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
⌀ |
|---|---|---|---|---|---|---|---|---|---|
60c73e1c4c8919f376ad1d3a | 10.26434/chemrxiv.5758608.v2 | η^2 bonded Nickel(0) thiophene π-complexes - identifying the missing link in catalyst transfer polymerization | <p>We have structurally characterized a nickel(0) thiophene complex that represents a close analog to the proposed intermediates in the mechanism of catalyst transfer polycondensation (CTP) of thiophenes. Additional studies on this intermediate allow us to determine the bonding in such complexes using a combination of nuclear magnetic resonance spectroscopy, X-ray absorption spectroscopy, and DFT-based computations. Our structure
of the catalyst agrees with previous postulates but provides important new
structural insights into the species. Furthermore, our studies explain why these complexes
actually exist and are stable enough to support living CTP.</p> | Weiying He; Brian O. Patrick; Pierre Kennepohl | Catalysis; Polymerization (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2018-05-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e1c4c8919f376ad1d3a/original/2-bonded-nickel-0-thiophene-complexes-identifying-the-missing-link-in-catalyst-transfer-polymerization.pdf |
60c74c86bb8c1a83083db430 | 10.26434/chemrxiv.12496730.v1 | Bistable Spin-Crossover in a New Series of [Fe(BPP-R)2] 2+ (BPP = 2,6-Bis(pyrazol-1-Yl)pyridine; R =CN) Complexes | <p><i>A new series of iron(II) complexes—[Fe(BPP-CN)<sub>2</sub>](X)<sub>2</sub>,
X = BF<sub>4</sub> <b>(1a-d) </b>or ClO<sub>4 </sub><b>(2)</b>—belonging to the
[Fe(BPP-R)<sub>2</sub>]<sup>2+</sup> (BPP = 2,6-bis(pyrazol-1-yl)pyridine) family of complexes showed abrupt
and hysteretic, that is, bistable, spin-crossover (SCO) characteristics. Among
the complexes, the lattice solvent-free complex <b>2</b> showed a stable and
complete SCO (T<sub>1/2 </sub>= 241 K) with a thermal hysteresis width (ΔT) of
28 K, the widest ΔT so far reported for a [Fe(BPP-R)<sub>2</sub>](X)<sub>2 </sub>family
of complex, showing abrupt SCO. The reproducible and bistable SCO shown by the relatively
simple [Fe(BPP-CN)<sub>2</sub>](X)<sub>2 </sub>series of molecular complexes is
encouraging to pursue [Fe(BPP-R)<sub>2</sub>]<sup>2+</sup> systems for the
realization of technologically relevant SCO complexes. </i></p> | Senthil Kumar Kuppusamy; Nicolas Del Giudice; Benoit Heinrich; Laurent Douce; Mario Ruben | Coordination Chemistry (Inorg.); Ligands (Inorg.); Magnetism; Transition Metal Complexes (Inorg.); Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74c86bb8c1a83083db430/original/bistable-spin-crossover-in-a-new-series-of-fe-bpp-r-2-2-bpp-2-6-bis-pyrazol-1-yl-pyridine-r-cn-complexes.pdf |
66f126b412ff75c3a130abaa | 10.26434/chemrxiv-2024-bx32v | Microenvironment tailoring for electrocatalytic CO2 reduction: Effects of interfacial structure on controlling activity and selectivity | The performance of the electrocatalytic CO2 reduction reaction (CO2RR) is highly dependent on the microenvironment around the cathode. Despite efforts to optimize the microenvironment by modifying nanostructured catalysts or microporous gas diffusion electrodes, their inherent disorder presents a significant challenge to understanding how interfacial structure arrangement within the electrode governs the microenvironment for CO2RR. This knowledge gap limits fundamental understanding of CO2RR while also hindering efforts to enhance CO2RR selectivity and activity. In this work, we investigate this knowledge gap using a tunable system featuring hierarchical Cu nanowire arrays that possess adjustable microgroove dimensions. Adjusting the NAM structure tunes multiple synergistic effects in the microenvironment, which include stabilization of the microwetting state, confinement of CO*, improvement to local CO2 concentration, and modulation of the local pH. Notably, using mass transport modeling, we quantify the role of the gas-liquid-solid interface in boosting local CO2 concentrations within several microns of the interface itself. Leveraging these effects, we elucidate how CO* and H* competitively occupy active sites, influencing reaction pathways toward multicarbon products based on tuning the microenvironment. Consequently, we provide new insights into why the optimized configuration significantly increased CO2RR activity by 690% (as normalized by electrochemical active surface area), C2+ product selectivity by 72%, and Faradaic efficiency by 36%, compared to CO2RR with hydrophobic Cu foil. Based on these insights, our findings unlock new opportunities to engineer the CO2RR microenvironment through the rational organization of hierarchical interface materials in gas diffusion electrodes towards improved CO2RR selectivity and activity. | Yaqi Cheng; Muhammad Iskandar B. Salaman; Qixun Li; Chaolong Wei; Qilun Wang; Xuehu Ma; Bin Liu; Andrew Wong | Catalysis; Electrocatalysis; Nanocatalysis - Reactions & Mechanisms; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66f126b412ff75c3a130abaa/original/microenvironment-tailoring-for-electrocatalytic-co2-reduction-effects-of-interfacial-structure-on-controlling-activity-and-selectivity.pdf |
65bdbf279138d231615203dd | 10.26434/chemrxiv-2024-t5hxg | A Fluorine Rich Borate Ionic Additive Enabling High-Voltage Li Metal Batteries | Lithium-metal batteries (LMBs) are promising alternatives to state-of-the-art Lithium-ion batteries (LIBs) to achieve higher energy densities. However, the poor cyclability of LMBs resulting from Li metal anode (Li0) irreversibility and concomitant electrolyte decompositions limits their practical applications. In this study, we reported a per-fluorinated salt, lithium tetrakis(perfluoro-tertbutyloxy)borate (abbreviated as Li-TFOB) as an electrolyte additive for Li metal batteries, which contains 36 F atoms per molecule. This newly designed ionic additive tuned the chemical composition of the solid-electrolyte interphase (SEI) on Li0 by increasing the amount of LiF and Li-B-O inorganic species. DFT calculations and Molecular dynamics (MD) simulations indicated the preferential reduction of the TFOB anions at Li0, which occurs with a lower free energy change than PF6- anions. The designed ionic additive enables the 4.6 V Li||LiNi0.6Mn0.2Co0.2O2 (NMC622) cell to achieve an average CE of 99.1% and a high-capacity retention of > 50% after 500 cycles. This experiment-simulation joint study illustrated an attractive approach to accelerating the design of electrolytes and interphases for LMBs. | Liping Zhang; Dengpan Dong; Arthur Cresce; Qianshun Wei; Dmitry Bedrov; Kang Xu; T. Leo Liu | Energy; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65bdbf279138d231615203dd/original/a-fluorine-rich-borate-ionic-additive-enabling-high-voltage-li-metal-batteries.pdf |
6602a91566c1381729d8eb51 | 10.26434/chemrxiv-2024-6cwvw | Exploration of the polymorphic solid-state landscape of an amide-linked organic cage using computation and automation | Organic cages can possess complex, functionalised internal cavities that make them promising candidates for synthetic enzyme mimics. Conformationally flexible but chemically robust structures are needed for adaptable guest binding and catalysis, but these rapidly exchanging systems are difficult to resolve in solution. Here, we use inexpensive calculations and high-throughput crystallisation experiments to identify accessible cage conformations for a recently reported organic cage by ‘locking’ them in the solid state. The conformers identified exhibit a range of distances between the carboxylic acid groups in the internal cavity, suggesting adaptability towards binding a wide array of target guest molecules. The complexity of the observed crystal structures goes beyond what is possible with state-of-the-art crystal structure prediction. | Caitlin Shields; Thomas Fellowes; Anna Slater; Andrew Cooper; Keith Andrews; Filip Szczypiński | Theoretical and Computational Chemistry; Organic Chemistry; Materials Science; Supramolecular Chemistry (Org.); Computational Chemistry and Modeling; Crystallography – Organic | CC BY NC 4.0 | CHEMRXIV | 2024-03-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6602a91566c1381729d8eb51/original/exploration-of-the-polymorphic-solid-state-landscape-of-an-amide-linked-organic-cage-using-computation-and-automation.pdf |
60c74c174c89194fd0ad357e | 10.26434/chemrxiv.12421082.v1 | Holistic Prediction of pKa in Diverse Solvents Based on Machine Learning Approach | The
acid dissociation constant p<i>K</i><sub>a</sub>
dictates a molecule’s ionic status, and is a critical physicochemical property
in rationalizing acid-base chemistry in solution and in many biological
contexts. Although numerous theoretic approaches have been developed for
predicating aqueous p<i>K</i><sub>a</sub>, fast
and accurate prediction of non-aqueous p<i>K</i><sub>a</sub>s
has remained a major challenge. On the basis of <i>i</i>BonD experimental p<i>K</i><sub>a</sub>
database curated across 39 solvents, a holistic p<i>K</i><sub>a</sub> prediction model was established by using machine
learning approach. Structural and physical organic parameters combined
descriptors (SPOC) were introduced to represent the electronic and structural
features of molecules. With SPOC and ionic status labelling (ISL), the holistic models trained with neural network or XGBoost algorithm
showed the best prediction performance <a>with MAE value as
low as 0.87</a> p<i>K</i><sub>a</sub> unit. The
holistic model showed better performance than all the tested single-solvent
models (SSMs), verifying the transfer learning features. The capability of
prediction in diverse solvents allows for a comprehensive mapping of all the
possible p<i>K</i><sub>a</sub> correlations
between different solvents. The <i>i</i>BonD
holistic model was validated by prediction of aqueous p<i>K</i><sub>a</sub> and micro-p<i>K</i><sub>a</sub>
of pharmaceutical molecules and p<i>K</i><sub>a</sub>s
of organocatalysts in DMSO and MeCN with high accuracy. An on-line prediction platform
(<a href="http://pka.luoszgroup.com/">http://pka.luoszgroup.com</a>) was constructed based on the current model. | Qi Yang; Yao Li; Jin-Dong Yang; Yidi Liu; Long Zhang; Sanzhong Luo; Jin-Pei Cheng | Machine Learning | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74c174c89194fd0ad357e/original/holistic-prediction-of-p-ka-in-diverse-solvents-based-on-machine-learning-approach.pdf |
6549ec72c573f893f1fb3626 | 10.26434/chemrxiv-2023-4vs5w | A bridge between trust and control: Computational workflows meet automated battery cycling | Compliance with good research data management practices means trust in the integrity of the data, and it is achievable by a full control of the data gathering process. In this work, we demonstrate tooling which bridges these two aspects, and illustrate its use in a case study of automated battery cycling. We successfully interface off-the-shelf battery cycling hardware with the computational workflow management software AiiDA, allowing us to control experiments, while ensuring trust in the data by tracking its provenance. We design user interfaces compatible with this tooling, which span the inventory, experiment design, and result analysis stages. Other features, including monitoring of workflows and import of externally generated and legacy data are also implemented. Finally, the full software stack required for this work is made available in a set of open-source packages. | Peter Kraus; Edan Bainglass; Francisco F. Ramirez; Enea Svaluto-Ferro; Loris Ercole; Benjamin Kunz; Sebastiaan P. Huber; Nukorn Plainpan; Nicola Marzari; Corsin Battaglia; Giovanni Pizzi | Physical Chemistry; Materials Science; Energy; Electrochemistry - Mechanisms, Theory & Study | CC BY 4.0 | CHEMRXIV | 2023-11-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6549ec72c573f893f1fb3626/original/a-bridge-between-trust-and-control-computational-workflows-meet-automated-battery-cycling.pdf |
66b692a55101a2ffa8c3f559 | 10.26434/chemrxiv-2024-z6t01 | Ligand content and driving force effects on ion-ion permselectivity in ligand-functionalized membranes | Ion-selective membranes could enable sustainable critical material separations processes because of their scalability, low energy consumption, and low chemical input. The effects of membrane water content and incorporation of ion-coordinating ligands have been studied via computation and experiment to develop structure-performance relationships. However, few studies systematically investigate the effects of membrane composition beyond monomer chemical identity or the balance of driving forces such as diffusion and electromigration. Here we synthesized a library of poly(ethylene glycol) acrylate membranes with varying percentages of ion-coordinating monomers (acrylic acid, 4-vinylpyridine) to investigate the influence of ligand content on ion permeabilities and permselectivities. Trends in membrane performance under electrodialysis and diffusion were compared to elucidate the relative effects of separation driving forces and to inform electrochemical operation. We observed order-of-magnitude permeability reductions with ligand content for ions capable of multidentate ligand complexation, especially for nickel in the pyridine-containing membranes. As a result, lithium/nickel permselectivity gradually increased by a factor of 1.65× from 10 to 50 mol% pyridine membranes. We further demonstrated simultaneous improvements in lithium/nickel separation productivity (1.75×) and selectivity (2.99×) with increasing electric potential driving force. Ultimately, results from this study provide design insights for ligand-functionalized membranes in electrified ion-ion separations processes. | Kristen Abels; Amilton Barbosa Botelho Junior; Xi Chen; William Tarpeh | Materials Science; Polymer Science; Chemical Engineering and Industrial Chemistry; Coordination polymers; Transport Phenomena (Chem. Eng.); Water Purification | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66b692a55101a2ffa8c3f559/original/ligand-content-and-driving-force-effects-on-ion-ion-permselectivity-in-ligand-functionalized-membranes.pdf |
60c742f19abda284c2f8c0e9 | 10.26434/chemrxiv.8862254.v1 | Real-Time in Situ Monitoring of Particle and Structure Evolution in Mechanochemical Synthesis of UiO-66 Metal-Organic Framework | Manuscript about monitoring the mechanochemical reaction of a
metal-organic framework model system by in situ X-ray powder diffraction<br /> | Luzia S. Germann; Athanassios D. Katsenis; Igor Huskić; Patrick
A. Julien; Krunoslav Uzarevic; Martin Etter; Omar
K. Farha; Tomislav Friscic; Robert E. Dinnebier | Hybrid Organic-Inorganic Materials; Solid State Chemistry; Coordination Chemistry (Organomet.); Kinetics and Mechanism - Organometallic Reactions; Crystallography; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2019-07-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c742f19abda284c2f8c0e9/original/real-time-in-situ-monitoring-of-particle-and-structure-evolution-in-mechanochemical-synthesis-of-ui-o-66-metal-organic-framework.pdf |
65cda7bb66c1381729aedc67 | 10.26434/chemrxiv-2024-9jmfb | Divergent Total Syntheses of Pyrroloiminoquinone Alkaloids Ena-bled by the Development of a Larock/Buchwald–Hartwig Annula-tion/Cyclization | ABSTRACT: Pyrroloiminoquinone alkaloids are a large class of natural products that display a wide range of biologi-cal activities. Synthetic approaches to these natural products typically rely on a common late-stage C10-oxygenated pyrroloiminoquinone intermediate, but these strategies often lead to lengthy synthetic sequences that are not ame-nable to divergent syntheses. We devised an alternative approach aimed at the early introduction of the C10 nitro-gen, which we hypothesized would enable late-stage diversification. This strategy hinged upon a Larock/Buchwald–Hartwig annulation/cyclization to quickly access the core of these alkaloids. We report the development of this cas-cade process, which was facilitated by a dual ligand system in addition to selective functionalization of the key inter-mediate, to provide the shortest total syntheses to date of makaluvamines A, C, and D and isobatzelline B, and the first total synthesis of makaluvamine N. | Samir Rezgui; Jonathan Farhi ; Hao Yu ; Zachary Sercel ; Scott Virgil; Brian M. Stoltz | Organic Chemistry; Natural Products; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65cda7bb66c1381729aedc67/original/divergent-total-syntheses-of-pyrroloiminoquinone-alkaloids-ena-bled-by-the-development-of-a-larock-buchwald-hartwig-annula-tion-cyclization.pdf |
6491a716853d501c00320835 | 10.26434/chemrxiv-2023-52xjr | Spectral tuning and excitation-energy transfer by unique carotenoids in diatom light-harvesting antenna | The light-harvesting antennae of diatoms and spinach are composed of similar chromophores; however, they exhibit different absorption wavelengths. Recent advances in cryoelectron microscopy have revealed that the diatom light-harvesting antenna fucoxanthin chlorophyll a/c-binding protein (FCPII) forms a tetramer and differs from the spinach antenna in terms of the number of protomers; however, the detailed molecular mechanism remains elusive. Herein, we report the physicochemical factors contributing to the difference in light absorption between the light-harvesting antennae of diatoms and spinach based on spectral calculations using an exciton model. Spectral analysis reveals the significant contribution of unique fucoxanthins (fucoxanthin-S) in FCPII to the diatom-specific spectrum, and further analysis determines their essential role in the excitation-energy transfer to chlorophyll. The findings of this study demonstrate that diatoms employ fucoxanthin-S to harvest energy under the ocean in the absence of long-wavelength sunlight and can provide significant information on the survival strategies of photosynthetic organisms to adjust to their living environment. | Kazuhiro J. Fujimoto; Takuya Seki; Takumi Minoda; Takeshi Yanai | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Biophysical Chemistry; Photochemistry (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6491a716853d501c00320835/original/spectral-tuning-and-excitation-energy-transfer-by-unique-carotenoids-in-diatom-light-harvesting-antenna.pdf |
611bdfa55322c152fc03bcfb | 10.26434/chemrxiv-2021-vcj33 | Synthesis of Phenanthridine by Palladium Catalyzed Suzuki Coupling and Condensation Reaction | Transition metal catalyzed cross-coupling reactions such as Suzuki-Miyaura, Heck, Stille, Negishi, and Sonogashira reactions are likely to be the most power tool for the formation of C-C bonds for the past four decades. All these reactions have shown their widespread applicability ranging from academic area to research. Some of the reactions have also been applied in pharmaceuticals, agrochemicals, and fine material industries. Herein we report a one-pot strategy to achieve phenanthridine and analogous derivatives via Suzuki coupling of suitably substituted aromatic ortho-bromoaldehyde and ortho-aminobenzenboronic acid in quantitative to good yields | Jayanta Kumar Ray; Suvendu Dhara | Organic Chemistry; Materials Science; Organometallic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Catalysts | CC BY 4.0 | CHEMRXIV | 2021-08-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/611bdfa55322c152fc03bcfb/original/synthesis-of-phenanthridine-by-palladium-catalyzed-suzuki-coupling-and-condensation-reaction.pdf |
626c10f288636c210823f525 | 10.26434/chemrxiv-2022-jhv7t | Palladium Nanocrystals-embedded Covalent Organic Framework (Pd@COF) as Efficient Catalyst for Heck Cross-Coupling Reaction | Nanoparticles, such as noble metal nanoparticles and covalent organic frameworks (COFs), advance heterogeneous catalysis. Three COFs were synthesized via the solvothermal method using tricarboxylic acids (tricarboxylic benzene (2,4,6-tri-p-carboxyphenylpyridine (H3L2), 4,4',4''-tri carboxyl triphenylamine (H3L1), and trimesic acid (H3BTC)) and 1,3,5-Triazine-2,4,6-triamine moieties. The synthesized COFs were potentially used as supports for the in-situ growth of palladium nanocrystals (Pd NCs), offering a particle size of 1-5 nm. X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), nitrogen adsorption-desorption isotherms, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) characterized the materials. Using Heck cross-coupling reaction, Pd NCs@COFs were used as catalysts to synthesize different organic molecules via carbon-carbon (C-C) formation. They exhibit complete conversion (100%) for vinyl derivatives and aryl halides (Bromo- and Chloro-derivatives) with good stability. Pd NCs@COFs maintain high catalytic activity over four consecutive cycles. | Hani Nasser Abdelhamid; Ahmed R Abdellah; Abu-Bakr AAM El-Adasy; Ahmed A Atalla; Kamal I Ali | Organic Chemistry; Catalysis; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-05-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/626c10f288636c210823f525/original/palladium-nanocrystals-embedded-covalent-organic-framework-pd-cof-as-efficient-catalyst-for-heck-cross-coupling-reaction.pdf |
60c74701bb8c1abc4c3da9a7 | 10.26434/chemrxiv.11474589.v1 | A Molecular Mechanism for Azeotrope Formation in Ethanol/benzene Binary Mixtures Through Gibbs Ensemble Monte Carlo Simulation | Azeotropes have been studied for decades due to the challenges they impose on separation processes but fundamental understanding at the molecular level remains limited. Although molecular simulation has demonstrated its capability of predicting mixture vapor-liquid equilibrium (VLE) behaviors, including azeotropes, its potential for mechanistic investigation has not been fully exploited. In this study, we use the united atom transferable potentials for phase equilibria (TraPPE-UA) force-field to model the ethanol/benzene mixture, which displays a positive azeotrope. Gibbs ensemble Monte Carlo (GEMC) simulation is performed to predict the VLE phase diagram, including an azeotrope point. The results accurately agree with experimental measurements. We argue that the molecular mechanism of azeotrope formation cannot be fully understood by studying the mixture liquid-state stability at the azeotrope point alone. Rather, azeotrope occurrence is only a reflection of the changing relative volatility between the two components over a much wider composition range. A thermodynamic criterion is thus proposed based on the comparison of partial excess Gibbs energy between the components. In the ethanol/benzene system, molecular energetics shows that with increasing ethanol mole fraction, its volatility initially decreases but later plateaus, while benzene volatility is initially nearly constant and only starts to decrease when its mole fraction is low. Analysis of the mixture liquid structure, including a detailed investigation of ethanol hydrogen-bonding configurations at different composition levels, reveals the underlying molecular mechanism for the changing volatilities responsible for the azeotrope. | Dongyang Li; Ziqi Gao; Naveen Kumar Vasudevan; Hong Li; Xin Gao; Xingang Li; Li Xi | Physical and Chemical Properties; Thermodynamics (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2019-12-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74701bb8c1abc4c3da9a7/original/a-molecular-mechanism-for-azeotrope-formation-in-ethanol-benzene-binary-mixtures-through-gibbs-ensemble-monte-carlo-simulation.pdf |
6565e35a29a13c4d472f6f0f | 10.26434/chemrxiv-2023-7x8pz-v2 | Structure-activity studies of 1,2,4-oxadiazoles for the inhibition of the NAD+ dependent lysine deacylase Sirtuin2 | The NAD+-dependent lysine deacylase Sirtuin2 (Sirt2) is involved in multiple pathological conditions, including cancer and targeting Sirt2 has thus received an increased interest for therapeutic purpose. Furthermore, addressing the ortholog from Schistosoma mansoni (SmSirt2) has been considered for the potential treatment of the neglected tropical disease schistosomiasis. We previously identified a 1,2,4-oxadiazole-based scaffold from the screening of the “Kinetobox” library as a dual inhibitor of human Sirt2 and SmSirt2. Herein, we describe structure-activity studies on 1,2,4-oxadiazole based analogs, which are potent inhibitors of human Sirt2 deacetylation. As proposed by docking studies, a substrate competitive and co-factor non-competitive binding mode of inhibition could be determined in vitro via binding assays and kinetic analysis, and further confirmed by a crystal structure of an oxadiazole inhibitor in complex with hSirt2. Optimized analogs reduced cell viability and inhibited prostate cancer cell migration, in correlation with Sirt2 deacetylase inhibition both in vitro and in cells. | Arianna Colcerasa; Florian Friedrich; Jelena Melesina; Patrick Moser; Anja Vogelmann; Pavlos Tzortzoglou; Emilia Neuwirt; Manuela Sum; Lin Zhang; Elizabeth Ramos-Morales; Christophe Romier; Oliver Einsle; Eric Metzger; Roland Schüle; Olaf Gross; Wolfgang Sippl; Manfred Jung | Biological and Medicinal Chemistry; Biochemistry; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY NC 4.0 | CHEMRXIV | 2023-11-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6565e35a29a13c4d472f6f0f/original/structure-activity-studies-of-1-2-4-oxadiazoles-for-the-inhibition-of-the-nad-dependent-lysine-deacylase-sirtuin2.pdf |
6227ae0757a9d23ce2780fdb | 10.26434/chemrxiv-2022-p9rzx | Characterization of a new G-type halohydrin dehalogenase with enhanced catalytic activity | Biochemical characterization of HheG-682, a new homolog of halohydrin dehalogenase HheG sharing 46% sequence identity, is presented. | Sophie Günther; Anett Schallmey | Catalysis; Biocatalysis | CC BY 4.0 | CHEMRXIV | 2022-03-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6227ae0757a9d23ce2780fdb/original/characterization-of-a-new-g-type-halohydrin-dehalogenase-with-enhanced-catalytic-activity.pdf |
61c70559a53f1bf118a7cd8f | 10.26434/chemrxiv-2021-m8793 | From Germacarbonyl Compounds’ Perspective: Glad to be Formed and Stable in the Real World | Germacarbonyl compounds are the germanium analogs of carbonyl compounds, and they require an inert atmosphere for stability. Making these compounds survive the ambient conditions was not feasible given the lability of the Ge=E bonds (E = O, S, Se, Te). However, the first examples of germacarbonyl compounds synthesized under ambient conditions by taking advantage of dipyrromethene ligand stabilization are detailed here; the isolated compounds are germanones 3-4, germacarboxylic acids 6-7, germaesters 9-10, and germaamides 12-13 with Ge=E bonds (E = S, Se). The germaamides 12-13 can react under atmospheric conditions with copper(I) halides offering air and water stable monomeric 14-15 and dimeric 16-19 copper(I) complexes (halide = Cl, Br, I). Apart from just binding, selectivity was also observed; thiogermaamide 12 and selenogermaamide 13 bind CuCl and CuBr, respectively, when treated with a mixture of copper(I) halides.
| Pritam Mahawar; Pratima Shukla; Prakash Chandra Joshi; Dharmendra Singh; Nagendran Selvarajan | Organometallic Chemistry; Coordination Chemistry (Organomet.); Main Group Chemistry (Organomet.); Transition Metal Complexes (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-12-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61c70559a53f1bf118a7cd8f/original/from-germacarbonyl-compounds-perspective-glad-to-be-formed-and-stable-in-the-real-world.pdf |
6415b0592bfb3dc251f8c858 | 10.26434/chemrxiv-2023-h67ws | Understanding Formation of the InPd3 Polymorphs: A DFT Study | The intriguing experimental results regarding the synthesis and structure types adopted by binary InPd3 have been fundamentally addressed using first-principles density functional theory calculations. Longer annealing time at higher temperature leads to stronger and more optimized heteroatomic In-Pd contacts that result in the extended ordering between them and leading to the ZrAl3-structure type; followed by another ordered derivative TiAl3-type and the metastable disordered AuCu-type when the annealing time and temperature were reduced. The thermodynamic stability order of these three polymorphs of InPd3; i.e. ZrAl3-type > TiAl3-type > AuCu-type is understood from the correlation between formation enthalpies, Madelung energies, and electronic structure, chemical bonding analysis. | NILANJAN ROY | Theoretical and Computational Chemistry; Inorganic Chemistry; Bonding; Solid State Chemistry; Materials Chemistry; Crystallography – Inorganic | CC BY 4.0 | CHEMRXIV | 2023-03-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6415b0592bfb3dc251f8c858/original/understanding-formation-of-the-in-pd3-polymorphs-a-dft-study.pdf |
67537bcd7be152b1d02e2f1e | 10.26434/chemrxiv-2024-l2jgc | Designing Electrocatalytic Mediators and Understanding Site-selectivity for C(sp3)-H Activation Using First-Principles Calculations | Selective C-H bond activation is one of the most critical molecular transformations in synthesizing chemicals, pharmaceuticals, and natural product intermediates with broad applications. Recent efforts have focused on developing electrocatalytic mediators that rapidly and selectively activate specific C-H bonds. These mediated activations offer multiple benefits over direct electrochemical oxidation as they can occur at lower overpotentials, leading to higher faradaic efficiency and selectivity with reduced solvent oxidation. Our previous work described the development of N-alkyl ammonium ylides as a new class of electro-oxidative mediators. Despite its importance, the underlying principles of designing efficient mediators and understanding their site-selectivity are yet to be fully elucidated. The work discussed herein scrutinized mediator design using density functional theory calculations to highlight the critical features of mediators that govern C(sp3)-H activation. The design of newer mediators is guided by scaling relationships between the thermodynamic descriptors associated with the elementary steps involved in C(sp3)-H activation. We subsequently examine the results from detailed transition state calculations to elucidate the site-selectivity for C(sp3)-H activation for various substrates with quinuclidine and ylide mediators. The results show the critical interplay of thermodynamic, steric, and electronic features of the substrate and mediator that govern the corresponding site-selectivity. Finally, we present unifying trends across multiple substrates and mediators to understand the site-selectivity for mediated electrocatalytic C(sp3)-H activations and push our efforts toward predicting regio-selectivity in the future. | Mayank Tanwar; Yu Kawamata; Phil S. Baran; Matthew Neurock | Theoretical and Computational Chemistry; Organic Chemistry; Catalysis; Computational Chemistry and Modeling; Electrocatalysis; Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2024-12-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67537bcd7be152b1d02e2f1e/original/designing-electrocatalytic-mediators-and-understanding-site-selectivity-for-c-sp3-h-activation-using-first-principles-calculations.pdf |
64c7b3d4658ec5f7e57d4140 | 10.26434/chemrxiv-2023-pzbr6-v2 | Computational Study on the Route of Cooperative Organocatalysis Utilizing Thiourea and Halogen Bond Donor Mixture | A computational analysis of possible routes of cooperative catalysis involving hydrogen bond donating thiourea and halogen bond donating organocatalysts has been carried out at the M06-2X/SDD level of theory using the solvation model based on density (SMD). For the model systems involving thiourea and 2-iodoimidazolium or iodonium salt derivatives, the previously suggested route including sequential electrophilic activation of a reaction electrophile via XB-activated HB donor was ruled out. | Alexander S. Novikov; Dmitrii S. Bolotin | Theoretical and Computational Chemistry; Organic Chemistry; Catalysis; Physical Organic Chemistry; Homogeneous Catalysis; Organocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64c7b3d4658ec5f7e57d4140/original/computational-study-on-the-route-of-cooperative-organocatalysis-utilizing-thiourea-and-halogen-bond-donor-mixture.pdf |
60c73e82337d6c4384e26352 | 10.26434/chemrxiv.6993521.v1 | Implementation of Slow Magnetic Relaxation in a SIM-MOF Through a Structural Rearrangement | <p>Here we report the structural flexibility of a Dy-based Single-Ion Magnet MOF in which its magnetic properties can be modified through a ligand substitution process involving an increase of the charge density of the coordination environment.</p> | Guillermo Minguez Espallargas; Javier Castells-Gil; Carlos Marti-Gastaldo; Jose J. Baldovi | Magnetic Materials; Coordination Chemistry (Inorg.); Lanthanides and Actinides; Magnetism; Polymers | CC BY NC ND 4.0 | CHEMRXIV | 2018-08-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e82337d6c4384e26352/original/implementation-of-slow-magnetic-relaxation-in-a-sim-mof-through-a-structural-rearrangement.pdf |
60c74a5f0f50db7529396a70 | 10.26434/chemrxiv.12195084.v1 | Control of Porphyrin Planarity and Aggregation by Covalent Capping: Bissilyloxy Porphyrin Silanes | <div>
<div>
<div>
<p>Porphyrins are cornerstone functional materials that are useful in a wide variety of settings ranging from molecular
electronics to biology and medicine. Their applications are often hindered, however, by poor solubilities that result from their extended, solvophobic aromatic surfaces. Attempts to counteract this problem by functionalizing their peripheries have been met with
only limited success. Here, we demonstrate a versatile strategy to tune the physical and electronic properties of porphyrins using an
axial functionalization approach. Porphyrin silanes (PorSils) and bissilyloxy PorSils (SOPS) are prepared from porphyrins by operationally simple κ4N-silylation protocols, introducing bulky silyloxy “caps” that are central and perpendicular to the planar porphyrin.
While porphyrins typically form either J- or H-aggregates, SOPS do not self-associate in the same manner: the silyloxy axial substituents dramatically improve solubility by inhibiting aggregation. Moreover, axial porphyrin functionalization offers convenient handles through which optical, electronic, and structural properties of the porphyrin core can be modulated. We observe that the identity
of the silyloxy substituent impacts the degree of planarity of the porphyrin in the solid state as well as the redox potentials.
</p>
</div>
</div>
</div> | Burhan A. Hussein; Zainab Shakeel; Andrew T. Turley; Aisha N. Bismillah; Kody Wolfstadt; Julia Pia; Melanie Pilkington; Paul R. McGonigal; Marc Adler | Physical Organic Chemistry; Crystallography – Organic | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74a5f0f50db7529396a70/original/control-of-porphyrin-planarity-and-aggregation-by-covalent-capping-bissilyloxy-porphyrin-silanes.pdf |
60c758a9567dfe0613ec68b4 | 10.26434/chemrxiv.14555151.v1 | Cross-coupling Reactions of Monosubstituted Tetrazines | <div><div><div><p>A fast and mild method for the Pd-catalyzed cross-coupling reaction of monosubstituted 3-bromo-1,2,4,5-tetrazine is presented. Investigation of silver-based additives revealed that Ag2CO3 is the optimal mediator, enabling the process without the need for strong bases or high temperatures. Electronic modification of the classical 1,1′- bis(diphenylphosphine)ferrocene (dppf) ligand proved to be a powerful strategy in tailoring the catalytic system to the requirements set by the process. Under the optimized conditions a scope comprising a variety of alkyl-, heteroatom-, and halide substituted aryl- and heteroaryl-tetrazines were prepared in good to excellent yields (29 examples, up to 87% yield). This method constitutes the first example of a direct cross-coupling reaction of monosubstituted tetrazines.</p></div></div></div> | Lukas Hoff; Simon Schnell; Andrea Tomio; Anthony Linden; Karl Gademann | Bioorganic Chemistry; Organic Synthesis and Reactions; Chemical Biology; Homogeneous Catalysis; Crystallography – Organic | CC BY NC ND 4.0 | CHEMRXIV | 2021-05-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c758a9567dfe0613ec68b4/original/cross-coupling-reactions-of-monosubstituted-tetrazines.pdf |
628bf0ca59f0d6b8549b0bfb | 10.26434/chemrxiv-2022-cs6fj | Deep neural network based quantum simulations and quasichemical theory for accurate modeling of molten salt thermodynamics | With dual goals of efficient and accurate modeling of solvation thermodynamics in molten salt liquids, we employ ab initio molecular dynamics (AIMD) simulations, deep neural network interatomic potentials (NNIP), and quasichemical theory (QCT) to calculate the excess chemical potentials for the solute ions Na$^{+}$ and Cl$^{-}$ in the molten NaCl liquid. NNIP-based molecular dynamics simulations accelerate the calculations by 3 orders of magnitude and reduce the uncertainty to 1 kcal/mol. Using the Density Functional Theory (DFT) level of theory, the predicted excess chemical potential for the solute ion pair is -178.5$\pm$1.1 kcal/mol. A quantum correction of 13.7$\pm$1.9 kcal/mol is estimated via higher-level quantum chemistry calculations, leading to a final predicted ion pair excess chemical potential of -164.8$\pm$2.2 kcal/mol. The result is in good agreement with a value of $-163.5$ kcal/mol obtained from thermo-chemical tables. This study validates the application of QCT and NNIP simulations to the molten salt liquids, allowing for significant insights into the solvation thermodynamics crucial for numerous molten salt applications. | Thomas Beck; Yu Shi; Stephen Lam | Physical Chemistry; Energy | CC BY 4.0 | CHEMRXIV | 2022-05-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/628bf0ca59f0d6b8549b0bfb/original/deep-neural-network-based-quantum-simulations-and-quasichemical-theory-for-accurate-modeling-of-molten-salt-thermodynamics.pdf |
63995370b103afea54185582 | 10.26434/chemrxiv-2022-kl3v5 | A Long Journey to the Unknown Chemical Space: Synthesis of Ferrocene 1,3-Derivatives by Distal C-H Activation by a Template Approach | Reaching the unreachable! Ferrocene derivatives have found wide applications as ligands, catalysts, functionalized materials, fuel additives, agrochemicals, drugs and many bioorganometallic compounds. Planar chiral ferrocene derivatives are bench-mark ligands used in asymmetric catalysis both in bulk chemical industry and fine chemical synthesis. Traditionally, ferrocene-1,2-derivatives were prepared by lithiation-electrophilic quenching protocol, which is still being pursued, until recently when transition-metal catalyzed C-H activation came into play. But till date, the third position of Cp ring of ferrocene remained as hitherto inaccessible chemical space for the direct functionalization in the ferrocene and bypassing the active second position is most challenging task and beyond common comprehension. Here we report the regiospecific 1,3functionalization of ferrocene via covalently bound pyridine containing template directed approach with precise selectivity under Pd(II)/MPAA catalytic system. The process shows broad scope in olefins with ferrocenylmethylamine in moderate to good yields via highly strained 12-membered macrocyclophane-like pre-transition state with appended ferrocene. We believe that this result will pave the way towards the development of novel class of ferrocene pincer ligands that would be an addition to the repertoire of toolbox of ligands available for synthetic organic chemist. | Princi Gupta; Suchithra Madhavan; Manmohan Kapur | Organic Chemistry; Catalysis; Organometallic Chemistry; Organic Synthesis and Reactions; Bond Activation; Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2022-12-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63995370b103afea54185582/original/a-long-journey-to-the-unknown-chemical-space-synthesis-of-ferrocene-1-3-derivatives-by-distal-c-h-activation-by-a-template-approach.pdf |
60c7585e9abda24fe1f8e8c4 | 10.26434/chemrxiv.14547384.v1 | Synthesis of Twisted [N]Cycloparaphenylenes by Alkene Insertion | This paper describes a new synthetic method of p-conjugated Mobius molecule by inserting an alkene or ortho-phenylene to cycloparaphenylenes. Physical properties of the obtained compounds were also studied. | Tomoaki Terabayashi; Eiichi Kayahara; Yoshiyuki Mizuhata; Norihiro Tokitoh; Toru Nishinaga; Tatsuhisa Kato; Shigeru Yamago | Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-05-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7585e9abda24fe1f8e8c4/original/synthesis-of-twisted-n-cycloparaphenylenes-by-alkene-insertion.pdf |
6349563ee3f3ee154e5a2158 | 10.26434/chemrxiv-2022-cj4tx | Ultralarge-Pore, Record-Low Density Three-Dimensional Covalent Organic Framework for Controlled Drug Delivery | The unique structural characteristics of three-dimensional (3D) covalent organic frameworks (COFs) like high surface areas, interconnected pore system and readily accessible active sites render them promising platforms for a wide set of functional applications. Albeit promising, the reticular construction of 3D COFs with large pores is a very demanding task owing to the formation of interpenetrated frameworks. Herein we report the designed synthesis of a 3D non-interpenetrated stp net COF, namely TUS-64, with the largest pore size of all 3D COFs (47 Å) and record-low density (0.106 g cm-3) by reticulating a 6-connected triptycene-based linker with a 4-connected porphyrin-based linker. Characterized with a highly interconnected mesoporous scaffold and good stability, TUS-64 shows efficient drug loading and controlled release for five different drugs in simulated body fluid environment, demonstrating the competency of TUS-64 as drug nanocarriers | Yu Zhao; Saikat Das; Taishu Sekine; Haruna Mabuchi; Tsukasa Irie; Jin Sakai; Dan Wen; Teng Ben; Yuichi Negishi | Polymer Science; Drug delivery systems; Organic Polymers; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-10-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6349563ee3f3ee154e5a2158/original/ultralarge-pore-record-low-density-three-dimensional-covalent-organic-framework-for-controlled-drug-delivery.pdf |
60c75243469df44048f44b38 | 10.26434/chemrxiv.13277495.v1 | Silica Sol-Gel Microbead Encapsulation as a Novel Delivery Method for Symbiotic Microbes | Synthetic fertilizer is responsible for the greatly increased crop yields that have enabled worldwide industrialization. However, the production and use of such fertilizers are environmentally unfriendly and unsustainable; synthetic fertilizers are produced via non-renewable resources and fertilizer runoff causes groundwater contamination and eutrophication. A promising alternative to synthetic fertilizer is bacterial inoculation. In this process, a symbiotic relationship is formed between a crop and bacteria species that can fix nitrogen, solubilize phosphorus, and stimulate plant hormone production. The bacteria carrier developed here aims to maintain bacteria viability while in storage, protect bacteria while encapsulated, and provide a sustained and controllable bacterial release. This novel bacterial delivery method utilizes inorganic nanomaterials, silica microbeads, to encapsulate symbiotic bacteria. These microbeads, which were produced with aqueous, non-toxic precursors, are sprayed directly onto crop seeds and solidify on the seeds as a resilient silica matrix. The bacterial release from the carrier was found by submerging coated seeds in solution to simulate degradation in soil environments, measuring the number of bacteria released by the plate count technique, and comparing the carrier to seeds coated only in bacteria. The carrier’s effectiveness to enhance plant growth was determined through greenhouse plant assays with alfalfa (<i>Medicago sativa</i>) plants and the nitrogen-fixing <i>Sinorhizobium meliloti</i> Rm1021 strain. When compared to bacteria-only inoculation, the silica microbead carrier exhibited significantly (P < 0.05) increased holding capacity of viable bacteria and increased plant growth by a similar amount, demonstrating the capability of inorganic nanomaterials for microbial delivery. The carrier presented in this work has potential applications for commercial agriculture and presents an opportunity to further pursue more sustainable agricultural practices. | Luke Elissiry; Jingwen Sun; Ann M. Hirsch; Chong Liu | Biocompatible Materials; Hydrogels | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75243469df44048f44b38/original/silica-sol-gel-microbead-encapsulation-as-a-novel-delivery-method-for-symbiotic-microbes.pdf |
60c74ac59abda2816ef8cf26 | 10.26434/chemrxiv.12250199.v1 | Antiretroviral Drug Activity and Potential for Pre-Exposure Prophylaxis Against COVID-19 and HIV Infection | <p>COVID-19 is the disease caused by SARS-CoV-2, and has led to over 250,000 deaths by May 2020. Urgent studies to identify new antiviral drugs, repurpose existing drugs, or identify those drugs that can specifically target the overactive immune response are ongoing around the world. Antiretroviral drugs (ARVs) have been tested in past human coronavirus infections, and also against SARS-CoV-2, but a recent clinical trial of lopinavir and ritonavir failed to show any clinical benefit in COVID-19 disease. However, anecdotal reports suggest either reduced infection or a course of milder COVID-19 disease in people living with HIV (PLWH) on ARVs. We hypothesized ARVs other than lopinavir and ritonavir might be responsible for such effects. Here, we used chemoinformatic analyses to predict which ARVs would bind and potentially inhibit the SARS-CoV-2 main protease or RNA-dependent RNA polymerase enzymes, and identified a number of ARVs which bind to SARS-CoV-2 enzymes in silico. Our study identified HIV nucleoside/nucleotide analogue reverse transcriptase inhibitors (abacavir, emtricitabine, lamivudine, tenofovir, zidovudine), HIV protease inhibitors (ASC09, atazanavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir, tipranavir) and an HIV pharmacokinetic booster (cobicistat), as drug candidates with effective in silico binding to one or both viral enzymes. Tenofovir and emtricitabine are FDA-approved as HIV pre-exposure prophylaxis (PrEP) and have an extensive safety profile of use in populations without HIV. Existing or new combinations of antiretroviral drugs could potentially prevent or ameliorate the course of COVID-19, if shown to inhibit SARS-CoV-2 in vitro and/or in clinical trials. Further studies are needed to establish the activity of ARVs for treatment or prevention of SARS-CoV-2 infection.</p> | Dennis C. Copertino Jr.; Bruno Lima; Rodrigo Duarte; Timothy Wilkin; Roy Gulick; Miguel de Mulder Rougvie; Douglas Nixon | Drug Discovery and Drug Delivery Systems; Microbiology | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74ac59abda2816ef8cf26/original/antiretroviral-drug-activity-and-potential-for-pre-exposure-prophylaxis-against-covid-19-and-hiv-infection.pdf |
60c744b7702a9bd94a18a8a4 | 10.26434/chemrxiv.7851848.v3 | On the Linear Geometry of Lanthanide Hydroxide (Ln—OH, Ln=La-Lu) | Lanthanide hydroxides are key species in a variety of catalytic processes and in the preparation of corresponding oxides. This work explores the fundamental structure and bonding of the simplest lanthanide hydroxide, LnOH (Ln=La-Lu), using density functional theory calculations. Interestingly, the calculations predict that all structures of this series will be linear. Furthermore, these results indicate a valence electron configuration featuring an occupied sigma orbital and two occupied pi orbitals for all LnOH compounds, suggesting that the lanthanide-hydroxide bond is best characterized as a covalent triple bond. | Hassan Harb; Lee Thompson; Hrant Hratchian | Bonding; Lanthanides and Actinides; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2019-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c744b7702a9bd94a18a8a4/original/on-the-linear-geometry-of-lanthanide-hydroxide-ln-oh-ln-la-lu.pdf |
6425e562647e3dca99c44d0e | 10.26434/chemrxiv-2023-qw7tv | Insight into the structural ambiguity of actinide(IV) oxalate sheet structures: a case for alternate coordination geometries | Plutonium(IV) oxalate hexahydrate (Pu(C2O4)2∙6H2O; PuOx) is an important intermediate in the recovery of plutonium from used nuclear fuel. Its formation via precipitation is well studied, yet its crystal structure remains unknown. Instead, the crystal structure of PuOx is assumed to be isostructural with neptunium(IV) oxalate hexahydrate (Np(C2O4)¬2∙6H2O; NpOx) and uranium(IV) oxalate hexahydrate (U(C2O4)¬2∙6H2O; UOx) despite the high degree of unresolved disorder that exists when determining water positions in the crystal structures of the latter two compounds. Such assumptions regarding the isostructural behavior of the actinide elements have been used to predict the structure of PuOx for use in a wide range of studies. Herein, we report the first crystal structures for PuOx and Th(C2O4)2·6H2O (ThOx). This data, along with new characterization of UOx and NpOx, has resulted in the full determination of the structures and resolution of the disorder around the water molecules. Specifically, we identify the coordination of two water molecules with each metal center, which necessitates a change in oxalate coordination mode from axial to equatorial that has not been reported in the literature. The results of this work exemplify the need to revisit previous assumptions regarding fundamental actinide chemistry, which are heavily relied upon within the current nuclear field. | A. Kirstin Sockwell; Teagan F. M. Sweet; Brodie Barth; Sara B. Isbill; Nicole A. DiBlasi; Jennifer E. S. Szymanowski; Ginger E. Sigmon; Allen G. Oliver; Andrew J. Miskowiec; Peter C. Burns; Amy E. Hixon | Inorganic Chemistry; Lanthanides and Actinides; Nuclear Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6425e562647e3dca99c44d0e/original/insight-into-the-structural-ambiguity-of-actinide-iv-oxalate-sheet-structures-a-case-for-alternate-coordination-geometries.pdf |
631c5b7e3e2e36da35316e97 | 10.26434/chemrxiv-2022-9k1lb | ANTIMICROBIAL ACTIVITY: DIFFERENT MECHANISTIC ELUCIDATION OF ANTIBACTERIAL, ANTIVIRAL, ANTIFUNGAL & ANTIALGAE AGENTS | In recent days, increasing number of microbes and their increasing resistance power against conventional drugs lead to enormous worldwide mortalities, hence they become a great threat to human health. The modern era is already going through the threat of COVID 19, which is also caused by one of those microbes called virus. In order to get a clear understanding, all the microbes have been classified in certain types. Now a days, to develop new alternative antimicrobial medicines, the scientists must acquire clarity about the responsible functional groups of different conventional drugs with proper mechanistic elucidation on different types of microbes. This information not only clarify the functionalities and properties responsible to exhibit antimicrobial effects, but also facile the idea of new drug development in future through proper functional group incorporation or modification. In this essay, my focus will majorly be on the main four types of microbes and their possible mechanistic elucidation of commonly used antibiotics and alternative antimicrobial medicines discovered till now. | Ishita Mukherjee | Biological and Medicinal Chemistry; Microbiology | CC BY NC ND 4.0 | CHEMRXIV | 2022-09-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/631c5b7e3e2e36da35316e97/original/antimicrobial-activity-different-mechanistic-elucidation-of-antibacterial-antiviral-antifungal-antialgae-agents.pdf |
60c73e9d702a9b2c65189dfc | 10.26434/chemrxiv.5877555.v5 | Why Is Safe Science Good Science? | In science, safety can seem unfashionable. Satisfying safety requirements can slow the pace of research, make it cumbersome, or cost significant amounts of money. The logic of rules can seem unclear. Compliance can feel like a negative incentive. So besides the obvious benefit that safety keeps one safe, why do some scientists preach "safe science is good science"? Understanding the principles that underlie this maxim might help to create a strong positive incentive to incorporate safety into the pursuit of groundbreaking science.<div><br /></div><div>This essay explains how safety can enhance the quality of an experiment and promote innovation in one's research. Being safe induces a researcher to have <b>greater control</b> over an experiment, which reduces the <b>uncertainty</b> that characterizes the experiment. Less uncertainty increases both <b>safety</b> and the <b>quality</b> of the experiment, the latter including <b>statistical quality</b> (reproducibility, sensitivity, etc.) and <b>countless other properties</b> (yield, purity, cost, etc.). Like prototyping in design thinking and working under the constraint of creative limitation in the arts, <b>considering safety issues</b> is a hands-on activity that involves <b>decision-making</b>. Making decisions leads to new ideas, which spawns <b>innovation</b>.</div> | Camilla Kao; Che-I Kao; Russell Furr | Chemical Education - General | CC BY 4.0 | CHEMRXIV | 2018-02-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e9d702a9b2c65189dfc/original/why-is-safe-science-good-science.pdf |
661cf41a91aefa6ce198164c | 10.26434/chemrxiv-2023-0fkv3-v2 | Electrosynthesis of iron-based metal-organic materials with bis(salicylic acid) derivatives | Continuous advancements in understanding and controlling surface functionalisation and properties empower materials scientists to design materials with tailored characteristics, improved performance, and enhanced functionality, thereby expanding scientific knowledge and technological progress. This research paper presents the synthesis of two new metal-organic material-based films using the cathodic electrodeposition method. In contrast with the anodic deposition method, the cathodic deposition method offers the advantage of using non-metal electrode substrates and various metal ions, a unique aspect not yet fully explored. The study investigates the effects of linker length using 2,5-dihydroxyterephthalic acid (DOBDC) and 3,3'-dihydroxybiphenyl-4,4'-dicarboxylic acid (BPP) as organic linkers and iron(III) as the metal node for the structures. The films' electrochemical behaviour, characterisation through techniques like infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-Ray powder diffraction and grazing-Incidence small-angle X-ray scattering and particle-induced X-ray emission, as well as results from cyclic voltammetry studies, are discussed. The films were found to be nearly amorphous with specific grain sizes, revealing heterogeneity in composition and thickness. The unique synthesis method and comprehensive characterisation offer insights into the potential of electrosynthesis for designing functional materials and encourage further exploration of various synthesis conditions and metal ions. | Sara Realista; Ana R. Reis; Duarte Borralho; Victoria Corregidor; Luís C. Alves; Sérgio Magalhães; Telmo Nunes; Ana S. Viana; João Pires; Ana M. Ferraria; Ana M. Botelho do Rego; Paulo N. Martinho | Inorganic Chemistry; Electrochemistry; Solid State Chemistry; Spectroscopy (Inorg.); Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/661cf41a91aefa6ce198164c/original/electrosynthesis-of-iron-based-metal-organic-materials-with-bis-salicylic-acid-derivatives.pdf |
6765531881d2151a025c5efe | 10.26434/chemrxiv-2024-lx6m1 | Finding Potentially Erroneous Entries in METLIN SMRT | Background:
METLIN SMRT is a widely-used dataset of retention times for high-performance liquid chromatography (HPLC). Besides direct application it is used for training models aimed at predicting retention times in HPLC. Although there are quite a number of articles featuring METLIN SMRT, the pipelines used for filtering from errors are either simplistic or nonexistent. Two more datasets of HPLC retention times - RepoRT and MCMRT - have emerged recently. RepoRT maintainers used a 10-fold cross-validation strategy with gradient boosting models to validate retention times in the database. MCMRT maintainers suggested a projection method for transferring retention times from one chromatographic method to another, but there is no information about applying the method for data validation. Therefore, a reliable method for filtering potentially erroneous entries is still required.
Results:
An approach to filter potentially erroneous entries, as suggested in our earlier work for a database of gas chromatography retention indexes, was repurposed for METLIN SMRT using five predictive models (GNN, CNN, FCFP, FCD, and CatBoost). The retention times were predicted for the whole dataset using a 5-fold cross-validation strategy. Entries with retention times differing significantly from the predictions (bottom 5%) were flagged with a “yellow card”. This procedure was repeated for each model, leading to obtaining a group containing 1544 entries (about 2% of the dataset) with 5 “yellow cards”. These entries were considered potentially erroneous, as anomalous behavior was observed in the analyzed trends (with the increasing number of “yellow cards”) for both the size of each group and the standard deviation of the predictions.
Significance:
The previously proposed filtering approach was expanded to a retention time database, enabling finding potentially erroneous entries in METLIN SMRT. This work demonstrates the viability of the approach and its potential to improve the quality of other large-scale chromatography-related databases both for machine learning and experimental use. | Mikhail Khrisanfov; Dmitriy Matyushin; Andrey Samokhin | Theoretical and Computational Chemistry; Analytical Chemistry; Chemoinformatics; Separation Science; Machine Learning | CC BY 4.0 | CHEMRXIV | 2024-12-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6765531881d2151a025c5efe/original/finding-potentially-erroneous-entries-in-metlin-smrt.pdf |
67225b9bf9980725cf97b44a | 10.26434/chemrxiv-2024-2bps8 | Probing Metal-Organic Framework Stoichiometry Using Quantitative NMR and TGA | Metal-organic frameworks are crystalline materials that do not always have a perfect stoichiometry, due to the presence of defects, modulators or mixed linkers. A common approach to quantify these defects is to define a value for ‘missing linkers’, typically done by thermogravimetric analysis (TGA). We propose the use of the (metal oxide) residue of TGA to quantify the metal content in combination with quantitative NMR spectroscopy of a digested sample for linker quantification. We demonstrate this simple concept for three examples, MAF-6, ZIF-8 and MOF-5. | Flip de Jong; Tim Balcaen; Giel Arnauts; Leen Boullart; Alice Suarez Kahan; Johan Hofkens; Rob Ameloot; Mark Van der Auweraer; Gert Steurs | Physical Chemistry; Analytical Chemistry; Analytical Chemistry - General; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-11-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67225b9bf9980725cf97b44a/original/probing-metal-organic-framework-stoichiometry-using-quantitative-nmr-and-tga.pdf |
6672b8ae01103d79c59082dd | 10.26434/chemrxiv-2024-p8hbw | Synergistic Energy-Harvesting Coumarin Photocages Enabling Lysosomal pH Rescue | Light-triggered molecular tools releasing bioactive actuators with high spatial and temporal control have prompted significant advances in optobiology. Such probes however require high levels of photosensitivity at biocompatible wavelengths to trigger a biological response safely and efficiently. Here, we propose synergistic, multi-chromophoric, water-soluble systems in which quadrupolar antennas sensitize a coumarinyl photocage, delivering a carboxylic acid payload upon one-photon (visible) or two-photon excitation in the biological transparency near-infrared (NIR) window. Strikingly, the molecular design promotes a 50 % increase in photo-cleavage quantum yield, leading to record photosensitivity for NIR-triggered release of acetic acid. We further demonstrated that these molecular tools efficiently rescue impaired lysosomal pH in a genetic cellular model of Parkinson’s disease. These photoactivated tools are therefore promising candidates for the phototherapeutic management of neurodegenerative diseases | Maxime Klausen; Victor Dubois; Jean-Baptiste Verlhac; Benjamin Dehay; Mireille BLANCHARD-DESCE | Physical Chemistry; Biological and Medicinal Chemistry; Drug Discovery and Drug Delivery Systems; Photochemistry (Physical Chem.); Physical and Chemical Properties | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6672b8ae01103d79c59082dd/original/synergistic-energy-harvesting-coumarin-photocages-enabling-lysosomal-p-h-rescue.pdf |
6345938e2e6e7cdea4575dd1 | 10.26434/chemrxiv-2022-v9cz6 | Bioactive hard protein coronas on poly(propylene sulfone) surfaces enable mast cell nanotherapy | Contact between nanomaterials and biomolecules such as serum proteins leads to “soft” or “hard” corona formation via dynamic or irreversible adsorption, respectively. While soft coronas of antibodies can temporarily retain the ability for immunological recognition, preserving protein function within hard coronas has remained an elusive goal due to the unfolding of protein at the nano-bio interface. Here, we show that poly(propylene sulfone) nanoparticles efficiently and stably adsorb proteins, unexpectedly forming bioactive hard coronas using a facile methodology. This process is permitted by site-specific hydrophobic-hydrophobic interactions between nanoparticle surfaces and proteins, allowing stable simultaneous pre-adsorption of multiple proteins such as enzymes and antibodies. For therapeutic validation, a nanotherapy for enhanced antibody-based targeting of mast cells and inhibition of anaphylaxis was demonstrated in a humanized mouse model. Protein immobilization on the poly(propylene sulfone) surface therefore provides a simple and rapid platform for the design, fabrication, and optimization of bioactive and targeted nanomedicines. | Fanfan Du; Clayton Rische; Yang Li; Michael Vincent; Yuan Qian; Simseok Yuk; Sultan Almunif; Bruce Bochner; Baofu Qiao; Evan Scott | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Nanoscience; Nanostructured Materials - Nanoscience; Bioengineering and Biotechnology; Computational Chemistry and Modeling | CC BY NC 4.0 | CHEMRXIV | 2022-10-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6345938e2e6e7cdea4575dd1/original/bioactive-hard-protein-coronas-on-poly-propylene-sulfone-surfaces-enable-mast-cell-nanotherapy.pdf |
66b3bba45101a2ffa86ff014 | 10.26434/chemrxiv-2024-9h3mn | Robust catalyst assessment for the electrocatalytic nitrate reduction reaction | The electrochemical nitrate reduction reaction (NO3RR) shows great promise for the distributed conversion of waste nitrate to ammonia. We highlight complexities of the reaction mechanism and possible waste feedstocks, and advocate best practices for robust measurement of catalyst activity, selectivity, and Faradaic efficiency in this burgeoning field. While fundamental studies of the reaction mechanism and environment are still needed, rigorous performance assessment in well-defined conditions will best enable catalyst design. Progress will be most dynamic and responsive with shared community standards that enable comparison between groups while reflecting the complexity of possible feedstocks | Devesh Kumar Pathak; Rajkumar Jana; Ruth Bello; Kelly White; Kelsey A Stoerzinger | Catalysis; Electrocatalysis | CC BY 4.0 | CHEMRXIV | 2024-08-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66b3bba45101a2ffa86ff014/original/robust-catalyst-assessment-for-the-electrocatalytic-nitrate-reduction-reaction.pdf |
60c73fa6842e651739db1b5b | 10.26434/chemrxiv.7471202.v1 | Control of Pharmaceutical Cocrystal Polymorphism on Various Scales by Mechanochemistry: Transfer from the Laboratory Batch- to the Large-Scale Extrusion Processing | <p>We demonstrate a controllable mechanochemical synthesis of
cocrystal polymorphs of ascorbic acid (vitamin C) and nicotinamide (vitamin B3)
on different scales and without using bulk solvents. Next to the previously
described polymorph of the 1:1 cocrystal, which is one of the first cocrystals
approved for human consumption, we report here a new, thermodynamically more
stable polymorph detected during in situ synchrotron powder X-ray diffraction
monitoring of milling reactions. The new polymorph is currently available
exclusively by mechanochemical synthesis, and its crystal structure was
determined from powder X-ray diffraction data. Laboratory in situ monitoring by
Raman spectroscopy provided direct insight into the cocrystals formation and
was further used to optimize the manufacturing procedure. Sub-gram synthesis
using laboratory mixer mill was transferred to the 10 g scale on a planetary
ball mill and continuous manufacturing using a twin-screw extruder. Both
cocrystal polymorphs perform excellently in tableting, thus alleviating the
notoriously poor compactible properties of vitamin C, while the mechanochemical
cocrystallization does not harm its antioxidant properties.<b></b></p> | Tomislav Stolar; Stipe Lukin; Martina Tireli; Irena Sović; Bahar Karadeniz; Irena Kereković; Gordana Matijašić; Matija Gretić; Zvonimir Katančić; Igor Dejanović; Marco Di Michiel; Ivan Halasz; Krunoslav Užarević | Industrial Manufacturing; Pharmaceutical Industry; Process Control; Physical and Chemical Properties | CC BY NC ND 4.0 | CHEMRXIV | 2018-12-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73fa6842e651739db1b5b/original/control-of-pharmaceutical-cocrystal-polymorphism-on-various-scales-by-mechanochemistry-transfer-from-the-laboratory-batch-to-the-large-scale-extrusion-processing.pdf |
6538690087198ede0735c524 | 10.26434/chemrxiv-2023-1mgs8-v2 | Toward Three-dimensionally Ordered Nanoporous Graphene Materials: Template Synthesis, Structure, and Applications | Precise template synthesis will realize three-dimensionally ordered nanoporous graphenes (NPGs) with a spatially controlled seamless graphene structure and fewer edges. These structural features result in superelastic nature, high electrochemical stability, high electrical conductivity, and fast diffusion of gases and ions at the same time. Such innovative 3D graphene materials are conducive to solving energy-related issues for better future. To further improve the attractive properties of NPGs, we review the template synthesis and its mechanism by chemical vapor deposition of hydrocarbons, analysis of nanoporous graphene structure, and applications in electrochemical and mechanical devices. | Masanori Yamamoto; Shunsuke Goto; Rui Tang; Kaoru Yamazaki | Materials Science; Nanoscience; Carbon-based Materials; Nanostructured Materials - Materials; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2023-11-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6538690087198ede0735c524/original/toward-three-dimensionally-ordered-nanoporous-graphene-materials-template-synthesis-structure-and-applications.pdf |
6690dcc8c9c6a5c07a0fb78a | 10.26434/chemrxiv-2024-k00w2 | Contrast-Enhanced Imaging of Carbon Fiber Composites using Hafnium Oxide Nanocrystals | Carbon fiber reinforced polymers (CFRPs) are of utmost importance in high-performance structural applications (e.g. aerospace, automotive, wind energy), but their behaviour is not fully understood. Damage propagation models need to take into account the type, geometry and orientation of a multitude of failure mechanisms and defects. Micro-Computed Tomography (micro-CT) data could provide the necessary input for these models, but the poor contrast between the carbon fibers and the polymer matrix does not allow automatic geometry extraction. To overcome this issue, hafnium oxide nanocrystals (HfO2 NCs) were introduced as CT contrast agents to the polymer matrix to provide the required contrast. To ensure a homogeneous and stable dispersion of the NCs in the epoxy resin, a bisphosphonic acid ligand consisting of ethylene glycol oligomer segments is used. The NCs do not significantly alter important parameters such as matrix stiffness, viscosity, glass transition temperature and curing time, enabling them to be implemented without having to alter current composite resin infusion methods. NC-doped CFRPs with 5 and 10 m% of HfO2 NCs added show a drastic improvement in CT contrast, allowing for segmentation of the carbon fiber tows and visualization of micrometer-scale cracks. The contrast-enhanced HfO2 NC-doped composites thereby enable the validation of damage models by accurate micro-CT data. | Eline Goossens; Ives De Baere; Yuriy Sinchuk; Evert Dhaene; John De Vos; Matthieu Boone; Jonathan De Roo; Isabel Van Driessche; Wim Van Paepegem; Klaartje De Buysser | Polymer Science; Nanoscience; Polymer blends; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6690dcc8c9c6a5c07a0fb78a/original/contrast-enhanced-imaging-of-carbon-fiber-composites-using-hafnium-oxide-nanocrystals.pdf |
65b4d8ede9ebbb4db9164866 | 10.26434/chemrxiv-2023-2km2q-v2 | Synthesis and Structure of Vacancy-Ordered Perovskite Ba6Ta2Na2X2O17 (X = P, V): Significance of Structural Model Selection on Discovered Compounds | Ba6Ru2Na2X2O17 (X = P, V) with vacancy-ordered 12H-type hexagonal perovskite with a (c’cchcc)2 stacking sequence of [BaO3]c, [BaO3]h and [BaO2]c’ layers, where c and h represent a cubic and hexagonal stacking sequence, were previously reported by Quarez et al. in 2003. They also synthesized Ba6Ta2Na2V2O17, but the structural refinement was absent. Very recently, Szymanski et al. reported 41 new compounds, including 12H-type Ba6Ta2Na2V2O17, using large-scale ab initio phase-stability data from the Materials Project and Google DeepMind. But their structural refinement was very poor. Here, we report synthesis and structure of Ba6Ta2Na2V2O17, which does not have 12H-type structure, but has a vacancy-ordered 6C-type hexagonal perovskite with a (c’ccccc) stacking sequence of [BaO3]c and [BaO2]c’ layers. We also report the phosphite analog Ba6Ta2Na2P2O17 as a new compound. We claim an importance of careful structural characterization on newly discovered compounds; otherwise, the database constructed will lose credibility. | Takafumi Yamamoto; Yuya Otsubo; Teppei Nagase; Taiki Kosuge; Masaki Azuma | Materials Science; Inorganic Chemistry; Ceramics; Solid State Chemistry; Materials Chemistry; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65b4d8ede9ebbb4db9164866/original/synthesis-and-structure-of-vacancy-ordered-perovskite-ba6ta2na2x2o17-x-p-v-significance-of-structural-model-selection-on-discovered-compounds.pdf |
60c73d92bb8c1a57b53d979d | 10.26434/chemrxiv.5930644.v1 | Small-Molecule (Micro)arrays for Sensitive Multiplex Metabolites Detection by Surface Plasmon Resonance Imaging | <div>
<div>
<div>
<p>Small-molecule (micro)arrays were developed to measure three
metabolites simultaneously by surface plasmon resonance
imaging for the first time. To tackle the low sensitivity challenge
associated with small molecule detection, antibodies were
employed as the signal amplifiers. This work demonstrates both
inhibition and displacement formats are applicable for sensitive
multiplex metabolites detection.
</p>
</div>
</div>
</div> | Yong Cao; Mark T. McDermott | Analytical Chemistry - General; Biochemical Analysis; Biophysics | CC BY NC ND 4.0 | CHEMRXIV | 1970-01-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73d92bb8c1a57b53d979d/original/small-molecule-micro-arrays-for-sensitive-multiplex-metabolites-detection-by-surface-plasmon-resonance-imaging.pdf |
61707d99913a7405f8617ef7 | 10.26434/chemrxiv-2021-cdmpf | Combinatorial Polycation Synthesis and Causal Machine Learning Reveal Divergent Polymer Design Rules for Effective pDNA and Ribonucleoprotein Delivery | The development of polymers that can replace engineered viral vectors in clinical gene therapy has proven elusive despite the vast portfolios of multifunctional polymers generated by advances in polymer synthesis. Functional delivery of payloads such as plasmids (pDNA) and ribonucleoproteins (RNP) to various cellular populations and tissue types requires design precision. Here, we systematically screen a combinatorially designed library of 43 well-defined polymers, ultimately identifying a lead polycationic vehicle (P38) for efficient pDNA delivery. Further, we demonstrate the versatility of P38 in co-delivering spCas9 RNP and pDNA payloads to mediate homology directed repair as well as in facilitating efficient pDNA delivery in ARPE-19 cells. P38 achieves nuclear import of pDNA and eludes lysosomal processing far more effectively than a structural analog that does not deliver pDNA as efficiently. To reveal the physicochemical drivers of P38's gene delivery performance, SHapley Additive exPlanations (SHAP) are computed for nine polyplex features, and a causal model is applied to evaluate the average treatment effect of the most important features selected by SHAP. Our machine learning interpretability and causal inference approach derives structure-function relationships underlying delivery efficiency, polyplex uptake, and cellular viability, and probes the overlap in polymer design criteria between RNP and pDNA payloads. Together, combinatorial polymer synthesis, parallelized biological screening, and machine learning establish that pDNA delivery demands careful tuning of polycation protonation equilibria while RNP payloads are delivered most efficaciously by polymers that deprotonate cooperatively via hydrophobic interactions. These payload-specific design guidelines will inform further design of bespoke polymers for specific therapeutic contexts. | Ramya Kumar; Ngoc Le; Felipe Oviedo; Mary E. Brown; Theresa M. Reineke | Biological and Medicinal Chemistry; Polymer Science; Nanoscience; Drug delivery systems; Polyelectrolytes - Polymers | CC BY NC ND 4.0 | CHEMRXIV | 2021-10-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61707d99913a7405f8617ef7/original/combinatorial-polycation-synthesis-and-causal-machine-learning-reveal-divergent-polymer-design-rules-for-effective-p-dna-and-ribonucleoprotein-delivery.pdf |
64fd5bcdb6ab98a41c2d608d | 10.26434/chemrxiv-2023-4f8pn | Synthesis and fabrication of ultrafiltration membranes from homo and blend polymers of novel combination of cyclic amides/ imides to norbornene/ oxonorbornene; shift from classic oligomers to high performing polymer materials. | Controlled release of active chlorine into the water system through membrane bound disinfectant, prevention of biofilm formation at the membrane surface and killing of antibiotic resistant bacteria were the study objectives that were accomplished in presented work. Cyclic amines/amides/imides are effective precursor of N-halogenated amines/amides/imides. Such N-halogenated compounds are found to be effective against antibiotic resistant bacteria such as, E. coli and S. aureus. Henceforth cyanuric acid and 5,5-dimethyl hydantoin were selected as representative precursor of such amide/imides that could be halogenated and provide antimicrobial performance. The polymer PES was introduced with side chain of primary amine. Further this primary amine was converted to secondary amine with novel modification containing cyanuric chloride. It was further modified to cyanuric acid as a desired precursor of N-halamide/imide. The PES-modified -cyanuric acid (PESmCA) was characterized using IR, NMR, XRD and SEM. While two novel monomers containing hydantoin as a branch extending from the ethyl group chain; belonging to norbornene dicarboximide and oxonorbornene dicarboximide, were successfully synthesize and characterized using IR, NMR and HRMS techniques. Further these monomers were polymerized via ring opening metathesis polymerization reaction into novel polymers of P(NDH) and P(ONDH). The polymer’s olefinic bonds were saturated to s-P(NDH) and s-P(ONDH). The unsaturated and saturated polymers were characterized through IR, NMR, and SLS techniques. The saturated polymers and the modified PES were fabricated into membranes and characterized via SEM and contact angle measurement. The membrane performance tests were conducted using pure water permeance and BSA protein rejection tests. The membranes were chlorinated and rinsed to remove adsorbed active chlorine. The rinsed membranes were characterized with IR providing respective N-Cl peak in range of 721-719 cm-1. The unwanted chlorine release into the water assembly was not observed provided that the respective polymers had covalently stable cyclic N-Cl moieties. Membranes were challenged against 106CFU/ml of bacteria (E.coli and S.aureus) in static agar test and dead end filtration tests. The membranes provided 100% inhibition of bacteria E. coli and S. aureus upon surface contact in agar plate test. The respective membranes were also suitable for dead end filtration pressure assisted bacterial flow test. The test provided 99-100 % kill of both bacteria. These N-halamide/imide novel polymer and modified polymer systems were efficiently chlorinated through repeated cycles.
Keywords: Modified PES, norbornene polymers, oxonorbornene polymers, ROMP, controlled release of active chlorine, biofilm prevention, inhibition of antibiotic resistant bacteria, phase inversion, UF membranes.
| Sadia Tul Munna | Organic Chemistry; Polymer Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-11-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64fd5bcdb6ab98a41c2d608d/original/synthesis-and-fabrication-of-ultrafiltration-membranes-from-homo-and-blend-polymers-of-novel-combination-of-cyclic-amides-imides-to-norbornene-oxonorbornene-shift-from-classic-oligomers-to-high-performing-polymer-materials.pdf |
60c74b550f50db88d9396be4 | 10.26434/chemrxiv.12320033.v1 | Chemical Trends in the Lattice Thermal Conductivity of Li(Ni,Mn,Co)O<sub>2</sub> (NMC) Battery Cathodes | <div>While the transport of ions and electrons in conventional Li-ion battery cathode</div><div>materials is well understood, our knowledge of the phonon (heat) transport is still in its</div><div>infancy. We present a first-principles theoretical investigation of the chemical trends</div><div>in the phonon frequency dispersion, mode lifetimes, and thermal conductivity in the</div><div>series of layered lithium transition-metal oxides Li(NixMnyCoz)O2 (x+y+z = 1). The</div><div>oxidation and spin states of the transition metal cations are found to strongly influence</div><div>the structural dynamics. Calculations of the thermal conductivity show that LiCoO2</div><div>has highest average conductivity of 45.9W m−1 K−1 at T = 300 K and the largest</div><div>anisotropy, followed by LiMnO2 with 8.9W m−1 K−1, and LiNiO2 with 6.0W m−1 K−1</div><div>The much lower thermal conductivity of LiMnO2 and LiNiO2 is found to be due to 1–2 orders of magnitude shorter phonon lifetimes. We further model the properties of binary and ternary transition metal combinations and show that the thermal conductivity of NMC is suppressed with decreasing Co content and increasing Ni/Mn</div><div>content. The thermal conductivity of commercial NMC622 (LiNi0.6Mn0.2Co0.2O2) and NMC111 (LiNi0.33Mn0.33Co0.33O2) compositions are substantially larger than NMC811LiNi0.8Mn0.1Co0.1O2). These results serve as a guide to ongoing work on the designof multi-component battery electrodes with more effective thermal management.</div><div><br /></div> | Hui YANG; Christopher Savory; Benjamin Morgan; David Scanlon; Jonathan Skelton; Aron Walsh | Solid State Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74b550f50db88d9396be4/original/chemical-trends-in-the-lattice-thermal-conductivity-of-li-ni-mn-co-o-sub-2-sub-nmc-battery-cathodes.pdf |
64f8361d3fdae147fa9922c9 | 10.26434/chemrxiv-2023-jzd4r | NiGraf: A new nickel-based molecularly doped metal for enhanced water electrolysis | Graphene oxide was 3D entrapped in nickel nanoparticles and the resulting nanostructured material applied as electrocatalyst in both hydrogen and oxygen evolution reactions at room temperature. This establishes a completely new class of catalytic materials, dubbed herein “NiGraf”, which is highly promising towards enhanced alkaline water electrolysis. | Mario Pagliaro; Maria V. Pagliaro; Rocco Caliandro; Cinzia Giannini; Rosaria Ciriminna; Alessandro Lavacchi | Catalysis; Electrocatalysis; Nanocatalysis - Reactions & Mechanisms; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-09-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64f8361d3fdae147fa9922c9/original/ni-graf-a-new-nickel-based-molecularly-doped-metal-for-enhanced-water-electrolysis.pdf |
60c744b9ee301c3723c791ba | 10.26434/chemrxiv.9892067.v1 | Covalently Linked Donor-Acceptor Dyad for Efficient Single Material Organic Solar Cells | A novel covalently linked donor-acceptor dyad comprising a dithienopyrrol-based oligomeric donor and a fullerene acceptor was synthesized and characterized. The concomitant effect of favorable optoelectronic properties, energy levels of the frontier orbitals, and ambipolar charge transport enabled the application of the dyad in simplified solution-processed single material organic solar cells reaching a power conversion efficiency of 3.4%.<br /><br /><br /> | Sebastian Lucas; Tim Leydecker; P. Samorì; Elena Mena Osteritz; Peter Baeuerle | Oligomers | CC BY NC ND 4.0 | CHEMRXIV | 2019-09-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c744b9ee301c3723c791ba/original/covalently-linked-donor-acceptor-dyad-for-efficient-single-material-organic-solar-cells.pdf |
60c746fb702a9b7d2718acdb | 10.26434/chemrxiv.11457909.v1 | Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Synthesis of β-Lactams | Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates due to their extreme strain and kinetic instability. Herein, we report the enantioselective synthesis of 1-sulfonylcyclopropanols as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, via α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as electrophilic oxygen source. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone, highlighting the modular nature of these precursors and the potential for their widespread adoption as synthetic intermediates. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines acting here as nitrene equivalents, leading to the efficient formation of chiral β-lactam derivatives. | Christopher M. Poteat; Yujin Jang; Myunggi Jung; John D. Johnson; Rachel G. Williams; Vincent Lindsay | Organic Synthesis and Reactions | CC BY 4.0 | CHEMRXIV | 2019-12-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c746fb702a9b7d2718acdb/original/enantioselective-synthesis-of-cyclopropanone-equivalents-and-application-to-the-synthesis-of-lactams.pdf |
65835949e9ebbb4db95faf26 | 10.26434/chemrxiv-2023-x1hlv | Microfluidic-driven short peptides hydrogels with optical waveguiding property | Soft photonic elements with optical waveguiding ability based on biocompatible hydrogels have become increasingly important in optical techniques for medical diagnosis and phototherapy, among others. Supramolecular hydrogels based on peptides with interesting optical properties are rarely reported and explored. Although robust crystals based on short peptides have shown optical waveguiding capabilities, their rigidity is the main issue to overcome in the quest for soft biocompatible materials. Here, we report on a microfluidic-assisted formation of a heterochiral short peptide hydrogel that exhibit active optical waveguiding property thanks to the incorporation of two different dyes, Thioflavin T and Rhodamine B, in the hydrogel structure. Using our microfluidic platform, different parameters such as concentration of peptide, type of dye and its concentration, and flow rate have been rapidly explored, with remarkable low reagents consumption. In this way, it was possible to develop peptide hydrogel waveguides with good optical loss values, modulating the emission in diverse spectral regions. The use of microfluidics to prepare these hydrogels makes possible the preparation of structures of high length-to-diameter aspect ratio, which otherwise are hard to devise from bulk conditions. Overall, this work broadens the use of supramolecular self-assembly of peptides to create functional materials with additional versatility to polymeric hydrogels, thanks to the possibility of tuning structure by changing amino acids sequence. Additionally, the optical properties can be easily modulated by quick optimization of experimental parameters via microfluidic technology. | Ana M. Garcia; Juan A. Garcia-Romero; Sara H. Mejias; Pilar Prieto; Vittorio Saggiomo; Aldrik H. Velders; M. Laura Soriano; Victor Ruiz-Díez; Juan Cabanillas-González; M. Victoria Gomez | Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-12-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65835949e9ebbb4db95faf26/original/microfluidic-driven-short-peptides-hydrogels-with-optical-waveguiding-property.pdf |
67c1f0bb81d2151a02776911 | 10.26434/chemrxiv-2025-3cql6 | Benchmarking Mechanical Properties of 3D Printed Elastomeric Microstructures | The characterization of mechanical properties in soft 3D printed materials at the microscale remains a significant challenge due to the lack of standardized methodologies. To address this issue, a microscale nanoindentation protocol for elastomeric 3D printed microstructures is developed, optimized, and benchmarked. Herein, a conospherical indenter tip (r = 10.26 µm), a modified trapezoidal displacement profile with lift-off segments to capture adhesion interactions, and the nano-Johnson-Kendall-Roberts model for data analysis is employed. The protocol is optimized and verified using four newly developed PDMS-based inks for two-photon 3D laser printing. The results are compared to a state-of-the-art literature protocol that uses a Berkovich tip and the Oliver-Pharr model. It is shown that adhesion forces play a significant role in mechanical properties overestimation, showing differences of up to 80% between the different protocols. This study highlights the importance of carefully selecting characterization protocol to yield comparable results between studies. By providing a standardized protocol, it paves the way for straightforward and accurate characterization of mechanical properties in soft 3D printed materials at the microscale. | Or Eivgi; Clara Vazquez-Martel; Jaroslav Lukeš; Eva Blasco | Materials Science; Polymer Science | CC BY 4.0 | CHEMRXIV | 2025-03-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c1f0bb81d2151a02776911/original/benchmarking-mechanical-properties-of-3d-printed-elastomeric-microstructures.pdf |
67b7a3066dde43c908c1a82a | 10.26434/chemrxiv-2025-pq5g7 | Rapid Room-Temperature Sulfidation of Commercial FeNiCo Alloy for Efficient Oxygen Evolution Reaction | Although various highly active transition metal-based electrocatalysts have been identified for the anodic oxygen evolution reaction (OER) for alkaline water electrolysis, the necessity of a binder to coat electrocatalysts onto conductive supports affects the overall durability. Thus, developing a highly active, durable, and binder-free anode is beneficial for advancing alkaline water electrolysis for broader applications. This study presents a new yet effective surface sulfidation method for converting commercial FeNiCo alloy, Kovar, into highly active, stable, and binder-free OER electrodes. This surface sulfidation step leads to surface enrichment of Ni, higher oxidation states of Ni and Fe, and sulfur incorporation into lattice oxygen, which enhances the formation of (oxy)hydroxide and modulates the binding energy of *OH intermediate species. Hence, the surface sulfidized Kovar electrode demonstrated a significant enhancement in OER performance, with an overpotential as low as 261 mV at 10 mA/cm2 (compared to 345 mV at 10 mA/cm2 for as-received Kovar), a Tafel slope of ~ 40 mV/dec, and robust stability over 120 hours in 1 M KOH. Thus, our surface sulfidation technique facilitates using commercial alloys as self-sufficient anodes without binders and catalysts for alkaline water electrolysis. | Dongjae Kong; Jihyun Baek; Sungsoon Kim; Xiaolin Zheng | Catalysis; Electrocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2025-02-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67b7a3066dde43c908c1a82a/original/rapid-room-temperature-sulfidation-of-commercial-fe-ni-co-alloy-for-efficient-oxygen-evolution-reaction.pdf |
64209d1091074bccd052c0a6 | 10.26434/chemrxiv-2023-mjlb4 | Expanding Lignin Thermal Property Space by Fractionation and Covalent Modification | To fully exploit kraft lignin’s potential in material applications, we need to achieve tight control over those key physicochemical lignin parameters that ultimately determine, and serve as proxy for, the properties of lignin-derived materials. Here, we show that fractionation combined with systematic (incremental) modification provides a powerful strategy to expand and controllably tailor lignin property space. In particular, the glass transition temperature (Tg) of a typical kraft lignin could be tuned over a remarkable and unprecedented 213 oC. Remarkably, for all fractions the Tg proved to be highly linearly correlated with the degree of derivatisation by allylation, offering such tight control over the Tg of the lignin and ultimately the ability to ‘dial-in’ this key property. Importantly, such control over this proxy parameter indeed translated well to lignin-based thiol-ene thermosetting films, which Tg ‘s thus covered a range from 2 - 124 oC. This proof of concept suggests this approach to be a powerful and generalisable one, allowing a biorefinery or downstream operation to consciously and reliably tailor lignins to predictable specifications which fit their desired application. | Luke Riddell; Floris Enthoven; Jean-Pierre Lindner; Florian Meirer; Pieter Bruijnincx | Analytical Chemistry; Polymer Science; Biopolymers; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64209d1091074bccd052c0a6/original/expanding-lignin-thermal-property-space-by-fractionation-and-covalent-modification.pdf |
67357842f9980725cf2052be | 10.26434/chemrxiv-2024-6q6q5 | Reversible ppt-Level Detection of Perfluorooctane Sulfonic Acid in Tap Water using Field-Effect Transistor Sensors | Widespread, persistent, and toxic per- and polyfluoroalkyl substances (PFAS) pose a major threat to both water systems and human health. Current PFAS detection methods are relatively expensive, slow, and complex. To combat PFAS contamination and meet increasingly stringent regulations of PFAS in drinking water, the development of highly sensitive and selective PFAS sensing techniques is urgently needed. Herein, we present an ultrasensitive sensing platform for perfluorooctane sulfonic acid (PFOS) detection in tap water with a reporting limit (~250 ppq) lower than the maximum contaminant level (4 ppt) set by the U.S. Environmental Protection Agency, using remote gate field-effect transistor (RGFET) sensors featuring β-cyclodextrin (β-CD)-modified reduced graphene oxide as the sensing membrane. The sensor exhibits excellent selectivity against common inorganic ions (e.g., Na+, K+, Ca2+, Cl-, HPO42-, SO42- ) and select organic pollutants (e.g., trichloroacetic acid) in tap water. Importantly, the reversible and rapid response (< 2 min) indicates the potential of RGFET for continuous inline monitoring of PFAS. Quartz crystal microbalance results emphasize the important roles of both analyte adsorption and charge properties of analytes and buffers in generating sensing signals. The binding nature between β-CD probe and PFOS or interferent molecules, as well as the spatially resolved selectivity revealed by molecular dynamics simulations, suggest rational probe engineering strategies for future selective capture probe design. | Yuqin Wang; Hyun-June Jang; Max Topel; Siva Dasetty; Yining Liu; Mohamed Ateia; Aaron Tam; Vepa Rozyyev; Ellie Ouyang; Wen Zhuang; Haihui Pu; Sang Soo Lee; Jeffrey Elam; Andrew Ferguson; Seth Darling; Junhong Chen | Materials Science; Nanoscience; Earth, Space, and Environmental Chemistry; Carbon-based Materials; Environmental Science; Nanodevices | CC BY NC 4.0 | CHEMRXIV | 2024-11-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67357842f9980725cf2052be/original/reversible-ppt-level-detection-of-perfluorooctane-sulfonic-acid-in-tap-water-using-field-effect-transistor-sensors.pdf |
60c74188842e65e6bfdb1edd | 10.26434/chemrxiv.8061650.v1 | Anion Distribution, Structural Distortion, and Symmetry-Driven Optical Band Gap Bowing of Mixed Halide Cs2SnX6 Vacancy Ordered Double Perovskites | Mixed anion compounds in the Fm-3m vacancy ordered perovskite structure were synthesised and characterised experimentally and computationally with a focus on compounds where A = Cs+. Pure anion Cs<sub>2</sub>SnX<sub>6</sub> compounds were formed with X = Cl, Br and I using a room temperature solution phase method. Mixed anion compounds were formed as solid solutions of Cs<sub>2</sub>SnCl<sub>6</sub> and Cs<sub>2</sub>SnBr<sub>6</sub> and a second series from Cs<sub>2</sub>SnBr<sub>6</sub> and Cs<sub>2</sub>SnI<sub>6</sub>. Single phase structures formed across the entirety of both composition series, with no evidence of long range anion ordering observed by diffraction. A distortion of the cubic A2BX6 structure was identified in which the spacing of the BX6 octahedra changes to accommodate the A site cation without reduction of overall symmetry. Optical band gap values varied with anion composition between 4.89 eV in Cs<sub>2</sub>SnCl<sub>6 </sub>to 1.35 eV in Cs<sub>2</sub>SnI<sub>6</sub>, but proved highly non-linear with changes in composition. In mixed halide compounds it was found that lower energy optical transitions appeared that were not present in the pure halide compounds, and this could be attributed to lowering of the local symmetry within the tin halide octahedra. The electronic structure was characterised by photoemission spectroscopy, and Raman spectroscopy revealed vibrational modes in the mixed halide compounds that could be assigned to particular mixed halide octahedra. This analysis was used to determine the distribution of octahedra types in mixed anion compounds, which was found to be consistent with a near-random distribution of halide anions throughout the structure, although some deviations from random halide distribution were noted in mixed iodide-bromide compounds, where the larger iodide anions preferentially adopted trans configurations. | Maham Karim; Alex Ganose; Laura Pieters; Winnie Leung; Jess Wade; Lina Zhang; David Scanlon; Robert Palgrave | Solid State Chemistry; Spectroscopy (Inorg.); Theory - Inorganic; Photovoltaics; Structure | CC BY NC ND 4.0 | CHEMRXIV | 2019-05-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74188842e65e6bfdb1edd/original/anion-distribution-structural-distortion-and-symmetry-driven-optical-band-gap-bowing-of-mixed-halide-cs2sn-x6-vacancy-ordered-double-perovskites.pdf |
60d4d865e21133844ce09e81 | 10.26434/chemrxiv-2021-czw58 | Molecular Chirality and Cloud Activation Potentials of Dimeric α-Pinene Oxidation Products | The surface activity of ten atmospherically relevant α-pinene-derived dimers having varying terminal functional groups and backbone stereochemistry is reported. We find ~10 percent differences in surface activity between diastereomers of the same dimer, demonstrating that surface activity depends upon backbone stereochemistry. Octanol¬–water (KOW) and octanol–ammonium sulfate partitioning coefficient (KOAS) measurements of our standards align well with the surface activity measurements, with the more surface-active dimers exhibiting increased hydrophobicity. Our findings establish a link between molecular chirality and cloud activation potential of secondary organic aerosol particles. Given the diurnal variations in enantiomeric excess of biogenic emissions, possible contributions of such a link to biosphere:atmosphere feedbacks as well as aerosol particle viscosity and phase separation are discussed. | Regan Thomson; Franz Geiger; Aleia Bellcross; Ariana Bé | Physical Chemistry; Organic Chemistry; Earth, Space, and Environmental Chemistry; Organic Synthesis and Reactions; Stereochemistry; Atmospheric Chemistry | CC BY 4.0 | CHEMRXIV | 2021-06-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60d4d865e21133844ce09e81/original/molecular-chirality-and-cloud-activation-potentials-of-dimeric-pinene-oxidation-products.pdf |
63d0a1f21fe1425ae858c3a6 | 10.26434/chemrxiv-2023-ncl51 | Exploring activity landscapes with extended similarity: is Tanimoto enough? | Understanding structure-activity landscapes is essential in drug discovery. Similarly, it has been shown that the presence of activity cliffs in compound data sets can have a substantial impact not only on the design progress but also can influence the predictive ability of machine learning models. With the continued expansion of the chemical space and the currently available large and ultra-large libraries, it is imperative to implement efficient tools to analyze the activity landscape of compound data sets rapidly. The goal of this study is to show the applicability of the n-ary indices to quantify the structure-activity landscapes of large compound data sets using different types of structural representation rapidly and efficiently. We also discuss how a recently introduced medoid algorithm provides the foundation to finding optimum correlations between similarity measures and structure-activity rankings. The applicability of the n-ary indices and the medoid algorithm is shown by analyzing the activity landscape of 10 compound data sets with pharmaceutical relevance using three fingerprints of different designs, 16 extended similarity indices, and 11 coincidence thresholds. | Timothy Dunn; Edgar Lopez-Lopez; Taewon Kim; Jose Luis Medina Franco; Ramon Miranda-Quintana | Theoretical and Computational Chemistry; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-01-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63d0a1f21fe1425ae858c3a6/original/exploring-activity-landscapes-with-extended-similarity-is-tanimoto-enough.pdf |
60c74b80702a9b642418b445 | 10.26434/chemrxiv.12046125.v2 | Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags | <p></p><p><i>In situ</i>
visualization of proteins of interest at single cell level is attractive in
cell biology, molecular biology and biomedicine, which usually involves photon,
electron or X-ray based imaging methods. Herein, we report an optics-free
strategy that images a specific protein in single cells by time of
flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation
of fluorine-containing unnatural amino acids as a chemical tag into the protein
via genetic code expansion technique. The method was developed and validated by
imaging GFP in E. coli and human HeLa cancer cells, and then utilized to
visualize the distribution of chemotaxis protein CheA in E. coli cells and the
interaction between high mobility group box 1 protein and cisplatin damaged DNA
in HeLa cells. The present work highlights the power of ToF-SIMS imaging
combined with genetically encoded chemical tags for <i>in situ </i>visualization
of proteins of interest as well as the interactions between proteins and drugs
or drug damaged DNA in single cells.</p><p></p> | Feifei Jia; Jie Wang; Yanyan Zhang; Qun Luo; Luyu Qi; Yinzhu Hou; Jun Du; Yao Zhao; Fuyi Wang | Biochemical Analysis; Imaging; Mass Spectrometry | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74b80702a9b642418b445/original/optics-free-visualization-of-proteins-in-single-cells-by-time-of-flight-secondary-ion-mass-spectrometry-coupled-with-genetically-encoded-chemical-tags.pdf |
60c751e40f50dbb36c39786e | 10.26434/chemrxiv.13224734.v1 | Evaluating Landfill Diversion Strategies for Municipal Organic Waste (MOW) Management Using Environmental and Economic Factors | <p>We apply systems engineering principals and life cycle analysis (LCA) to municipal waste supply chains to elucidate sustainability incentives. Environmental impacts are quantified using LCA for waste management technologies available in the supply chain, and included as products. The supply chain is modeled as a coordinated market and resolved using mathematical optimization techniques. Incorporating impacts as products allows us to analyze the influence of tax policy on optimal waste management strategies.</p> | Philip Tominac; Horacio Aguirre-Villegas; Joseph Sanford; Rebecca A. Larson; Victor Zavala | Environmental Science | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c751e40f50dbb36c39786e/original/evaluating-landfill-diversion-strategies-for-municipal-organic-waste-mow-management-using-environmental-and-economic-factors.pdf |
66fdbba751558a15efe17f35 | 10.26434/chemrxiv-2024-vj0vk | An Improved P(V) Oligonucleotide Synthesis Platform | Three critical advances in simplifying the adoption of P(V)-based stereopure, phosphorothioate-containing oligonu-cleotide synthesis are reported. A more inexpensive phosphorus-sulfur incorporation reagent (Ψ-Br) is introduced, a robust linker system was developed, and a systematic study of common nucleobase protecting groups performed to significantly reduce the barrier to adoption of this technology. | Molhm Nassir; Luca Gherardi; Richard L. Redman; Yonghao Jin; Feng Yao; Yang Yang; Nicholas Raheja; Arjun Natarajan; David Butler; Kyle W. Knouse; Phil S. Baran | Biological and Medicinal Chemistry; Organic Chemistry; Biochemistry; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY 4.0 | CHEMRXIV | 2024-10-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66fdbba751558a15efe17f35/original/an-improved-p-v-oligonucleotide-synthesis-platform.pdf |
64453e31df78ec50154457b1 | 10.26434/chemrxiv-2023-r4x57 | Cation Coordination Polyhedra Lead to Multiple Lengthscale Organization in Aqueous Electrolytes | Although long recognized, understanding multiple lengthscale correlations in the X-ray and neutron pair distribution functions of aqueous electrolytes remains a persistent challenge. This work leverages polyoxoanions to support cation-centric coordination polyhedra in NaNO$_{3(aq)}$ and NaNO$_{2(aq)}$ with characteristic pair-wise correlations interpreted through classical molecular dynamics simulations and graph-theoretical analyses. We demonstrate that the water oxygen Ow $\cdots$ Ow correlations associated with Na$^+$-coordination polyhedra (and their oligomers) have two characteristics lengthscales. That between 3.5 - 5.5 \AA\ is associated with Ow coordinated to the same Na$^+$, while the second between 5.5 - 7.5 \AA\ is associated with Ow coordinating different Na$^+$ connected by bridging anions, corner-, edge-, or face-sharing. The ubiquitous contraction of the PDF between 5.5 - 7.5 \AA\ observed in many electrolytes derives from the loss of the many-body bulk Ow $\cdots$ Ow and growth of all combinations of Ow and On correlations that emerge due to the ion network of Na-coordination polyhedra. | Yihui Wei; Emily Nienhuis; Sebastian Mergelsberg; Trent Graham; Qing Guo; Gregory Schenter; Carolyn Pearce; Aurora Clark | Theoretical and Computational Chemistry; Physical Chemistry; Clusters; Self-Assembly; Solution Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64453e31df78ec50154457b1/original/cation-coordination-polyhedra-lead-to-multiple-lengthscale-organization-in-aqueous-electrolytes.pdf |
64b57fadb605c6803be37de9 | 10.26434/chemrxiv-2023-w4821 | Manifold Projection Image Segmentation for Nano-XANES Imaging | As spectral imaging techniques are becoming more prominent in science, advanced image segmentation algorithms are required to identify appropriate domains in these images. We present a version of image segmentation called manifold projection image segmentation (MPIS) that is generally applicable to a broad range of systems without the need for training because MPIS uses unsupervised machine learning with a few physically motivated hyperparameters. We apply MPIS to nano-XANES imaging, where X-ray Absorption Near Edge Structure (XANES) spectra are collected with nanometer spatial resolution. We show the superiority of manifold projection over linear transformations, such as the commonly used Principal Component Analysis (PCA). Moreover, MPIS maintains accuracy while reducing computation time and sensitivity to noise compared to the standard nano-XANES imaging analysis procedure. Finally, we demonstrate how multimodal information, such as X-ray Fluorescence (XRF) data and spatial location of pixels, can be incorporated into the MPIS framework. We propose that MPIS is adaptable for any spectral imaging technique, including Scanning Transmission X-ray Microscopy (STXM), where the length scale of domains is larger than the resolution of the experiment. | Samantha Tetef; Ajith Pattammattel; Yong Chu; Maria Chan; Gerald Seidler | Analytical Chemistry; Nanoscience; Spectroscopy (Anal. Chem.); High-throughput Screening; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64b57fadb605c6803be37de9/original/manifold-projection-image-segmentation-for-nano-xanes-imaging.pdf |
60c74576bb8c1a8ba33da6b9 | 10.26434/chemrxiv.10028444.v1 | Re-Evaluating the Mechanism of Action of α,β-Unsaturated Carbonyl DUB Inhibitors B-AP15 and VLX1570: A Paradigmatic Example of Unspecific Protein Crosslinking with Michael Acceptor Motif-Containing Drugs | <div>Deubiquitinating enzymes are a growing target class across multiple disease states, with several inhibitors now reported. b-AP15 and VLX1570 are two structurally related USP14/UCH-37 inhibitors with a shared α,β-unsaturated carbonyl substructure motif. Initially taken forward into a phase I/II clinical trial for refractory multiple myeloma, VLX1570 has since been put on full clinical hold due to dose limiting toxicity. Through a proteomic approach, here we demonstrate that these compounds target a diverse range of proteins, resulting in the formation of higher molecular weight complexes. Activity-based proteome profiling identified CIAPIN1 as a sub-micromolar covalent target of VLX1570, and further analysis demonstrated that high molecular weight complex formation leads to aggregation of CIAPIN1 in intact cells. Our results suggest that in addition to DUB inhibition, these compounds induce non-specific protein aggregation through cross-linking, providing a molecular explanation for general cellular toxicity.</div> | Jennifer Ward; Adán Pinto-Fernández; LoÏc Cornelissen; Sarah Bonham; Laura Diaz Saez; Olivier Riant; Kilian Huber; Benedikt M. Kessler; Olivier Feron; Edward W. Tate | Mass Spectrometry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2019-10-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74576bb8c1a8ba33da6b9/original/re-evaluating-the-mechanism-of-action-of-unsaturated-carbonyl-dub-inhibitors-b-ap15-and-vlx1570-a-paradigmatic-example-of-unspecific-protein-crosslinking-with-michael-acceptor-motif-containing-drugs.pdf |
674e0493f9980725cfcff644 | 10.26434/chemrxiv-2024-j214n | Sample preparation methods for elemental analysis in electronic cigarette aerosols: a critical review | In the last decade, e-cigarettes have been marketed as a less harmful alternative to classical tobacco smoking and are currently being used by millions of people. An e-cigarette consists of an e-liquid and a heating device, generating an aerosol that the user can inhale. Recently, several studies have shown that metals and metalloids (=elementals), including As, Cd, Cr, and Pb, known carcinogens, were present in these aerosols. To ensure the accuracy of dose-toxicity estimations, it is essential to have access to reliable and reproducible methods for estimating the dose in question. Although more standardization methodologies were introduced in the analysis of elementals from aerosols, a huge divergence in sample preparation can be found in the literature. This work aimed to provide an overview of the scientific literature. Therefore, a literature search was conducted in September 2024, that followed the PRISMA guidelines. A total of 51 articles were selected for analysis and large variability in the sample preparation, specifically variations in aerosol generation characteristics and collection techniques could be observed. Despite the widespread use of methods as filters and impingers, many studies failed to validate critical steps such as aerosol recovery, blank corrections, and the extent of matrix effects. Therefore, further standardization of methodologies is urgently needed to improve the reliability of metal quantification in e-cigarette aerosols, which could potentially enhance regulatory frameworks and facilitate the routine analysis of e-cigarette emissions. | Maarten Dill; Sophia Barhdadi; Celine Vanhee; Eric Deconinck | Analytical Chemistry; Analytical Chemistry - General | CC BY NC ND 4.0 | CHEMRXIV | 2024-12-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/674e0493f9980725cfcff644/original/sample-preparation-methods-for-elemental-analysis-in-electronic-cigarette-aerosols-a-critical-review.pdf |
60c74d66842e650576db3473 | 10.26434/chemrxiv.12317273.v2 | Autocatalysis in Chemical Networks: Unifications and Extensions | Autocatalysis is an essential property for theories of abiogenesis and chemical evolution. However, the different formalisms proposed so far seemingly address different forms of autocatalysis and it remains unclear whether all of them have been captured. Furthermore, the lack of unified framework thus far prevents a systematic study of autocatalysis. Here, we derive general stoichiometric conditions for catalysis and autocatalysis in chemical reaction networks from basic principles in chemistry. This allows for a classification of minimal autocatalytic motifs, which includes all known autocatalytic systems and motifs that had not been reported previously. We further examine conditions for kinetic viability of such networks, which depends on the autocatalytic motifs they contain. Finally, we show how this framework extends the range of conceivable autocatalytic systems, by applying our stoichiometric and kinetic analysis to autocatalysis emerging from coupled compartments. The unified approach to autocatalysis presented in this work lays a foundation towards the building of a systems-level theory of chemical evolution.<br /> | Alex Blokhuis; David Lacoste; Philippe Nghe | Heterogeneous Catalysis; Homogeneous Catalysis; Chemical Kinetics | CC BY NC ND 4.0 | CHEMRXIV | 2020-07-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74d66842e650576db3473/original/autocatalysis-in-chemical-networks-unifications-and-extensions.pdf |
65dadcb59138d23161f3a4f2 | 10.26434/chemrxiv-2024-mzb6x | Catalytic Ortho C-H Methylation and Trideuteromethylation of Ar-ylthianthrenium Salts via the Catellani Strategy | We reported a Pd/NBE cooperative catalyzed ortho C−H methylation and trideuteromethylation of arylthianthrenium salts, enabling the efficient synthesis of a wide variety of (trideutero)methylated arenes in moderate to good yields. The method demonstrates excel-lent tolerance towards functional groups, scalability, and potential extension to the late-stage functionalization of biorelevant mole-cules. In combined with C−H thianthrenation of arenes, this approach provides an effective method for the site-selective C−H (trideutero)methylation of arenes. Additionally, this reaction represents the first example of a Catellani reaction involving aryl sul-fonium salts. | Chen Chen; Xiao-Xu Zhang; Zi-Yi Wang; Chunjie Ni; Bolin Zhu | Organic Chemistry; Catalysis; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65dadcb59138d23161f3a4f2/original/catalytic-ortho-c-h-methylation-and-trideuteromethylation-of-ar-ylthianthrenium-salts-via-the-catellani-strategy.pdf |
67419448f9980725cf917676 | 10.26434/chemrxiv-2024-30gfv | Visible light-mediated synthesis of 1,3-benzothiazoles: A comprehensive review | Photoredox catalysis has emerged as a powerful tool in organic synthesis, revolutionizing how chemists approach challenging bond-forming reactions. The importance of 1,3-benzothiazoles lies in their diverse roles in medicinal chemistry, materials science, and industrial applications, due to their stability, bioactivity, and versatility as building blocks. This review represents the most comprehensive work to date on photochemical methods for synthesizing 1,3-benzothiazoles, covering developments in this field from 2009 to 2024. It is organized by the types of starting compounds and discusses synthetic strategies for the target compounds alongside proposed reaction mechanisms. Notably, many established light-driven methods are photocatalyst-free and typically conducted under visible light (CFL, white, green, or blue LED) at room temperature. By exploring a range of synthetic methods, this review not only deepens our understanding of benzothiazole synthesis but also inspires possibilities for future advancements. We hope this review will motivate chemists to pursue new, environmentally friendly methods for synthesizing these and related biologically significant sulfur heterocycles. | Vitalii Palchykov | Organic Chemistry; Catalysis; Photochemistry (Org.); Organocatalysis; Redox Catalysis | CC BY 4.0 | CHEMRXIV | 2024-11-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67419448f9980725cf917676/original/visible-light-mediated-synthesis-of-1-3-benzothiazoles-a-comprehensive-review.pdf |
61c59c9d9efae73b4f255c59 | 10.26434/chemrxiv-2021-p4g7z | Discovery of Innovative Polymers for Next-Generation Gas-Separation Membranes using Interpretable Machine Learning | Polymer membranes perform innumerable separations with far-reaching environmental
implications. Despite decades of research on membrane technologies, design of new membrane
materials remains a largely Edisonian process. To address this shortcoming, we demonstrate a
generalizable, accurate machine-learning (ML) implementation for the discovery of innovative
polymers with ideal separation performance. Specifically, multitask ML models are trained on
available experimental data to link polymer chemistry to gas permeabilities of He, H2, O2, N2, CO2,
and CH4. We interpret the ML models and extract chemical heuristics for membrane design,
through Shapley Additive exPlanations (SHAP) analysis. We then screen over nine million
hypothetical polymers through our models and identify thousands of candidates that lie well above
current performance upper bounds. Notably, we discover hundreds of never-before-seen
ultrapermeable polymer membranes with O2 and CO2 permeability greater than 104 and 105 Barrer,
respectively, orders of magnitude higher than currently available polymeric membranes. These
hypothetical polymers are capable of overcoming undesirable trade-off relationship between
permeability and selectivity, thus significantly expanding the currently limited library of polymer
membranes for highly efficient gas separations. High-fidelity molecular dynamics simulations
confirm the ML-predicted gas permeabilities of the promising candidates, which suggests that
many can be translated to reality. | Jason Yang; Lei Tao; Jinlong He; Jeffrey McCutcheon ; Ying Li | Theoretical and Computational Chemistry; Polymer Science; Computational Chemistry and Modeling; Machine Learning; Chemoinformatics - Computational Chemistry; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2021-12-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61c59c9d9efae73b4f255c59/original/discovery-of-innovative-polymers-for-next-generation-gas-separation-membranes-using-interpretable-machine-learning.pdf |
65d1f5289138d23161621bd5 | 10.26434/chemrxiv-2024-nrq2k | Artificial Metalloenzyme Catalyzed Enantioselective Carboamination of Alkenes | Relying on ubiquitous alkenes, carboamination reactions enable the difunctionalization of the double bond by the concurrent formation of a C–N and a C–C single bond. In the past years, several groups have reported on elegant strategies for the carboamination of alkenes relying on homogeneous catalysts or enzymes. Herein, we report on an artificial metalloenzyme for the enantioselective carboamination of dihydrofuran. Genetic optimization, combined with a Bayesian optimization of catalytic performance, afforded the disubstituted tetrahydrofuran product in up to 22 TON and 85% ee. X-ray analysis of the evolved artificial carboaminase shed light on critical amino acid residues that affect catalytic performance. | Kun Yu; Ryo Tachibana; Corentin Rumo; Nico Igareta; Thomas Ward | Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65d1f5289138d23161621bd5/original/artificial-metalloenzyme-catalyzed-enantioselective-carboamination-of-alkenes.pdf |
63d8d21089c04b6693c468fc | 10.26434/chemrxiv-2023-khcgt | Calixcorrole | We recently reported that DDQ-mediated oxidative coupling of pyrrole to a free-base meso-triarylcorrole in dichloromethane at room-temperature results in the near-instantaneous formation of pyrrole-appended isocorroles. Herein we report that the use of refluxing dichloromethane and longer reaction times results in the oxidative addition of a second molecule of pyrrole, affording a novel isoporphyrinoid macrocycle calixcorrole in up to 47% yield. | Simon Larsen; Bjørn Ciceron Lukas Perez; Abhik Ghosh | Organic Chemistry; Organic Synthesis and Reactions; Physical Organic Chemistry; Supramolecular Chemistry (Org.) | CC BY 4.0 | CHEMRXIV | 2023-01-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63d8d21089c04b6693c468fc/original/calixcorrole.pdf |
6167f300fb86197653f7eee2 | 10.26434/chemrxiv-2021-08vx4 | A SARS-CoV-2 aptasensor based on electrochemical impedance spectroscopy and low-cost gold electrode substrates. | SARS-CoV-2 diagnostic practices broadly involve either qPCR based nucleic amplification or lateral flow assays (LFAs). qPCR based techniques suffer from the disadvantage of requiring thermal cycling (difficult to implement for low-cost field use) leading to limitation on sample to answer time, the potential to amplify viral RNA sequences after a person is no longer infectious and being reagent intense. LFA performance is restricted by qualitative or semi-quantitative readouts, limits on sensitivity and poor reproducibility. Electrochemical biosensors, and particularly glucose test strips, present an appealing platform for development of biosensing solutions for SARS-CoV-2 as they can be multiplexed and implemented at very low cost at point of use with high sensitivity and quantitative digital readout. This work reports the successful raising of an Opti-mer sequence for the spike protein of SARS-CoV-2 and then development of an impedimetric biosensor which utilises thin film gold sensors on low-cost laminate substrates from home blood glucose monitoring. Clinically relevant detection levels for SARS-CoV-2 are achieved in a simple, label-free measurement format using sample incubation times of 15 minutes. The biosensor developed here is compatible with mass manufacture, is sensitive and low-cost CE marked readout instruments already exist. These findings pave the way to a low cost and mass manufacturable test with the potential to overcome the limitations associated with current technologies. | Perrine Lasserre; Banushan Balansethupathy; Vincent J. Vezza; Adrian Butterworth; Alexander MacDonald; Ewen O. Blair; Liam McAteer; Stuart Hannah; Andrew C. Ward; Paul A. Hoskisson; Alistair Longmuir; Steven J. Setford; Eoghan C. W. Farmer; Michael E. Murphy; Harriet Flynn; Damion K. Corrigan | Analytical Chemistry; Electrochemical Analysis | CC BY NC ND 4.0 | CHEMRXIV | 2021-10-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6167f300fb86197653f7eee2/original/a-sars-co-v-2-aptasensor-based-on-electrochemical-impedance-spectroscopy-and-low-cost-gold-electrode-substrates.pdf |
60c74df5bdbb89772da39aae | 10.26434/chemrxiv.12672113.v1 | Single-Step Synthesis and Interface Tuning of Core–shell Metal–organic Framework Nanoparticles | Control over the spatial distribution of components in metal–organic frameworks has potential to unlock improved performance and new behaviour in separations, sensing and catalysis. We report an unprecedented single-step synthesis of multi-component metal–organic framework (MOF) nanoparticles, which form with a core–shell structure whose internal interface can be systematically tuned. We use scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and a new composition gradient model to fit high-resolution X-ray diffraction data to show how core–shell composition and interface characteristics are intricately controlled by synthesis temperature and reaction composition. Particle formation is investigated by in situ X-ray diffraction, which reveals that the spatial distribution of components evolves with time and is determined by the interplay of phase stability, crystallisation kinetics and diffusion. This work opens up new possibilities for the control and characterisation of functionality, component distribution and interfaces in MOF-based materials. | Kieran Orr; Sean M. Collins; Emily Reynolds; Frank Nightingale; Hanna Boström; Simon J. Cassidy; Daniel M. Dawson; Sharon Ashbrook; Oxana Magdysyuk; Paul A. Midgley; Andrew Goodwin; Hamish Yeung | Core-Shell Materials; Hybrid Organic-Inorganic Materials | CC BY NC ND 4.0 | CHEMRXIV | 2020-07-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74df5bdbb89772da39aae/original/single-step-synthesis-and-interface-tuning-of-core-shell-metal-organic-framework-nanoparticles.pdf |
677c848981d2151a0224f134 | 10.26434/chemrxiv-2025-k6kt5 | Thermodynamics of Self Assembly and Supramolecular Transitions using Enhanced Sampling | Computational studies of self-assembly have the potential to provide rich insights into their underlying thermodynamics and identify optimal system conditions for applications, such as nanomaterial synthesis or drug delivery. However, both self-assembly and supramolecular transitions can be hindered by free energy barriers, rendering them rare events on molecular timescales and making it challenging to sample them. Here, we show that the use of enhanced sampling techniques, when combined with a judiciously chosen set of order parameters, offers an efficient and robust route for characterizing the thermodynamics of self-assembly and supramolecular transitions. Specifically, we show that transitions between states with different periodicities or symmetries can be reversibly sampled by biasing a relatively small number of Fourier components of the particle density. We illustrate our approach by computing the free energy required to cleave a liquid slab and estimating the corresponding liquid-vapor surface tension. We also characterize the free energetics of the transition between spherical and rod-shaped droplets. These results serve as a first step towards the development of a systematic computational framework for exploring transitions in diverse supramolecular systems, such as surfactants or block copolymers, and characterizing the thermodynamics of their self-assembly. | Zhitong Jiang; Zachariah Vicars; Suruchi Fialoke; Sumanth N. Jamadagni; Peter H. Koenig; Amish J. Patel | Theoretical and Computational Chemistry; Materials Science; Chemical Engineering and Industrial Chemistry; Nanostructured Materials - Materials; Surfactants; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2025-01-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/677c848981d2151a0224f134/original/thermodynamics-of-self-assembly-and-supramolecular-transitions-using-enhanced-sampling.pdf |
60c745f6842e65ff61db2702 | 10.26434/chemrxiv.10293221.v1 | Photochemical Doyle-Kirmse Reaction – a Metal-Free Route to Allenes | This report describes metal-free, blue light-induced [2,3]-sigmatropic rearrangement of sulfonium ylides generated from donor/acceptor diazoalkanes and propargyl sulfides. The reaction furnishes highly functionalized allenes from a broad range of starting materials in decent yields. Mechanistic experiments supported by the literature data suggest singlet carbenes as intermediates in this reaction. | katarzyna Orłowska; Katarzyna Rybicka-Jasińska; Piotr Krajewski; Dorota Gryko | Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Photochemistry (Org.) | CC BY NC ND 4.0 | CHEMRXIV | 2019-11-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c745f6842e65ff61db2702/original/photochemical-doyle-kirmse-reaction-a-metal-free-route-to-allenes.pdf |
666c8b6301103d79c53b1989 | 10.26434/chemrxiv-2024-wc062 | Neutron Vibrational Spectroscopic Study of the Acetonitrile:Acetylene (1:2) Cocrystal Relevant to Titan, Saturn’s Moon | Saturn’s moon Titan features a surface composed of various organic solids with pronounced compositional and structural diversity. On top of the icy core, the surface experiences temperature of ~93 K and pressure of ~1.45 atm. Under these conditions, most small organic molecules exist as solids and form Titanean minerals. Acetonitrile and acetylene are two of these molecules, which can form single-component molecular solids, but also a 1:2 binary cocrystal. Here we present a combined neutron vibrational spectroscopic study, neutron powder diffraction study, and theoretical modeling of the cocrystal and the corresponding single-phase solids. This combined study resulted in insightful spectra–structure–properties correlations for the cocrystal and the molecular solids. Furthermore, we observed quenching of the high-temperature form of acetonitrile in the presence of the cocrystal, which supports the possibility of the existence of metastable solids as minerals on Titan. The results presented in this study further the knowledge of the putative structure and composition of the surface of Titan, and, at the same time, contributes to better understanding of the fundamental thermodynamic properties of two of the smallest organic molecules in the Universe. | Morgan Kramer; Luke Daemen; Yongqiang Cheng; Rafael Balderas-Xicohtencatl; Anibal Ramirez Cuesta; Craig Brown ; Tomce Runcevski | Theoretical and Computational Chemistry; Physical Chemistry; Earth, Space, and Environmental Chemistry; Space Chemistry; Physical and Chemical Properties; Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/666c8b6301103d79c53b1989/original/neutron-vibrational-spectroscopic-study-of-the-acetonitrile-acetylene-1-2-cocrystal-relevant-to-titan-saturn-s-moon.pdf |
67aab820fa469535b9cd1c43 | 10.26434/chemrxiv-2025-g62qh | Enhancing Metal–Support Interactions of Ru Catalysts via Relaxation of Oxygen Vacancies for Hydrogen Production | The stability of Ru-based catalysts under harsh electrochemical conditions is a critical challenge limiting their practical application in energy conversion systems. In this study, Ru catalysts supported on ZrO2-x, CeO2-x, and ZrCeO2-x were synthesized via pyrolysis of metal-organic frameworks (MOFs) and systematically evaluated to elucidate the role of support interactions on catalytic performance and durability. Advanced characterization techniques, including HR-TEM, XRD, XPS, and EXAFS, revealed that Ru-ZrCeO2-x exhibited superior structural stability compared to Ru-ZrO2-x and Ru-CeO2-x, particularly under high-potential sweep (HPS) conditions. The incorporation of Ce into ZrO2-x was shown to stabilize oxygen vacancies and enhance the interaction between Ru catalyst and the support, thereby mitigating catalyst degradation. Density functional theory (DFT) calculations further confirmed that Ce doping decreases formation energy of the oxygen vacancy, providing a thermodynamically favorable environment for Ru stabilization. This work demonstrates the promise of ZrCeO2-x as a robust support material for Ru-based catalysts, advancing their potential for durable and efficient energy applications. | Mansu Kim; Jonghwan Park; Hyuk Choi; Sohui Kim; Injoon Jang; Hyun You Kim; Namgee Jung; Sung Jong Yoo; Joseph Hupp; Dongmok Whang | Materials Science; Catalysis; Energy; Electrocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2025-02-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67aab820fa469535b9cd1c43/original/enhancing-metal-support-interactions-of-ru-catalysts-via-relaxation-of-oxygen-vacancies-for-hydrogen-production.pdf |
60d04a88b912f841be5ac4fc | 10.26434/chemrxiv-2021-bqkwt | A Fluorogenic Labeling of Live Viruses | Viruses are an important class of pathogens that can cause serious infectious diseases. The ability to directly analyze viral particles in real time is essential to understand their pathological functions. In this work, we developed a strategy for fluorogenic labeling of live viruses by using an optimal tetrazolate-functionalized AIEgen (Aggregation-induced emission luminogen), named PBET. Due to its AIE activities, this dye fluoresces weakly when dissolved in aqueous solution, thus providing dark fluorescence background. The fluorescence turn-on labeling is achieved by binding of PBET molecules into the outmost viral proteins (e.g., structural Capsid protein VP1), which triggers protein-induced fluorescence enhancement (PIFE) of PBET. Probably due to this PIFE/AIE-based sensing strategy, these PBET-labeled viruses can retain infectivity to a large extent, which is a great advantage for biologically friendly labeling. This fluorogenic labeling may find uses in imaging studies to combat virus-associated infectious diseases, especially those associated with previously unknown wild-type viruses. | Bin Zheng; Xianhuang Li; Sheng Xie; Shuodong Wang; Weiming Lai; Zhibiao Zhou; Qing Liu; Yujiao Yang; Bei Hou; Weiwei Ni; Jinsong Han; Yong Liu; Zebing Zeng; Tao Wang; Ben Zhong Tang | Biological and Medicinal Chemistry; Cell and Molecular Biology | CC BY NC ND 4.0 | CHEMRXIV | 2021-06-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60d04a88b912f841be5ac4fc/original/a-fluorogenic-labeling-of-live-viruses.pdf |
673c9fef7be152b1d09f6dc0 | 10.26434/chemrxiv-2024-v4f5x | Energy Decomposition Analysis for excited states: An Extension based on TDDFT | To enhance the understanding of photochemical reactivity and its mechanisms, it is essential to analyze bonding interactions in excited-state reactions. Such insights can aid in optimizing these reactions. This paper presents an energy decomposition analysis method for excited states (exc-EDA), integrating the ground state EDA approach by Morokuma, Ziegler and Rauk with time-dependent density functional theory (TDDFT). The methodology focuses on calculating excitation energies, particularly for the intermediate states of the EDA. We introduce two variants: the first uses non-relaxed excitation coefficients (exc-u-EDA), where the excitation coefficients of the excited fragment are used directly; the second optimizes these coefficients for the intermediate states (exc-r-EDA). Exc-EDA can be applied with various density functionals, but the accuracy depends on the functional’s ability to describe the excited state properly. Smaller basis sets result in lower energy values due to fewer virtual orbitals, while larger basis sets produce consistent relative results but may involve different excited states in intermediate steps leading to artificial increase of energy terms in the EDA. The method’s convergence behavior resembles that of TDDFT, with a computational cost approximately three times that of the underlying TDDFT calculation. Application of exc-EDA to singlet fission in pentacene clusters demonstrates its practical value, offering quantitative insights into excited-state bonding and revealing clear, intuitive trends. | Florian Kreuter; Ralf Tonner-Zech | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC 4.0 | CHEMRXIV | 2024-11-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/673c9fef7be152b1d09f6dc0/original/energy-decomposition-analysis-for-excited-states-an-extension-based-on-tddft.pdf |
60c747ce469df40196f438e3 | 10.26434/chemrxiv.11799573.v1 | Rapidly Forming Early Intermediate Structures Dictate the Pathway of Capsid Assembly | There are about 10<sup>30</sup> possible intermediates on the assembly path from hepatitis B capsid protein dimers to the 120-dimer capsid. If every intermediate was tested, assembly would often get stuck in an entropic trap and essentially every capsid would follow a unique assembly path. Yet, capsids assemble rapidly with minimal trapped intermediates, a realization of the Levinthal paradox. To understand the fundamental mechanisms of capsid assembly it is critical to resolve the early stages of the reaction. We have used Time-Resolved Small Angle X-ray Scattering, which is sensitive to solute size and shape and has millisecond temporal resolution. Scattering curves were fit to a thermodynamically curated library of assembly intermediates, using the principle of maximum entropy. Maximum entropy also provides a physical rationale for the selection of species. We found that the capsid assembly pathway was exquisitely sensitive to initial assembly conditions. With the mildest conditions tested, the reaction appeared two-state from dimer to 120-dimer capsid with some dimers-of-dimers and trimers-of-dimers. In slightly more aggressive conditions, we observed transient accumulation of a decamer-of-dimers and appearance of 90-dimer capsids. In conditions where there is measurable kinetic trapping, we found that a highly diverse early intermediates accumulated within a fraction of a second and propagated into long-lived kinetically trapped states (>90-mer). In all cases, intermediates between 35 and 90 subunits did not accumulate. These results are consistent with the presence of low barrier paths that connect early and late intermediates and direct the ultimate assembly path to late intermediates where assembly can be paused. | Roi Asor; Christopher John Schlicksup; Zhongchao Zhao; Adam Zlotnick; Uri Raviv | Biophysical Chemistry; Chemical Kinetics; Self-Assembly; Structure; Thermodynamics (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c747ce469df40196f438e3/original/rapidly-forming-early-intermediate-structures-dictate-the-pathway-of-capsid-assembly.pdf |
63550407ee3186872f6eba60 | 10.26434/chemrxiv-2022-3smb7-v2 | Monkeypox Virus Aggressively Invades via GP120 Domains and PI3K/GTPase-like System of F13 Protein | Infection with the monkeypox virus (MPXV) causes a condition comparable to that of smallpox, albeit with fewer symptoms and severity. The typical magnitude and duration of monkeypox epidemics will increase as human protection from the smallpox vaccine wanes. In this study, the bioinformatics technique of domain search was utilized to investigate the biological function of the F13 protein of the E protein of the monkeypox virus. According to the research annotation results, the F13 protein has G120, EF-hand, Protein kinase(PI3K) and phosphatase(PPM), GB1/RHD3-type, GAP/GEF, PhoLip ATPase, and Dynamin GTPase domains. The PI3K domain regulates Dynamin GTPase activity in a unique manner. This shows that the monkeypox virus binds to cellular receptors in a manner similar to HIV and then completes the membrane fusion process by mechanisms PI3K and GTPase -like system. | wenzhong liu; hualan li | Biological and Medicinal Chemistry; Biochemistry; Bioinformatics and Computational Biology; Chemical Biology | CC BY 4.0 | CHEMRXIV | 2022-10-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63550407ee3186872f6eba60/original/monkeypox-virus-aggressively-invades-via-gp120-domains-and-pi3k-gt-pase-like-system-of-f13-protein.pdf |
61bb5417a53f1ba6a99dd456 | 10.26434/chemrxiv-2021-1fdps | Dicoordinate Au(I)–Ethylene Complexes as Hydroamination Catalysts | A series of gold(I)–ethylene complexes containing a family of bulky phosphine ligands has been prepared. The use of these sterically congested ligands is crucial to stabilize the gold(I)–ethylene bond and prevent decomposition, boosting up their catalytic performance in the highly underexplored hydroamination of ethylene. The precatalysts bearing the most sterically demanding phosphines showed excellent results reaching full conversion to the hydroaminated products under low ethylene pressure (1 bar). Kinetic analysis together with density functional theory (DFT) calculations revealed that the assistance of a second molecule of the nucleophile as a proton shuttle is preferred even when using an extremely congested cavity-shaped Au(I) complex. | Miquel Navarro; Macarena G. Alferez; Morgane de Sousa; Juan Miranda-Pizarro; Jesus Campos | Inorganic Chemistry; Catalysis; Organometallic Chemistry; Organometallic Compounds; Homogeneous Catalysis; Kinetics and Mechanism - Organometallic Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-12-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61bb5417a53f1ba6a99dd456/original/dicoordinate-au-i-ethylene-complexes-as-hydroamination-catalysts.pdf |
678389496dde43c9082faca1 | 10.26434/chemrxiv-2025-k6rc2 | Aromaticity and through-space electronic coupling in [2]catenanes comprising two intertwined, globally electron-delocalized octaphyrinoid rings | π-Conjugated molecules with nontrivial topologies, such as catenanes and knots, offer unique aromaticity and through-space electronic and magnetic interactions absent in traditional planar π-systems. However, their synthesis remains challenging, with prior examples showing only localized aromaticity in individual benzenoid rings. Here, we report the synthesis of a [2]catenane comprising two intertwined octaphyrinoid rings, each with 34 globally delocalized π-electrons, achieved using a passive metal-template strategy with 2,2’-dipyrromethene as the directing ligand. Experimental and theoretical studies reveal nearly orthogonal spatial arrangement of the rings in neutral catenane, stabilized by multiple [NH···N] and [S···N] close contacts. These rings exhibit global aromaticity with entangled magnetic shielding interactions. Upon four-electron oxidation, the system converts to a tetracation with two globally antiaromatic (32π) rings, where through-space bonding interactions minish the antiaromatic destabilization. Notably, counterions also affect (anti)aromaticity of the tetracations in single-crystal state, highlighting a dynamic interplay between molecular topology, electronic structure, and external interactions. | Yuguang Sui; Jiahang Hao; Shaofei Wu; Longbin Ren; Zebing Zeng; Jishan Wu; Yong Ni | Physical Chemistry; Organic Chemistry; Physical Organic Chemistry; Supramolecular Chemistry (Org.) | CC BY 4.0 | CHEMRXIV | 2025-01-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/678389496dde43c9082faca1/original/aromaticity-and-through-space-electronic-coupling-in-2-catenanes-comprising-two-intertwined-globally-electron-delocalized-octaphyrinoid-rings.pdf |
646cda21268ed316c944bc45 | 10.26434/chemrxiv-2023-zvh74 | Synthesis and Structural Characterization of Branched Bimetallic AuPd Nanoparticles with highly tunable optical response | Bimetallic nanostructures composed of gold (Au) and palladium (Pd) have garnered increased interest for their application in heterogeneous catalysis. This study reports a simple strategy for manufacturing Au@Pd bimetallic branched nanoparticles (NPs), which offer a tuneable optical response, using polyallylamine-stabilized branched AuNPs as template cores for Pd over-growth. The palladium content can be altered by manipulating the concentration of PdCl42- and ascorbic acid (AA) that are injected, which permit an overgrowth of Pd shell up to ca. 2 nm thick. The homogeneous distribution of Pd at the surfaces of Au NPs can be carried out regardless of their size or branching degree, which allows an adjustment of the plasmon response in the near-infrared (NIR) spectral range. As proof of concept, the nano-enzymatic activity of pure gold and gold-palladium NPs was compared, exploring their Peroxidase-like activity in the oxidation of TMB. The bimetallic AuPd nanoparticles demonstrate an increase in catalytic properties attributed to the presence of palladium at the surface of gold. | Silvia Nuti; Adrian Fernández-Lodeiro; Lidia Esther Chinchilla; Ana Belen Hungria; Jose Luis Capelo Martinez; Carlos Lodeiro; Javier Fernández-Lodeiro | Materials Science; Catalysis; Nanoscience; Nanofabrication; Nanostructured Materials - Nanoscience; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-05-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/646cda21268ed316c944bc45/original/synthesis-and-structural-characterization-of-branched-bimetallic-au-pd-nanoparticles-with-highly-tunable-optical-response.pdf |
65f3269666c1381729fdcdde | 10.26434/chemrxiv-2024-t8l8v | Polar Opposites Attract on Saturn’s Moon Titan | That polar and non-polar compounds do not spontaneously mix is a textbook rule of chemistry with few exceptions. Here we provide evidence for the intercalation of methane, ethane, and small hydrocarbons into the lattice structure of hydrogen cyanide (HCN), a highly polar molecule. Using cryogenic syntheses and Raman spectroscopy, we observe distinct shifts in vibrational modes in line with enhanced hydrogen bonding upon hydrocarbon insertion. Co-crystal structures composed of HCN and ethane that are both thermodynamically stable, and that closely match measured vibrational shifts are computationally predicted. Methane, ethane and HCN are major components of the atmosphere and surface of Saturn’s moon Titan, where they play key roles in shaping chemistry, weather, and landscape. Their intermixing may prove instrumental for explaining Titan’s chemical and geological evolution. | Fernando Izquierdo-Ruiz; Morgan Cable ; Robert Hodyss; Tuan Vu; Hilda Sandström; Alvaro Lobato; Martin Rahm | Theoretical and Computational Chemistry; Earth, Space, and Environmental Chemistry; Space Chemistry; Computational Chemistry and Modeling; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-03-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65f3269666c1381729fdcdde/original/polar-opposites-attract-on-saturn-s-moon-titan.pdf |
6686a89801103d79c5007a96 | 10.26434/chemrxiv-2024-v2qhb-v2 | Unveiling an Unexpected Branching Point in α-pinene Ozonolysis via Molecular Dynamics Guided Reaction Discovery | Secondary organic aerosols (SOAs) significantly impact Earth’s climate and human health. Although the oxidation of volatile organic compounds (VOCs) has been recognized as the major contributor to the atmospheric SOA budget, the mechanisms by which this process produces SOA-forming highly oxygenated organic molecules (HOMs) remain unclear. A major challenge is navigating the complex chemical landscape of these transformations, which traditional hypothesis-driven methods fail to thoroughly investigate. Here, we explored the oxidation of α-pinene, a critical atmospheric biogenic VOC, using a novel reaction discovery approach based on ab initio molecular dynamics and state-of-the-art enhanced sampling techniques. Our approach successfully identified all established reaction pathways of α-pinene ozonolysis, as well as discovered multiple novel species and pathways without relying on a priori chemical knowledge. In particular, we unveiled an unexpected branching point that leads to the rapid formation of alkoxy radicals, whose high and diverse reactivity help to explain hitherto unexplained oxidation pathways suggested by mass spectral peaks observed in α-pinene ozonolysis experiments. This branching point is likely prevalent across a variety of atmospheric VOCs and could be crucial in establishing the missing link to SOA-forming HOMs. | Huan Yang; Umberto Raucci; Siddharth Iyer; Galib Hasan; Thomas Golin Almeida; Shawon Barua; Anni Savolainen; Juha Kangasluoma; Matti Rissanen; Hanna Vehkamaki; Theo Kurten | Theoretical and Computational Chemistry; Physical Chemistry; Earth, Space, and Environmental Chemistry; Atmospheric Chemistry; Environmental Science; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6686a89801103d79c5007a96/original/unveiling-an-unexpected-branching-point-in-pinene-ozonolysis-via-molecular-dynamics-guided-reaction-discovery.pdf |
64a3d049ba3e99daef7c6739 | 10.26434/chemrxiv-2023-ng4n7-v2 | Low Apparent Activation Energy of Ammonia Synthesis over Ru Catalyst Supported by Hydrogen Storage Material | <p>Ruthenium
is an excellent catalyst for ammonia synthesis and recently shows quite high
activity when supported on materials with high electron-donating and
hydrogen-absorbing properties. The high activity is generally considered to originate
from the two effects: the electron-donating property of the support, which reduces
its apparent activation energy (<sup>app</sup>E<sub>a</sub>) to half of pure
Ru’s <sup>app</sup>E<sub>a</sub>, and the hydrogen-absorbing property, which increases
the active site by suppressing hydrogen poisoning, a drawback of ruthenium
catalysts. Here, we investigated the catalytic performance of ruthenium loaded
on TiMn<sub>2</sub>, a hydrogen storage material without electron-donating
property to ruthenium. Ruthenium on TiMn<sub>2</sub> showed the <sup>app</sup>E<sub>a</sub>
reduced by half despite the lack of electron-donating property. It is plausible
that the decreased <sup>app</sup>E<sub>a</sub> is due to the elimination of
hydrogen over Ru by TiMn<sub>2</sub>. The hydrogen storage capacity is also an essential
factor in discussing the <sup>app</sup>E<sub>a</sub>.</p> | Ryusei Morimoto; Takaya Ogawa; Kazuma Torii; Tetsu Seno; Hideyuki Okumura; Keiichi N. Ishihara | Catalysis; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64a3d049ba3e99daef7c6739/original/low-apparent-activation-energy-of-ammonia-synthesis-over-ru-catalyst-supported-by-hydrogen-storage-material.pdf |
64a3a2aa6e1c4c986bc5771d | 10.26434/chemrxiv-2023-t5bnk | Air-stable Copolymer Exhibiting Near-Infrared Long-Persistent Luminescence | Organic materials exhibiting long-lasting emission in the near infrared are expected to have applications in bio-imaging and other areas. Although room temperature phosphorescence and thermally activated delayed fluorescence display long-lived emission of approximately one minute, organic long-persistent luminescence (OLPL) systems with a similar emission mechanism to inorganic persistent emitters can emit for several hours at room temperature. In particular, OLPL with a hole-diffusion mechanism can function even in the presence of oxygen. However, ionic materials lack long-term stability in neutral organic host owing to aggregation and phase separation. In this study, we synthesised polymers with stable near-infrared persistent luminescence at room temperature via the copolymerisation of electron donors and acceptors. The copolymers exhibit long-persistent luminescence (LPL) at temperatures below the glass transition temperature and can be excited by approximately the entire range of visible light. LPL properties and spectra can be controlled by the dopant. | Zesen Lin; Maosheng Li; Ryota Kabe | Physical Chemistry; Photochemistry (Physical Chem.); Physical and Chemical Properties; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64a3a2aa6e1c4c986bc5771d/original/air-stable-copolymer-exhibiting-near-infrared-long-persistent-luminescence.pdf |
67378ef85a82cea2fa3d0457 | 10.26434/chemrxiv-2024-w7j26 | Solution and solid-state structures of dibenzylamino calix[4]arene with complexed solvent molecules | The solution and solid state structures of 1,3-dibenzylamino calix[4]arene were investigated via NMR and X-ray crystallography for MeCN, ethanol, hexane, THF, chloroform and toluene solvents. Analysis of the obtained structures show a symmetric flattening/pinching of the calixarene for solvents with a roughly cylindrical shape (MeCN, ethanol, hexane) and an asymmetrical flattening of the cone for more anisotropic, flat solvents, such as THF or toluene. Due to the deviation from planarity of the N2O2 fragment in the latter case, these solvents might be best suited for the preparation of octahedral or tetrahedral metal complexes, while the former would be more suitable for the preparation of square-planar complexes. | Matteo Cardoso; Jacques Beauchemin-Ratté; Frank Schaper | Organic Chemistry; Supramolecular Chemistry (Org.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-11-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67378ef85a82cea2fa3d0457/original/solution-and-solid-state-structures-of-dibenzylamino-calix-4-arene-with-complexed-solvent-molecules.pdf |
646fb56cbe16ad5c57e86d39 | 10.26434/chemrxiv-2023-gngqd | A modular flow platform enables selective and fast SuFEx ligation of small molecules, peptides, and proteins
| SuFEx click chemistry has established itself as a formidable tool to rapidly and effectively link chemical structures. Despite tremendous advancements in the field in recent years, the installment of the crucial -SO2F handle still requires the use of purposely designed, expensive, and non-atom economical reagents. However, the use of the most obvious reagent, SO2F2, has been twarthed by the difficulties associated with the manipulation and dosage of this toxic gas, as well as its apparent low reactivity with amino functionalities. Herein, we disclose a modular flow platform, which is able to generate on demand, and safely dose, gaseous SO2F2. Due to the use of flow technology, many lingering limitations of this transformation could be overcome, resulting in significantly reduced reaction times, high reactivity and exceptional reaction scope. The effectiveness of the process was demonstrated by the successful synthesis of a diverse set of fluorosulfates and sulfamoyl fluorides, including those derived from biorelevant compounds, peptides, and proteins. | Miguel Bernus; Daniele Mazzarella; Jelena Stanic; Ziran Zhai; Alejandro Yeste Vazquez; Omar Boutureira; Andrea Gargano; Tom Grossmann; Timothy Noel | Biological and Medicinal Chemistry; Organic Chemistry; Chemical Engineering and Industrial Chemistry; Organic Synthesis and Reactions; Process Chemistry; Pharmaceutical Industry | CC BY 4.0 | CHEMRXIV | 2023-05-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/646fb56cbe16ad5c57e86d39/original/a-modular-flow-platform-enables-selective-and-fast-su-f-ex-ligation-of-small-molecules-peptides-and-proteins.pdf |
61a683fc8029911417f88929 | 10.26434/chemrxiv-2021-7bx90 | Facile Polyolefin Plastics Hydrogenolysis Catalyzed by a Surface Electrophilic d0 Hydride | Polyolefins comprise a major fraction of single-use plastics and yet their catalytic
deconstruction/recycling has proven challenging due to their inert hydrocarbon connectivities.
Here an electrophilic earth-abundant single-site organozirconium catalyst chemisorbed on a highly
Brønsted acidic support and characterized by a broad array of experimental and theoretical
techniques, is shown to mediate the rapid hydrogenolytic cleavage of molecular and
macromolecular saturated hydrocarbons under mild conditions. For n-hexadecane, hydrogenolysis
to light hydrocarbons proceeds with an activity of 690 mol n-hexadecane · mol Zr-1 · h-1 at
150°C/2.5 atm H2 pressure. Under similar solventless conditions, polyethylene, polyethylene-co-
1-octene, isotactic polypropylene, and a post-consumer sandwich bag are rapidly hydrogenolyzed
to low molecular mass hydrocarbons via a turnover-limiting C-C scission pathway involving ßalkyl
transfer rather than more common σ-bond metathesis.
| Alexander H. Mason; Alessandro Motta; Anusheela Das; Qing Ma; Michael J. Bedzyk; Yosi Kratish; Tobin Marks | Catalysis; Organometallic Chemistry; Heterogeneous Catalysis; Bond Activation; Kinetics and Mechanism - Organometallic Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-12-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61a683fc8029911417f88929/original/facile-polyolefin-plastics-hydrogenolysis-catalyzed-by-a-surface-electrophilic-d0-hydride.pdf |
67c5b1e06dde43c9084c1006 | 10.26434/chemrxiv-2025-tvdzn | ‘Direct-to-biology’ drives optimisation of a cell-active covalent inhibitor of WRN helicase | We report a ‘direct-to-biology’ (D2B) approach for optimising covalent acrylamide binders of protein targets and apply this to the identification of a selective and cell-active inhibitor of Werner (WRN) helicase. Inhibition of WRN helicase activity exhibits a synthetic lethal relationship with cancers displaying high microsatellite instability (MSI-H) and is being pursued as a therapeutic strategy in the clinic. Using intact-protein liquid chromatography-mass spectrometry (LC-MS) screening, we identified acrylamide fragment binders of the WRN helicase domain and then used covalent D2B chemistry to optimise these initial hits. Our efforts ultimately afforded a potent covalent inhibitor of WRN-mediated DNA unwinding, which displays selective, concentration-dependent cellular engagement of WRN, and demonstrates synthetic lethality in an MSI-H setting. Furthermore, our inhibitor targets a distinct conformation of WRN helicase compared to the current clinical covalent inhibitor, presenting a complementary approach for covalent inhibition of WRN helicase. This work demonstrates how D2B chemistry platforms can be used to explore structure-activity relationships in a modular fashion, while reducing investment of human and material resources. | Sam M. Rowe; Alan Price; Dennis J. Murphy; Jiarong Lin; Eldridge N. Nartey; Apirat Chaikuad; Kristen Wong; Joshua E. Cottom; Nestor O. Concha; Robert A. Reid; Eleanor R. Dickinson; Melanie Jundt; Kerstin Kammerer; Michael Steidel; Toby Mathieson; Thilo Werner; Emma K. Grant; Charlotte K. Stanborough; Maxime Rouah; Justyna Wojno-Picon; Peter Pogány; Jonathan Pettinger; Daniel J. Norman; Harry Wilders; Francesco Rianjongdee; Gilberto Valdes-Garcia; Neysa Nevins; Raynold Shenje; Reema K. Thalji; Chun-wa Chung; H. Christian Eberl; Gitte Neubauer; David House; Yanhua Rao; Michael P. Martino; Jacob T. Bush | Biological and Medicinal Chemistry; Organic Chemistry; Biochemistry; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c5b1e06dde43c9084c1006/original/direct-to-biology-drives-optimisation-of-a-cell-active-covalent-inhibitor-of-wrn-helicase.pdf |
67c056de6dde43c908b45817 | 10.26434/chemrxiv-2025-j2jn3 | Concentration-Driven Reversible Morphological Transitions by the Self-Assembly of Crystalline-Coil Polyphosphazene-b-Polyestyrene (PP-b-PS) Block Copolymers | In this study, we demonstrate that varying the initial concentration of the poly-[bis(trifluoroethoxy)phosphazene]-b-poly(styrene) (PTFEP55-b-PS50) block copolymer enables the formation of diverse, well-defined nanomorphologies through self-assembly in tetrahydrofuran (THF). By adjusting the copolymer concentration, spherical micelles (0.1 mg/mL), bicontinuous micelles (0.33 mg/mL), toroidal micelles (2.0 mg/mL), cylindrical micelles (10 mg/mL), and vesicles (50 mg/mL) were successfully prepared. This simple methodology, using a single solvent and no additives, allowed for the investigation of morphological transformation mechanisms. Intermediate structures, such as "flower-like" morphologies (0.66 mg/mL), large compound micelles (LCMs. 1.0 mg/mL), and perforated micelles (1.5 mg/mL), were identified, revealing transitions between bicontinuous and toroidal morphologies. In situ studies captured the opening of toroidal structures into cylindrical micelles, while "octopod-like" structures were observed at intermediate concentrations between cylindrical and vesicular architectures. Wide-angle X-ray diffraction (WAXD) analysis showed that PTFEP blocks in the nanostructure cores are amorphous at low concentrations (<2 mg/mL) but exhibit increasing crystallinity at higher concentrations (>2 mg/mL), transitioning from toroidal to cylindrical and vesicular morphologies. This work highlights the ability to control the self-assembly of PTFEP-b-PS, generating a wide range of nanomorphologies by modulating PTFEP crystallinity through concentration adjustments. The unprecedented structural diversity of this system underscores its potential for designing advanced nanostructured materials. | Luis Quirós-Montes; David Presa-Soto; Raquel de la Campa; Gabino A. Carriedo; Alejandro Presa Soto | Inorganic Chemistry; Polymer Science; Nanoscience; Inorganic Polymers; Nanostructured Materials - Nanoscience; Polymers | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c056de6dde43c908b45817/original/concentration-driven-reversible-morphological-transitions-by-the-self-assembly-of-crystalline-coil-polyphosphazene-b-polyestyrene-pp-b-ps-block-copolymers.pdf |
66c8d576a4e53c48766421e8 | 10.26434/chemrxiv-2024-1zv1q | Investigating the Interaction between Excipients and Monoclonal Antibodies PGT121 and N49P9.6-FR-LS: A Comprehensive Analysis | N49P9.6-FR-LS and PGT121 are promising antibodies with significant therapeutic potential against HIV infection, but they are prone to precipitation at high concentrations. This study evaluates the influence of six excipients—L-arginine, L-alanine, sucrose, trehalose, methionine, and glutamate—on the biophysical stability of antibodies. We employed a comprehensive approach, combining computational mAb-excipient interaction analysis via the site-identification by ligand competitive saturation (SILCS) method with extensive experimental characterization. Our experimental matrix included viscosity measurements across temperature gradients, particle size distribution, zeta potential, pH value, and solution appearance, alongside a short-term stability study at 30°C and 65% relative humidity, with assessments at t0 (initial), t1 (14 days), and t2 (28 days). Results indicated that sucrose, arginine, alanine, and trehalose provided varying degrees of stabilization for both antibodies. Conversely, glutamate destabilized PGT121 but stabilized N49P9.6-FR-LS, while methionine had a negative effect on N49P9.6-FR-LS but a positive one on PGT121. SILCS-Biologics analysis suggested that stabilization by these excipients is linked to their ability to occupy regions involved in self-protein interactions. Debye–Hückel–Henry charge calculations further indicated that neutral excipients like sucrose and trehalose could alter mAb charges by affecting buffer binding, influencing aggregation propensity. These findings offer valuable insights for optimizing antibody formulations, ensuring enhanced stability and therapeutic efficacy for HIV treatment. | Li Xun; Asuka Orr; Mohammad Sajadi; Anthony DeVico; Daniel Deredge; Alexander MacKerell; Stephen Hoag | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Bioengineering and Biotechnology; Biophysics | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66c8d576a4e53c48766421e8/original/investigating-the-interaction-between-excipients-and-monoclonal-antibodies-pgt121-and-n49p9-6-fr-ls-a-comprehensive-analysis.pdf |
66c877a120ac769e5f91a836 | 10.26434/chemrxiv-2024-pwf3b | A dual role for the N-perfluorobutanesulfinamide auxiliary in an asymmetric decarboxylative Mannich reaction | Fluorine substitution is a powerful strategy in asymmetric synthesis to tune the properties of chiral catalysts, ligands, and auxiliaries. Herein, we demonstrate that the enhanced electrophilicity of N-perfluorobutanesulfinamide auxiliary-derived imines enables a highly selective decarboxylative Mannich reaction under mild conditions. The molecular sieves-mediated transformation tolerates a broad substrate scope and produces chiral beta-amino thioesters in high yield and stereoselectivity. Additionally, we demonstrate that the N-perfluoroalkyl sulfinyl group can function as a phase tag for fluorous purification, thus enabling the rapid and simple isolation of the chiral amine products by solid-phase extraction. The synthetic utility of this method is illustrated by the synthesis of the bioactive natural product negamycin, and the small molecules sitagliptin and ruspolinone. | Namitharan Kayambu; Torsten Cellnik; Assel Mukanova; Shinwon Kim; Alan R. Healy | Organic Chemistry; Catalysis; Natural Products; Organic Synthesis and Reactions; Stereochemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66c877a120ac769e5f91a836/original/a-dual-role-for-the-n-perfluorobutanesulfinamide-auxiliary-in-an-asymmetric-decarboxylative-mannich-reaction.pdf |
6509a91d60c37f4f760f6361 | 10.26434/chemrxiv-2023-9v8kt | Small Cobalt Nanoparticles Favor Reverse Water-Gas Shift Reaction over Methanation Under CO2 Hydrogenation Conditions | Cobalt-based catalysts are well-known to convert syngas into a variety of Fischer-Tropsch (FTS) products depending on the various reaction parameters, in particular particle size. In contrast, the reactivity of these particles has been much less investigated in the context of CO2 hydrogenation. In that context, surface organometallic chemistry (SOMC) was employed to synthesize highly dispersed cobalt nanoparticles (Co-NPs) with particle size ranging from 1.6 to 3.0 nm. These SOMC-derived Co-NPs display significantly different catalytic performances under CO2 hydrogenation conditions: while the smallest cobalt nanoparticles (1.6 nm) catalyze mainly the reverse water-gas shift reaction, the larger nanoparticles (2.1-3.0 nm) favor the expected methanation activity. Operando X-ray absorption spectroscopy shows that the smaller cobalt particles are fully oxidized under CO2 hydrogenation conditions, while the larger ones remain mostly metallic, paralleling the observed difference of catalytic performances. This fundamental shift of selectivity, away from methanation to reverse water-gas shift (rWGS) for the smaller nanoparticles is noteworthy and correlates with the formation of CoO under CO2 hydrogenation conditions. | Xiaoyu Zhou; Gregory A. Price; Glenn J. Sunley; Christophe Copéret | Inorganic Chemistry; Catalysis; Chemical Engineering and Industrial Chemistry; Spectroscopy (Inorg.); Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-09-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6509a91d60c37f4f760f6361/original/small-cobalt-nanoparticles-favor-reverse-water-gas-shift-reaction-over-methanation-under-co2-hydrogenation-conditions.pdf |
626967c7368ab65b3a8f3695 | 10.26434/chemrxiv-2022-qc76k | Synthesis and styrene copolymerization of halogen ring-trisubstituted 2-methoxyethyl phenylcyanoacrylates | Novel halogen ring-trisubstituted 2-methoxyethyl phenylcyanoacrylates, RPhCH=C(CN)CO2CH2CH2OCH3 (where R is 5-chloro-2,3-dimetoxy, 3-bromo-4,5-dimethoxy, 5-bromo-2,3-dimethoxy, 2-bromo-3-hydroxy-4-methoxy, 4-bromo-2,6-difluoro, 3-chloro-2,6-difluoro, 4-chloro-2,6-difluoro, 2-hydroxy-3,5-diiodo, 2,3,6-trichloro, 2,3,4-trifluoro, 2,4,6-trifluoro) were prepared and copolymerized with styrene. The acrylates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-trisubstituted benzaldehydes and 2-methoxyethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C NMR. All the acrylates were copolymerized with styrene in solution with radical initiation (ABCN) at 70C. The compositions of the copolymers were calculated from nitrogen analysis.
| Zipporah Y. Kaffey; Tyler J. McKenna; Angelina B. Moore; Abigail T. Noble; Simoni Patel; Ana S. Rivera; Joshua Sapinsley; Elena G. Sasso; Paige Sevald; Kay A.K. Smith; Sara M. Rocus; William S. Schjerven; Gregory B. Kharas | Organic Chemistry; Polymer Science; Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Organic Polymers | CC BY 4.0 | CHEMRXIV | 2022-04-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/626967c7368ab65b3a8f3695/original/synthesis-and-styrene-copolymerization-of-halogen-ring-trisubstituted-2-methoxyethyl-phenylcyanoacrylates.pdf |
67c0568afa469535b928363e | 10.26434/chemrxiv-2025-m27dr | Excited State Proton Transfer in 2-(Oxazol-2-yl)-3-hydroxychromone | The energy profiles and the dynamics of proton transfer (PT) in the excited states of the low-energy conformers of 2-(oxazol-2-yl)-3-hydroxychromone (OHC) are investigated. OHC has three low-energy conformers arising from the OH torsion and rotation about the CC bond bridging the chromone and oxazole rings. Two of them, OHC-A and B, have OH...O H-bonding within the chromone ring, while OHC-C has OH...N bonding between the chromone and oxazole rings. At the B3LYP/cc-pVDZ level, OHC-B and C are found to be similar in energy and OHC-A is slightly higher. Using TDA-B3LYP, the energy profiles computed on the lowest bright state indicate lower PT barriers for OHC-A and B compared to OHC-C. Fewest-switches surface hopping simulations initialized on both S1 and S2 for each conformer reveals different propensities for intra- and inter-ring PT. Through these simulations, we have attempted to understand the role of the excited states in the dynamics, propensities for PT, and fluorescence behaviour of the normal and PT forms of the conformers. | Dipangkali Sarma; Sai Ramesh | Theoretical and Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67c0568afa469535b928363e/original/excited-state-proton-transfer-in-2-oxazol-2-yl-3-hydroxychromone.pdf |
63d15cdf246f160b1eccd363 | 10.26434/chemrxiv-2023-f7n5n | Monodirectional photocycle drives proton translocation | Photoisomerization of retinal is pivotal to ion translocation across the bacterial membrane and has served as inspiration for the development of artificial molecular switches and machines. Light-driven synthetic systems in which a macrocyclic component transits along a nonsymmetric axle in a specific direction have been reported, however, unidirectional and repetitive translocation of small substrates, including ions, has not been achieved. Herein, we describe unique protonation-controlled isomerization behavior for hemi-indigo dyes bearing N-heterocycles, owing to intramolecular hydrogen bond formation. Light-induced isomerization from Z to E isomer is unlocked when protonated, while reverse E→Z photoisomerization occurs in the neutral state. As a consequence, associated protons are displaced in one direction with respect to the photoswitchable scaffold. We foresee that selective inhibition of photoswitching paths by substrate binding can be applied as general method toward directional transport and pumping of that substrate, which will prove critical in developing artificial systems in which concentration gradients can be effectively generated using (solar) light energy. | Nol Duindam; Michelle van Dongen; Maxime Siegler; Sander Wezenberg | Organic Chemistry | CC BY 4.0 | CHEMRXIV | 2023-01-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63d15cdf246f160b1eccd363/original/monodirectional-photocycle-drives-proton-translocation.pdf |
615eb2178b620d861147359a | 10.26434/chemrxiv-2021-v88c7 | Efficient Surrogates Construction of Chemical Processes: Case studies on Pressure Swing Adsorption and Gas-to-Liquids | We propose a workflow for reduction in the time required for data generation during generation of statistical digital twins. This methodology is particularly relevant for real-world engineering problems when data generation is expensive. A prerequisite for building surrogates is sufficient input/output data, whereas over-sampling can hardly improve the regression accuracy. The time for data generation can be reduced via (1) reduction of the average time spent on generating individual data points and (2) reduction in the total number of data points, by reducing the sampling rate with the improvement of surrogate quality. Examples of a dynamic process and a steady-state process from the field of carbon capture and utilization are used as two case studies: pressure swing adsorption (PSA) and Gas-to-Liquids (GTL). With the proposed methodology, the time for surrogate generation can be reduced by 88% for PSA and 60% for GTL, respectively. | Zhimian Hao; Chonghuan Zhang; Alexei Lapkin | Chemical Engineering and Industrial Chemistry; Reaction Engineering | CC BY 4.0 | CHEMRXIV | 2021-10-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/615eb2178b620d861147359a/original/efficient-surrogates-construction-of-chemical-processes-case-studies-on-pressure-swing-adsorption-and-gas-to-liquids.pdf |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.