficient photo-induced intramolecular charge transfer (ICT) from donor to acceptor in dye molecules is the functional basis and key property in the working of dye-sensitized solar cell (DSSC). To understand the ICT process in photo-excited dye molecules, we analyse the electronic properties and structural parameters of a chosen set of experimentally synthesized donor-acceptor (D-A) and donor-$\pi$--spacer-acceptor (D-$\pi$-A) type dye molecules in their ground, excited and cationic states. The correlation between structural modification and charge redistribution in different parts of the molecule helps to identify the extent of $\pi$-conjugation and spatial rearrangement of electron density localization along the molecular skeleton. We find that prominent twisting of several groups and resulting molecular bond rearrangements in larger parts of the molecule promotes efficient donor to acceptor ICT, such as in D-A type, ADEKA1 and C275 dyes. Thus based on modest computation of structural and electronic properties of dye molecules in their respective ground, excited and cationic states, we identify the desired structural changes that facilitate tunable intramolecular charge transfer to highlight a simple and direct prescription to screen out probable efficient dye molecules among many samples. Motivated by recent experimental evidence of capturing the structural view of the excited-state charge transfer in molecules, we provide a fresh outlook towards predictive and systematic computational screening and design of dye molecules, complementing parallel experimental approaches in the development of state-of-the-art DSSC. | Kalyani Chordiya; Ehesan Ali; Mousumi Upadhyay Kahaly | Theoretical and Computational Chemistry; Organic Chemistry; Organic Compounds and Functional Groups; Photochemistry (Org.); Theory - Computational; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-10-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/615ff88bb564b6a702705510/original/photo-excited-intramolecular-charge-transfer-in-dye-sensitizers-predictive-in-silico-screening-for-dye-sensitized-solar-cell-devices.pdf |
66bd1a97f3f4b05290e355c6 | 10.26434/chemrxiv-2024-htvk4 | Spin–State Energetics for Hydride and Helium Models of Transition Metal Complexes: A Benchmark Study of Wave Function Quantum Chemistry Methods | Accurate determination of spin–state energetics in first-row transition metal (TM) complexes is recognized as a challenging problem in computational quantum chemistry because different methods often yield divergent predictions and credible reference data are scarce. Trying to provide a way towards unambiguously accurate reference values from high-level wave function computation, a benchmark set of small TM complexes with hydrides (H^–) or helium atoms as σ-donor ligands is presented. These models have analogous electronic structures as realistic TM complexes and their spin–state energetics feature comparable method- dependence, but their small size enables application of more accurate methods than are applicable to realistic TM complexes. The extrapolated full configuration interaction (exFCI) results are obtained for selected spin–state splittings of the hydride/helium models and used as reference values for benchmarking various wave function methods, including second- and third-order perturbation theory multireference methods, multireference CI, and coupled cluster methods with up to approximate quadruples. It is demonstrated that the exFCI reference values can be reproduced satisfactorily with both multireference and single-reference methods, among which the NEVPT2 and CCSDT(Q)_Λ methods perform best, yielding deviations comparable with the uncertainties of the reference values or smaller than 2 kcal/mol. The CCSD(T) method yields errors of ca. 3 kcal/mol or smaller, with one exception where the CCSD(T)’s error is greater than 6 kcal/mol presumably due to pronounced multireference character. The CASPT2, CASPT3, CASPT2/CC methods are shown to not outperform the CCSD(T) method consistently. The present study, in addition to presenting novel benchmark set for the spin–state energetics problem, establishes hydride/helium models of TM complexes as useful and challenging systems for further investigations with correlated electronic structure methods. | Mariusz Radon | Theoretical and Computational Chemistry; Physical Chemistry; Inorganic Chemistry; Transition Metal Complexes (Inorg.); Computational Chemistry and Modeling; Theory - Computational | CC BY NC 4.0 | CHEMRXIV | 2024-08-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66bd1a97f3f4b05290e355c6/original/spin-state-energetics-for-hydride-and-helium-models-of-transition-metal-complexes-a-benchmark-study-of-wave-function-quantum-chemistry-methods.pdf |
6250f15aed4d885bdb056255 | 10.26434/chemrxiv-2022-xmz2v-v2 | Non-metal to metal transition of magnesia supported Au clusters affects the ultrafast dissociation dynamics of adsorbed CH3Br molecules | The detection of intermediate species and the correlation of their ultrafast dynamics with the morphology and electronic structure of a surface is crucial to fully understand and control heterogeneous photoinduced and photocatalytic reactions. In this work, the ultrafast photodissociation dynamics of CH3Br molecules adsorbed on variable size Au clusters on MgO/Mo(100) is investigated by monitoring the CH3+ transient evolution using a pump-probe technique in conjunction with surface mass spectrometry. Furthermore, extreme-ultraviolet photoemission spectroscopy in combination with theoretical calculations are employed to study the electronic structure of the Au cluster on MgO/Mo(100). Changes in the ultrafast dynamics of CH3+ fragment are correlated with the electronic structure of Au as it evolves from monomers to small nonmetallic clusters to larger nanoparticles with a metallic character. This work provides a new avenue to a detailed understanding of how surface photoinduced chemical reactions are influenced by the composition and electronic structure of the surface. | Mihai E. Vaida; Takat B. Rawal; Thorsten M. Bernhardt; Brett M. Marsh; Talat S. Rahman; Stephen R. Leone | Physical Chemistry; Clusters; Photochemistry (Physical Chem.); Surface | CC BY NC 4.0 | CHEMRXIV | 2022-04-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6250f15aed4d885bdb056255/original/non-metal-to-metal-transition-of-magnesia-supported-au-clusters-affects-the-ultrafast-dissociation-dynamics-of-adsorbed-ch3br-molecules.pdf |
63977ebf0fd99212bb439ca5 | 10.26434/chemrxiv-2022-3c4ht | A Diazaborine-Based Fluorescent Probe Tracks Endogenously Produced Peroxynitrite in Live Cells | We present the synthesis, properties, and imaging applications of Peroxynitrite Probe-1 (PNP-1), a novel organoboron-based probe for selective peroxynitrite (ONOO-) imaging in live cells. PNP-1 features a diazaborine-based reaction motif that provides excellent discrimination between H2O2 and ONOO-, solving a persistent challenge of organoboron-based fluorescent probes for oxidative metabolite imaging. We demonstrate the utility of PNP-1 to detect endogenously produced ONOO- in live RAW 264.7 macrophages, with probe selectivity confirmed by inhibition of NADPH oxidases and nitric oxide synthase, the requisite enzy-matic machinery for ONOO- production. Beyond the direct application of PNP-1, our results reveal that diazaborines are a modular reaction motif for selective ONOO- reactivity, positioning them for incorporation into other ONOO--specific chemical biology tools. | Jack Haggett; Dylan Domaille | Biological and Medicinal Chemistry; Organic Chemistry; Organic Synthesis and Reactions; Biochemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2022-12-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63977ebf0fd99212bb439ca5/original/a-diazaborine-based-fluorescent-probe-tracks-endogenously-produced-peroxynitrite-in-live-cells.pdf |
65241ac045aaa5fdbb9c5468 | 10.26434/chemrxiv-2023-0wdsk | How does structured adsorbent channel heterogeneity influence the efficiency of adsorptive CO2 capture? | Adsorbent monoliths are increasingly studied for carbon capture applications. Manufactured via extrusion, these monoliths often contain a heterogeneous distribution of channels, due to defects in the die or inhomogeneous drying. The effect of such heterogeneities on CO2 capture process performance is not well investigated. In this modelling work, the performance of a fixed bed, an ideal monolith and monoliths containing a wall size distribution are compared in a vacuum swing adsorption (VSA) cycle. At high adsorption gas velocities, using a monolith allows for a higher productivity (0.8 mmol/kg s) compared to a fixed bed (0.68 mmol/kg s) and a lower energy demand (190 kWh /ton CO2 versus 320 kWh/ton CO2). When the monolith contains a distribution of wall sizes, the process performance decreases. The recovery drops from 81 % to 65 % for the widest distribution studied (3σ=120%). Similarly, the throughput drops from 0.8 mmol/kg s to 0.6 mmol/kg s and the energy demand increases from 190 kWh /ton CO2 to 270 kWh/ton CO2. Our work thus shows that adsorbent monoliths can outperform a fixed bed of pellets in VSA cycles, leading to higher throughput and lower energy demand. The presence of defects, however, can severely impact performance. | Benjamin Claessens | Energy; Chemical Engineering and Industrial Chemistry; Transport Phenomena (Chem. Eng.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-10-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65241ac045aaa5fdbb9c5468/original/how-does-structured-adsorbent-channel-heterogeneity-influence-the-efficiency-of-adsorptive-co2-capture.pdf |
654267b748dad23120da99c0 | 10.26434/chemrxiv-2023-pptp2 | Oxidation-Induced Ambiphilicity Triggers N-N Bond Formation and Dinitrogen Release in Octahedral Terminal Molybdenum (V) Nitrido Complexes | Coupling of octahedral, terminal d1 molybdenum (V) nitrido complexes supported by a dianionic pentadentate ligand via N-N bond formation to give mu-dinitrogen complexes was found to be thermodynamically feasible but faces significant kinetic barriers. However, upon oxidation, a kinetically favored nucleophilic/electrophilic N-N bond forming mechanism was enabled to give monocationic mu-dinitrogen dimers. Computational and experimental evidence for this “oxidation induced ambiphilic nitrido coupling” mechanism is presented. The factors influencing release of dinitrogen from the resulting mu-dinitrogen dimers was also probed and it was found that further oxidation to a dicationic species is required to induce (very rapid) loss of dinitrogen. The mechanistic path discovered for N-N bond formation and dinitrogen release follows an ECECC sequence (E = “electrochemical step”; C = “chemical step”). Experimental evidence for the intermediacy of a highly electrophilic, cationic d0 molybdenum (VI) nitrido in the N-N bond forming mechanism via trapping with an isonitrile reagent is also discussed. Together these results are relevant to the development of molecular catalysts capable of mediating ammonia oxidation to dihydrogen and dinitrogen. | C. Christopher Almquist; Thayalan Rajeshkumar; H. D. A. Chathumal Jayaweera; Nicole Removski; Wen Zhou; Benjamin Gelfand; Warren Piers; Laurent Maron | Theoretical and Computational Chemistry; Inorganic Chemistry; Catalysis; Coordination Chemistry (Inorg.); Kinetics and Mechanism - Inorganic Reactions; Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-11-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/654267b748dad23120da99c0/original/oxidation-induced-ambiphilicity-triggers-n-n-bond-formation-and-dinitrogen-release-in-octahedral-terminal-molybdenum-v-nitrido-complexes.pdf |
659ff686e9ebbb4db9eec311 | 10.26434/chemrxiv-2024-h9sp9 | Effective removal of enteric viruses by Moringa oleifera seed extract functionalized cotton filter | Accessible and low-cost point-of-use technologies have significant potential to mitigate risk to public health, particularly in areas with limited resources and in disaster scenarios. Natural cotton fibers functionalized with water-soluble proteins from Moringa oleifera seeds (MO-cotton filter) are a promising technology at lab-scale with demonstrated feasibility for pathogen removal from water. Here, we showed the performance of MO-cotton filters under practically relevant conditions to remove mammalian virus spiked in groundwater. Specifically, MO-cotton filters achieved > 3.2-log10 reduction at a superficial velocity of 0.7 m/h of two mammalian viruses Tulane virus (TV, Caliciviridae, non-enveloped virus) and Transmissible gastroenteritis virus (TGEV, Coronaviridae, enveloped virus), which are representative of a significant portion of waterborne illnesses. We further evaluated the risk of virus particles detached due to shear forces by testing their infectivity and found that the viruses accumulated on the MO-cotton filters pose a minimal risk of contaminating the drinking water source. | Chamteut Oh; Gang Zheng; Laxmicharan Samineni; Manish Kumar; Thanh H. Nguyen | Earth, Space, and Environmental Chemistry; Environmental Science | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/659ff686e9ebbb4db9eec311/original/effective-removal-of-enteric-viruses-by-moringa-oleifera-seed-extract-functionalized-cotton-filter.pdf |
635cb36faca19892ffe9ebc4 | 10.26434/chemrxiv-2022-rhg14 | Chemical Elements, Flavor Chemicals, and Nicotine in Unused and Used Electronic Cigarettes Aged 5-10 Years and Effects of pH | The concentrations of elements/metals, nicotine, flavor chemicals and acids were com-pared in the
e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5-10
years. Metal analysis was done using inductively coupled plasma optical emission spectroscopy;
nicotine and flavor chemical analysis were measured using gas chromatography/mass spectroscopy. Of
22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin,
zinc) were often in the e-liquids. Five elements had the highest average concentrations: copper
(1,161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L).
Nicotine concentrations were always lower than label concentrations. Of 181 flavor chemicals
analyzed, 11 were measured in at least one sample, with hydroxyacetone being present in all
samples. In used products, some flavor chemicals appeared to be byproducts of heating. E-liquids
with the highest concentrations of acids and lowest pHs also had the highest concentrations of
elements/metals. Metal concentrations in e-liquids increased after use in some products, and some
metal concentrations, such as nickel, were high enough to be a health concern. Leachates from
discarded ECs could contribute toxic metals/chemicals to the environment sup-porting the need for
better regulation of atomizer design, composition, and disposal.
| Monique Williams; Wentai Luo; Kevin McWhirter; Omeka Ikegbu; Prue Talbot | Inorganic Chemistry; Minerals | CC BY NC 4.0 | CHEMRXIV | 2022-10-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/635cb36faca19892ffe9ebc4/original/chemical-elements-flavor-chemicals-and-nicotine-in-unused-and-used-electronic-cigarettes-aged-5-10-years-and-effects-of-p-h.pdf |
649d158cba3e99daef39e077 | 10.26434/chemrxiv-2023-5shbn-v2 | BODIPY-based Fluorescent Indicators for Lipid Droplets | Lipid droplets are essential for cellular lipid storage, playing critical roles in cellular lipid metabolism. Although lipid droplets have drawn intense research in recent years, much remains to be uncovered about the roles of this organelle in biology. Lipid droplet indicators exhibiting large Stokes shifts and improved brightness are therefore in demand. We report two asymmetric BODIPY derivatives, BoL1 and BoL2 bearing a benzothiazole group at the 6-position, which led to bathochromic shifts of 62 nm for BoL1 and 37 nm for BoL2 in fluorescence emission when compared to the reference molecules without the benzothiazole group. The incorporation of the benzothiazole moiety also resulted in a large Stokes shift of 40 nm. BoL1 and BoL2 have been demonstrated to operate as lipid droplet indicators in both confocal and STED imaging. BoL2 showed particularly good cellular retention and was further applied to explore the impact of cellular starvation on the trafficking of lipid droplets. | Jianping Zhu; Nian Kee Tan; Kai Kikuchi; Amandeep Kaur; Elizabeth J New | Biological and Medicinal Chemistry; Inorganic Chemistry; Sensors; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/649d158cba3e99daef39e077/original/bodipy-based-fluorescent-indicators-for-lipid-droplets.pdf |
67cd842dfa469535b9990eaf | 10.26434/chemrxiv-2025-kzss4 | Impact of Solvent Polarity on the Photoinduced Dynamics of a Push-Pull Molecular Motor | Light-driven rotary molecular motors convert light energy into unidirectional rotational movement. In overcrowded alkene-based molecular motors, rotary motion is accomplished through consecutive cis-trans photoisomerization reactions and thermal helix inversion steps. To date, a complete understanding of the photoisomerization reactions of overcrowded alkene motors has not been achieved yet. In this work, we use quantum chemical calculations and quantum mechanics/molecular mechanics (QM/MM) nonadiabatic dynamics simulations to investigate the photoinduced dynamics of a push-pull alkene-based molecular motor in two different solvents: cyclohexane and methanol. We show that, while in both solvents the main photorelaxation pathway of our investigated push-pull motor involves two different excited-state minima, in polar methanol the photorelaxation dynamics is much faster than in nonpolar cyclohexane because of two main effects: (i) a lowering of the energy barrier between the excited-state minima, and (ii) a reduction of the energy gap with the ground state at the largely twisted dark minimum, where the excited-state decay takes place. Both effects can be attributed to solvent-polarity stabilization of the charge-transfer excited state along the photorelaxation pathway. In line with the experimental findings, our simulations also indicate that in methanol the accelerated photoinduced dynamics goes along with a faster fluorescence decay and a large reduction in the forward photoisomerization yield of our investigated motor. | Davide Accomasso; Dominika Makoś | Theoretical and Computational Chemistry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67cd842dfa469535b9990eaf/original/impact-of-solvent-polarity-on-the-photoinduced-dynamics-of-a-push-pull-molecular-motor.pdf |
61e03aad4a603da8e12ec94f | 10.26434/chemrxiv-2022-7wkv6 | Local thermodynamics of alcohols from THz-calorimetry: Spectroscopic fingerprints of entropic loss and enthalpic gain | Hydration free energies are dictated by a subtle balance of hydrophobic and hydrophilic interactions. which is crucial for many biological processes and technological applications, such as protein folding and molecular recognition. Whereas so far the overall entropy and enthalpy are experimentally determined based on equilibrium measurements using a calorimeter, we present here a pure spectroscopic access to these important observables, which give direct access to the underlying molecular mechanism that determines these driving forces. Using THz calorimetry the contributions due to cavity formation and hydrophilic interactions can be traced back to changes in the intermolecular hydrogen bond stretching region around 150-200 cm−1 and spectroscopic changes due to strong solute-water interactions in the frequency range of the librational modes, i.e. between 540 and 600 cm−1. Thus, we are able to link the thermodynamic model of the Lum-Chandler-Weeks theory, which was a pure ”Gedankenexperiment”, directly to experimental observables. We show that alcohol hydration can be described by a sum of a free energy cost of forming and wrapping a cavity around the solute (which is entropic for small alcohols) and an enthalpic gain due to the hydrogen bonds formed between the alcohol OH group and bound water molecules around it. In the future, our approach will allow to quantify entropic cost and enthalpic gain not only in equilibrium but also in non-equilibrium processes. | Simone Pezzotti; Federico Sebastiani; Eliane P. van Dam; Sashary Ramos; Valeria Conti Nibali; Gerhard Schwaab; Martina Havenith | Physical Chemistry; Physical and Chemical Properties; Spectroscopy (Physical Chem.); Thermodynamics (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2022-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61e03aad4a603da8e12ec94f/original/local-thermodynamics-of-alcohols-from-t-hz-calorimetry-spectroscopic-fingerprints-of-entropic-loss-and-enthalpic-gain.pdf |
6234d96f5c8daeab81ee77d1 | 10.26434/chemrxiv-2022-5hdtp | Site-Selective Hydrogenation of Electron-Poor Alkenes and Dienes Enabled by a Rh-Catalyzed Hydride Addition/Protonolysis Mechanism | The transition metal catalyzed hydrogenation of alkenes is a well-developed technology used on a lab scale as well as on large scales in the chemical industry. Site- and chemoselective mono-hydrogenations of polarized conjugated dienes remain challenging. Instead, stoichiometric main-group hydrides are used rather than H2. As part of an effort to develop a scalable route to prepare geranylacetone, we discovered that Rh(CO)2acac/xantphos based catalysts enable the selective monohydrogenation of electron-poor 1,3-dienes, enones, and other polyunsaturated substrates. D-labeling and DFT studies support a mechanism where a nucleophilic Rh(I)-hydride selectively adds to electron-poor alkenes and the resulting Rh-enolate undergoes subsequent inner-sphere protonation by alcohol solvent. The finding that (Ln)Rh(H)(CO) type catalysts can enable selective mono-hydrogenation of electron-poor (poly)enes provides a valuable tool in the design of related chemoselective reduction processes of unsaturated substrates. | Duanyang Kong; Qiqige Qiqige; Wesley McNutt; Rocco Paciello; Ansgar Schäfer; Mathias Schelwies; Rylan Lundgren | Organic Chemistry; Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2022-03-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6234d96f5c8daeab81ee77d1/original/site-selective-hydrogenation-of-electron-poor-alkenes-and-dienes-enabled-by-a-rh-catalyzed-hydride-addition-protonolysis-mechanism.pdf |
67c180a6fa469535b94b0725 | 10.26434/chemrxiv-2025-cjls7-v2 | Frontier Orbital Changes Induce Slow-down of Excited State Population Dynamics in Thiopyridone Isomers | The non-adiabatic dynamics of photoexcited thiopyridone systems were studied across their ortho-, meta-, and para-isomeric forms. Surface hopping dynamics, utilizing TDDFT based electronic structure calculations, elucidate the relaxation pathways of the three constitutional isomers in both gas-phase and solvation environments. Particular attention is given to intersystem crossing (ISC) and non-adiabatic dynamics in triplet states, as the lowest triplet state plays a critical role in driving the excited-state proton transfer process in the ortho isomer. The efficiency of singlet-triplet crossings was analyzed by evaluating electronic features and energy gaps derived from dynamic simulations. The investigations suggest a systematic reduction in the rate of ISC from ortho to meta to para isomer. Furthermore, a comparison with a multireference approach in the gas phase highlights how variations in electronic structure influence the observed dynamics. | Sambit Kumar Das; Douglas Garratt; Kelly Gaffney; Michael Odelius | Theoretical and Computational Chemistry; Physical Chemistry; Organic Chemistry; Computational Chemistry and Modeling; Theory - Computational; Photochemistry (Physical Chem.) | CC BY 4.0 | CHEMRXIV | 2025-02-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c180a6fa469535b94b0725/original/frontier-orbital-changes-induce-slow-down-of-excited-state-population-dynamics-in-thiopyridone-isomers.pdf |
6642860491aefa6ce1e3ffac | 10.26434/chemrxiv-2024-vlh6f | Particle-particle interface corrosion of cold sprayed copper in dilute nitric acid solution: Geometry-controlled corrosion mechanism | The mechanism of particle-particle interface (PPI) corrosion observed in cold sprayed (CS) Cu immersed in dilute HNO3 has been elucidated. PPI corrosion is initiated by the oxide inclusions present along the PPIs. The accelerated corrosion rate at PPIs results from the combined effects of confined geometry and catalytic reactions, which involve the electrochemical dissolution of Cu and reduction of NO3−. Annealing the CS Cu at 600°C coalesces the oxide inclusions, thereby breaking the interconnected oxide inclusion network. As a result, the propagation of PPI corrosion is impeded. | Xuejie Li; Fraser Filice; Jeffrey Henderson; Mehran Behazin; Sridhar Ramamurthy; Ivan Barker; Sebastian Skaanvik; Reza Moshrefi; Samantha Gateman; David Shoesmith; James Noël | Physical Chemistry; Materials Science; Coating Materials; Chemical Kinetics; Interfaces | CC BY NC ND 4.0 | CHEMRXIV | 2024-05-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6642860491aefa6ce1e3ffac/original/particle-particle-interface-corrosion-of-cold-sprayed-copper-in-dilute-nitric-acid-solution-geometry-controlled-corrosion-mechanism.pdf |
6104336b393cc9238e50060b | 10.26434/chemrxiv-2021-wsg4q | Active Learning Configuration Interaction for Excited States Calculations of Polycyclic Aromatic Hydrocarbons | We present the active learning configuration interaction (ALCI) method for multiconfigurational calculations based on large active spaces. ALCI leverages the use of an active learning procedure to find important electronic configurations among the full configuration space generated within an active space. We tested it for the calculation of singlet-singlet excited states of acenes and pyrene, by using different machine learning algorithms. The ALCI method yields excitation energies within 0.2–0.3 eV from those obtained by traditional complete active space configuration interaction (CASCI) calculations (affordable for active spaces up to 16 electrons in 16 orbitals), by including only a small fraction of the CASCI configuration space in the calculations. For larger active spaces (up to 26 electrons in 26 orbitals), not affordable with traditional CI methods, ALCI captures the trends of experimental excitation energies. Overall ALCI provides satisfactory approximations to large active-space wave functions with up to ten orders of magnitude fewer configurations. These ALCI wave functions are promising and affordable starting points for subsequent second order perturbation theory or pair-density functional theory calculations. | WooSeok Jeong; Carlo Alberto Gaggioli; Laura Gagliardi | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational; Machine Learning | CC BY NC ND 4.0 | CHEMRXIV | 2021-08-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6104336b393cc9238e50060b/original/active-learning-configuration-interaction-for-excited-states-calculations-of-polycyclic-aromatic-hydrocarbons.pdf |
668f7f4101103d79c5aca6de | 10.26434/chemrxiv-2024-h9tvm-v3 | Ligand Tail Controls the Conformation of Indium Sulfide ultrathin nanoribbons | We report the conformational control of 2D ultra-thin indium sulfide nanoribbons by tuning their amine ligands' alkyl chain. The initial orthorhombic InS nanoribbons bare octylamine ligands and display a highly curved geometry with a characteristic figure of eight shapes. Exchanging the native ligand by oleylamine induces their complete unfolding to yield flat board-shaped nanoribbons. Significant strain variations in the InS crystal structure accompany this shape-shifting. By tuning the linear alkyl chain length from 4 to 18 carbon atoms, we show using SAXS in solution and TEM that the curvature of the nanoribbon subtly depends on the ligand-ligand interactions at the nanoribbon's surface. The curvature decreases gradually as the chain length increases, while carbon unsaturation has an unexpectedly significant effect at constant chain length. These experiments shed light on the critical role of the ligand monolayer on the curvature of ultrathin 2D crystalline nanosheets and demonstrate that weak supramolecular forces within the organic part of colloidal nanocrystals can dramatically impact their shape. This transduction mechanism, in which changes in the organic monolayer impact the shape of a nanocrystal, will help devise new strategies to design stimuli-responsive systems that take advantage of both the flexibility of organic moieties and the physical properties of the inorganic core. | Lilian Guillemeney; Sarit Dutta; Rodolphe Valleix; Gilles Patriarche ; Benoit Mahler; Benjamin Abecassis | Nanoscience | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/668f7f4101103d79c5aca6de/original/ligand-tail-controls-the-conformation-of-indium-sulfide-ultrathin-nanoribbons.pdf |
62bbf386253021766382acae | 10.26434/chemrxiv-2022-wxxtq | Elucidating N-acyl amino acids as a model protoamphiphilic system | Protoamphiphiles are prebiotically-plausible moieties that would have constituted protocell membranes on early Earth. Although prebiotic soup would have contained a diverse set of amphiphiles capable of generating protocell membranes, earlier studies were mainly limited to fatty acid-based systems. Herein, we characterize N-acyl amino acids (NAAs) as a model protoamphiphilic system. Specifically, we report a new abiotic route for their synthesis under wet-dry cycles from amino acids and monoglycerides via an ester-amide exchange process. We also demonstrate how N-oleoyl glycine (NOG, a representative NAA) results in vesicle formation over a broad pH range when blended with a monoglyceride or a fatty acid. Notably, NOG also acts as a substrate for peptide synthesis under wet-dry cycles, generating different lipopeptides. Overall, our study establishes NAAs as a promising protoamphiphilic system, and highlights their significance in generating robust and functional protocell membranes on primitive Earth. | Manesh Prakash Joshi; Ashwin Uday; Sudha Rajamani | Biological and Medicinal Chemistry; Biochemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-06-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62bbf386253021766382acae/original/elucidating-n-acyl-amino-acids-as-a-model-protoamphiphilic-system.pdf |
61e23a95b815cc13f395e954 | 10.26434/chemrxiv-2022-q6pfj | Alternative Perspective on Rapid Wine Oxidation through Changes in Gas-Phase Volatile Concentrations, Highlighted by Matrix Component Effects | A new perspective is presented to investigate the sensorially relevant gas-phase concentrations of volatile compounds in wine. This is achieved by measuring the partition coefficients and matrix-phase concentrations of volatiles using static headspace-gas chromatography-ion mobility spectrometry (SHS-GC-IMS). Physicochemical properties that can contribute to the partition behaviors of ten volatile esters, such as hydrophobicity and matrix temperature, are also discussed. Partition coefficients are then linked to quantitative measurements to obtain partial pressures, which describes the availability of volatile compounds in the gas phase. The concept of partition coefficients and partial pressure have then been applied to a time series of aroma changes due to oxidation in commercial wines. As a follow-up study, a full factorial design was devised to inspect the impact of three common wine matrix components, namely, copper, polyphenols and ascorbic acid, on the partial pressure changes after 30-day oxidation treatment in either full-alcohol or low-alcohol simulated wine matrices. Interesting interactive effects between antioxidant behaviors and alcohol levels were elucidated, especially around the controversial use of ascorbic acid in winemaking. These results can guide winemakers who wish to minimize oxidative damage to wine aroma during wine storage or bulk transport, where ullage may be present or continual oxygen ingress may be occurring. | Wenyao Zhu; Frank Benkwitz; Paul Kilmartin | Analytical Chemistry; Agriculture and Food Chemistry; Analytical Chemistry - General; Separation Science; Food | CC BY NC 4.0 | CHEMRXIV | 2022-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61e23a95b815cc13f395e954/original/alternative-perspective-on-rapid-wine-oxidation-through-changes-in-gas-phase-volatile-concentrations-highlighted-by-matrix-component-effects.pdf |
67da353e6dde43c9085d2a2f | 10.26434/chemrxiv-2025-zw2n4 | Electrochemical Oxidation of Benzyl Alcohols via Hydrogen Atom Transfer Mediated by 2,2,2-Trifluoroethanol | We report a novel electrochemical oxidation of benzyl alcohols. We found that trifluoroethanol plays a role as a hydrogen atom transfer (HAT) mediator, enabling the oxidation of electron-deficient substrates that are difficult to directly oxidize on electrode surfaces. Density-functional theory calculations, cyclic voltammetry measurements and constant potential electrolysis studies supported the proposed HAT mechanism. Moreover, the obtained carbonyl compounds could be functionalized in an electro-chemically one-pot manner, further highlighting their synthetic utility. | Takahiro Kawajiri; Masahiro Hosoya; Satoshi Goda; Eisuke Sato; Seiji Suga | Organic Chemistry; Catalysis; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67da353e6dde43c9085d2a2f/original/electrochemical-oxidation-of-benzyl-alcohols-via-hydrogen-atom-transfer-mediated-by-2-2-2-trifluoroethanol.pdf |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.