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60c74becee301c465ec79f8b | 10.26434/chemrxiv.12401150.v1 | In Search of Molecular Ions for Optical Cycling: A Difficult Road | <div>
<div>
<div>
<p>Optical cycling, a continuous photon scattering off atoms or molecules, plays a
central role in the quantum information science. While optical cycling has been
experimentally achieved for many neutral species, few molecular ions have been investigated. We present a systematic theoretical search for diatomic molecular ions
suitable for optical cycling using equation-of-motion coupled-cluster methods. Inspired by the electronic structure patterns of laser-cooled neutral molecules, we establish the design principles for molecular ions and explore various possible cationic
molecular frameworks. The results show identifying a perfect molecular ion for optical cycling is challenging, yet possible. Among various possible diatomic molecules
we suggest several candidates, which require further attention from both theory and
experiment: YF+, SiO+, PN+, SiBr+, and BO+.
</p>
</div>
</div>
</div> | Maxim Ivanov; Thomas-C. Jagau; Guo-Zhu Zhu; Eric R. Hudson; Anna Krylov | Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74becee301c465ec79f8b/original/in-search-of-molecular-ions-for-optical-cycling-a-difficult-road.pdf |
6499576f2e632767b0cb9223 | 10.26434/chemrxiv-2023-gr02g | Modular and Practical 1,2-Aryl(alkenyl) Heteroatom Functionalization of Alkenes through Iron/Photoredox Dual Catalysis | Efficient methods for synthesizing 1,2-aryl(alkenyl) heteroatomic cores, encompassing heteroatoms such as nitrogen, oxygen, sulfur, and halogens, are of significant importance in medicinal chemistry and pharmaceutical research. In this study, we present a mild, versatile and practical photoredox/iron dual catalytic system that enables access to highly privileged 1,2-aryl(alkenyl) heteroatomic pharmacophores with exceptional efficiency and site selectivity. Our approach exhibits an extensive scope, allowing for the direct utilization of a wide range of commodity or commercially available (hetero)arenes as well as activated and unactivated alkenes with diverse functional groups, drug scaffolds, and natural product motifs as substrates. By merging iron catalysis with the photoredox cycle, a vast array of alkene 1,2-aryl(alkenyl) functionalization products that incorporate a neighboring azido, amino, halo, thiocyano and nitrooxy group were secured. The scalability and ability to rapid synthesize numerous bioactive small molecules from readily available starting materials highlight the utility of this protocol. | Weigang Zhang; Tao Liu; Hwee Ting Ang; Penghao Luo; Zhexuan Lei; Xiaohua Luo; Ming Joo Koh; Jie Wu | Organic Chemistry; Organic Synthesis and Reactions | CC BY 4.0 | CHEMRXIV | 2023-06-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6499576f2e632767b0cb9223/original/modular-and-practical-1-2-aryl-alkenyl-heteroatom-functionalization-of-alkenes-through-iron-photoredox-dual-catalysis.pdf |
60c73ede4c89196e80ad1e9a | 10.26434/chemrxiv.7176350.v1 | A Probabilistic Molecular Fingerprint for Big Data Settings | <p><b>Background</b>: Among the various molecular fingerprints available to describe
small organic molecules, ECFP4 (extended connectivity fingerprint, up to four
bonds) performs best in benchmarking drug analog recovery studies as it encodes
substructures with a high level of detail. Unfortunately, ECFP4 requires high
dimensional representations (≥1,024D) to perform well, resulting in ECFP4
nearest neighbor searches in very large databases such as GDB, PubChem or ZINC to
perform very slowly due to the curse of dimensionality. <a></a><a></a></p>
<p><b>Results</b>: Herein we report a new fingerprint, called MHFP6 (MinHash
fingerprint, up to six bonds), which encodes detailed substructures using the
extended connectivity principle of ECFP in a fundamentally different manner,
increasing the performance of exact nearest neighbor searches in benchmarking
studies and enabling the application of locality sensitive hashing (LSH)
approximate nearest neighbor search algorithms. To describe a molecule, MHFP6
extracts the SMILES of all circular substructures around each atom up to a
diameter of six bonds and applies the MinHash method to the resulting set.
MHFP6 outperforms ECFP4 in benchmarking analog recovery studies. Furthermore,
MHFP6 outperforms ECFP4 in approximate nearest neighbor searches by two orders
of magnitude in terms of speed, while decreasing the error rate. </p>
<p><b>Conclusion</b><a></a><a>: MHFP6 is a new molecular fingerprint, encoding circular
substructures, which outperforms ECFP4 for analog searches while allowing the
direct application of locality sensitive hashing algorithms. It should be well
suited for the analysis of large databases. The source code for MHFP6 is
available on GitHub (</a><a href="https://github.com/reymond-group/mhfp">https://github.com/reymond-group/mhfp</a>).<a></a></p> | Daniel Probst; Jean-Louis Reymond | Drug Discovery and Drug Delivery Systems; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2018-10-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73ede4c89196e80ad1e9a/original/a-probabilistic-molecular-fingerprint-for-big-data-settings.pdf |
60c743f0702a9b4c2918a6ea | 10.26434/chemrxiv.9698888.v1 | The Chemical Space from Which the Periodic System Arose | Mendeleev came across with his first attempt to a periodic system by classifying and ordering the known elements by 1869. Order and similarity were based on knowledge of chemical compounds, which gathered together constitute the chemical space by 1869. Despite its importance, very little is known about the size and diversity of this space and even less is known about its influence upon Mendeleev's periodic system. Here we show, by analysing 11.484 substances reported in the scientific literature up to 1869 and stored in Reaxys database, that 80\% of the space was accounted by 12 elements, oxygen and hydrogen being those with most compounds. We found that the space included more than 2,000 combinations of elements, of which 5\%, made of organogenic elements, gathered half of the substances of the space. By exploring the temporal report of compounds containing typical molecular fragments, we found that Meyer's and Mendeleev's available chemical space had a balance of organic, inorganic and organometallic compounds, which was, after 1830, drastically overpopulated by organic substances. The size and diversity of the space show that knowledge of organogenic elements sufficed to have a panoramic idea of the space. We determined similarities among the 60 elements known by 1869 taking into account the resemblance of their combinations and we found that Meyer's and Mendeleev's similarities for the chemical elements agree to a large extent with the similarities allowed by the chemical space. | Wilmer Leal; Eugenio J. Llanos; Peter F. Stadler; Juergen Jost; Guillermo Restrepo | Theory - Computational; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2019-08-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c743f0702a9b4c2918a6ea/original/the-chemical-space-from-which-the-periodic-system-arose.pdf |
60c73e14f96a00787d285e72 | 10.26434/chemrxiv.6376928.v1 | Revision of the crystal structure of “‘bis glycine’ squarate” [Tyagi et al., RSC Adv., 2016, 6, 24565] | The crystal structure of “‘bis glycine’ squarate”, recently published in RSC Advances [Tyagi et al., RSC Adv. 2016, 6, 24565], is revised. Re-refinement of the structure against<br />the original X-ray diffraction data after correct placement of the donor hydrogen atoms proves that the compound is the previously reported diglycinium squarate [Aniola et al.,<br />New J. Chem. 2014, 38, 3556]. | Rüdiger W. Seidel | Organic Compounds and Functional Groups | CC BY NC ND 4.0 | CHEMRXIV | 2018-05-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e14f96a00787d285e72/original/revision-of-the-crystal-structure-of-bis-glycine-squarate-tyagi-et-al-rsc-adv-2016-6-24565.pdf |
65d860dfe9ebbb4db907d927 | 10.26434/chemrxiv-2024-d0cff | Obtaining Robust Density Functional Tight Binding Parameters for Solids Across the Periodic Table | The Density Functional Tight Binding (DFTB) approach allows electronic structure based simulations at length and time scales far beyond what is possible with first-principles methods. This is achieved by using minimal basis-sets and empirical approximations. Unfortunately, the sparse availability of parameters across the periodic table is a significant barrier to the use of DFTB in many cases. We therefore propose a workflow that allows the robust and consistent parameterization of DFTB across the periodic table. Importantly, our approach requires no element-pairwise parameters so that the parameters can be used for all element combinations and are readily extendable. This is achieved by parameterizing all elements on a consistent set of artificial homoelemental crystals, spanning a wide range of coordination environments. The transferability of the resulting Periodic Table Baseline Parameters (\texttt{PTBP}) to multi-element systems and unknown structures is explored and the model is extensively benchmarked against previous specialized and general DFTB parameterizations. | Mengnan Cui; Karsten Reuter; Johannes T. Margraf | Theoretical and Computational Chemistry | CC BY NC 4.0 | CHEMRXIV | 2024-02-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65d860dfe9ebbb4db907d927/original/obtaining-robust-density-functional-tight-binding-parameters-for-solids-across-the-periodic-table.pdf |
60c743b4bdbb891771a386bd | 10.26434/chemrxiv.9479711.v1 | Self-assembly of an Organometallic Fe9O6 Cluster from Aerobic Oxidation of (tmeda)Fe(CH2tBu)2 | <div><div><div><p>Substoichiometric aerobic oxidation of the high-spin organometallic compound (tmeda)Fe(CH2tBu)2 (tmeda = N,N,N’,N’- tetramethylethylenediamine) in toluene or THF solution leads to the self-assembly of a magic-sized all-ferrous oxide cluster containing the Fe9O6 subunit and bearing organometallic and diamine ligands. Mössbauer studies of the cluster and the reference complex (tmeda)Fe(OCPh3)2 are consistent with the all-ferrous assignment, and magnetometry reveal considerable antiferromagnetic coupling between Fe atoms in the cluster and frustrated antiferromagnetic interactions between clusters in the solid state.</p></div></div></div> | Jonathan Kephart; Zachary Hecht; Brooke N. Livesay; Matthew P. Shores; V. Codrina Popescu; Navamoney Arulsamy; Elliott Hulley | Magnetism; Coordination Chemistry (Organomet.); Clusters | CC BY NC ND 4.0 | CHEMRXIV | 2019-08-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c743b4bdbb891771a386bd/original/self-assembly-of-an-organometallic-fe9o6-cluster-from-aerobic-oxidation-of-tmeda-fe-ch2t-bu-2.pdf |
60c758e69abda26e43f8e9b5 | 10.26434/chemrxiv.14612262.v1 | Bulky PNP Ligands Blocking Metal-Ligand Cooperation Allow for Isolation of Ru(0), and Lead to Catalytically Active Ru Complexes in Acceptorless Alcohol Dehydrogenation | We synthesized two 4Me-PNP
ligands which block metal-ligand cooperation (MLC) with the Ru center and
compared their Ru complex chemistry to their two traditional analogues used in acceptorless
alcohol dehydrogenation catalysis. The corresponding 4Me-PNP complexes, which
do not undergo dearomatization upon addition of base, allowed us to obtain rare,
albeit unstable, 16 electron mono CO Ru(0) complexes. Reactivity with CO and H<sub>2</sub>
allows for stabilization and extensive characterization of bis CO Ru(0) 18
electron and Ru(II) cis and trans dihydride species that were also shown to be capable
of C(sp<sup>2</sup>)-H activation. Reactivity and catalysis are contrasted to
non-methylated Ru(II) species, showing that an MLC pathway is not necessary,
with dramatic differences in outcomes during catalysis between <sup>i</sup>Pr
and <sup>t</sup>Bu PNP complexes within each of the 4Me and non-methylated
backbone PNP series being observed. Unusual intermediates are characterized in one
of the new and one of the traditional complexes, and a common catalysis
deactivation pathway was identified. | Shubham Deolka; Robert R. Fayzullin; Eugene Khaskin | Catalysis; Ligand Design; Ligands (Organomet.); Small Molecule Activation (Organomet.); Transition Metal Complexes (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-05-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c758e69abda26e43f8e9b5/original/bulky-pnp-ligands-blocking-metal-ligand-cooperation-allow-for-isolation-of-ru-0-and-lead-to-catalytically-active-ru-complexes-in-acceptorless-alcohol-dehydrogenation.pdf |
62d57471b464fa14b067bcae | 10.26434/chemrxiv-2022-46w7s | A batch photoreactor for small-scale laboratory research - a technical note | Photocatalysis for organic synthesis has experienced rapid progress over the last decades, which serves as an alternative to conventional synthetic routines. However, the photochemical reactor setup of many published works remains ambiguous due to missing standardized protocols. Therefore, a general design of batch photoreactor is required to circumvent the problem of difficult reproducibility and experimental inconsistencies. In this report which we have termed a technical note, a novel batch photoreactor with temperature feedback control and modulated light intensity was assembled from several low-cost, commercially available components, which will assist other researchers to reproduce this standardized reactor for use in their own research. | Jun Li; Patrick Hodapp; Bradley Paul Ladewig; Nicole Jung; Roland Dittmeyer | Organic Chemistry; Chemical Engineering and Industrial Chemistry; Photochemistry (Org.); Reaction Engineering | CC BY 4.0 | CHEMRXIV | 2022-07-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62d57471b464fa14b067bcae/original/a-batch-photoreactor-for-small-scale-laboratory-research-a-technical-note.pdf |
60fffc8ec0c36eb74fcd28e7 | 10.26434/chemrxiv-2021-cwrtm-v2 | The Preservation of English Oak in Marine Environments | This study compares the chemical integrity of English Oak (Quercus robur) samples with an age range of four centuries by analysing the lignin degradation. The samples were collected from four historic British vessels and thus represent samples of diverse ages which have nonetheless experienced similar non-arboreal environments. We conclude that the Mary Rose, the oldest vessel studied and the
recipient of the most intensive conservation efforts, has been well-preserved through treatment with PEG, and we present a baseline for assessing whether a ship hasbeen biologically degraded.
The work combines quantitative analytic chemistry techniques (e.g., THM-GC-MS) with the conservation of large historic artifacts. | Wren Montgomery; Eleanor Schofield; Jonathan S. Watson; Mark A. Sephton | Analytical Chemistry; Earth, Space, and Environmental Chemistry; Analytical Chemistry - General; Mass Spectrometry | CC BY 4.0 | CHEMRXIV | 2021-07-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60fffc8ec0c36eb74fcd28e7/original/the-preservation-of-english-oak-in-marine-environments.pdf |
66084f099138d23161c43fed | 10.26434/chemrxiv-2024-689vs-v4 | Spider Matrix: Towards Research Paper Evaluation and Innovation for Everyone | This study investigates the transformative effects of Artificial Intelligence (AI) on academic publishing, emphasizing the innovative Spider Matrix system. Designed for public use, this platform enables users to assess research papers and identify groundbreaking aspects. It addresses the challenges posed by the growing volume of publications and the imperative to uphold quality in scholarly communication. The paper highlights AI's pivotal role in enhancing the peer-review process. Through the Spider Matrix case study, the paper demonstrates AI's utility in appraising academic papers and patents across various dimensions, such as originality, robustness, and impact. This system goes beyond conventional metrics like citation counts, offering prompt, equitable evaluations grounded in the intrinsic quality of each work. Its adaptability to different academic fields and patent analysis underscores its versatility and efficacy in providing a more equitable and comprehensive framework for scholarly assessment. Additionally, the system is noted for its ability to generate innovative ideas from significant evaluation results. This paper emphasizes AI's potential to revolutionize academic guidance, publishing, and the generation of innovative ideas, aligning with the growing need for more meaningful and substantial research impact metrics. Ultimately, this leads to higher quality research outputs. | Yanheng XU; Shuqian Ye; Rulin Liu; Ling Shao; Xi Zhu | Theoretical and Computational Chemistry; Materials Science; Machine Learning | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66084f099138d23161c43fed/original/spider-matrix-towards-research-paper-evaluation-and-innovation-for-everyone.pdf |
64bfad1fb053dad33ada49d3 | 10.26434/chemrxiv-2023-6ml06 | Formoxyboranes as hydroborane surrogates for the catalytic re-duction of carbonyls through transfer hydroboration | A new class of Lewis base stabilized formoxyboranes demonstrates the feasibility of catalytic transfer hydroboration. In the presence of a ruthenium catalyst, they have shown broad applicability for reducing carbonyl compounds. Various borylated alcohols are obtained in high selectivity and yields up to 99 %, tolerating several functional groups. Computational studies enabled to propose a mechanism of this transformation, revealing the role of the ruthenium catalyst and the absence of hydroborane intermediates. | Gabriel Durin; R. Martin Romero; Timothé Godou; Clément Chauvier; Pierre Thuéry; Emmanuel Nicolas; Thibault Cantat | Organic Chemistry; Catalysis; Organometallic Chemistry; Homogeneous Catalysis; Main Group Chemistry (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64bfad1fb053dad33ada49d3/original/formoxyboranes-as-hydroborane-surrogates-for-the-catalytic-re-duction-of-carbonyls-through-transfer-hydroboration.pdf |
66d25d0af3f4b05290acfd75 | 10.26434/chemrxiv-2024-5mpgz | Temperature and hydroxyl radical abundance limit the photochemical degradation kinetics and photoproducts of fluridone in high-latitude aquatic systems | Temperature is often overlooked as an environmental driver of aquatic pollutant photodegradation kinetics; however, it may strongly impact contaminant persistence in polar climates characterized by low summertime temperatures and near-continuous sunlight. The photochemical degradation of fluridone (FLU), an herbicide applied worldwide to waterways for the eradication of invasive freshwater species, was investigated under simulated sub-arctic conditions typical of high-latitude surface waters. Temperature had a strong effect on the photochemical degradation of FLU, with half-lives for direct photochemical degradation ranging from approximately 40 h at 22 °C to 118 h at 9 °C under constant irradiation. Assessment of indirect processes involving reactive oxygen species indicated that FLU will primarily react with hydroxyl radicals (∙OH) and not singlet oxygen (1O2) produced by chromophoric dissolved organic matter (CDOM) in the environment. These results were corroborated by Fenton experiments, resulting in a calculated second order rate constant for the reaction with ∙OH of 8.37 x 109 M-1 s-1. Photoproduct identification revealed four main pathways for direct and indirect FLU photodegradation. Taken together, this work shows that direct photochemical degradation, which is dominant, is temperature dependent. Also, the interplay between light screening and ∙OH production of environmental CDOM, which is site dependent, will strongly influence FLU persistence. | Brian DiMento; Isabel Hillestad; Julie Sommer; Aidan Pavia; Niquelina Smith; Patrick Tomco; Zachary Redman | Earth, Space, and Environmental Chemistry; Hydrology and Water Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d25d0af3f4b05290acfd75/original/temperature-and-hydroxyl-radical-abundance-limit-the-photochemical-degradation-kinetics-and-photoproducts-of-fluridone-in-high-latitude-aquatic-systems.pdf |
60c74ee6842e654c1fdb3721 | 10.26434/chemrxiv.12816224.v1 | Distinct RNA N-Demethylation Pathways Catalyzed by Non-Heme Iron ALKBH5 and FTO Enzymes Enable Regulation of Formaldehyde Release Rates | <p>Abstract</p><p><br /></p><p>The AlkB family of non-heme-Fe(II)/2-oxoglutarate(2OG)-dependent oxygenases are essential regulators of RNA epigenetics by serving as erasers of one-carbon marks on RNA with release of formaldehyde (FA). Two major human AlkB family members, FTO and ALKBH5, both act as oxidative demethylases of N6 methyladenosine (m6A) but furnish different major products, N6 hydroxymethyladenosine (hm6A) and adenosine (A), respectively. Here we identify foundational mechanistic differences between FTO and ALKBH5 that promote these distinct biochemical outcomes. In contrast to FTO, which follows a traditional oxidative N-demethylation pathway to catalyze conversion of m6A to hm6A with subsequent slow release of A and FA, we find that ALKBH5 catalyzes a direct</p><p>m6A-to-A transformation with rapid FA release. We identify a catalytic R130/K132/Y139 triad within ALKBH5 that facilitates release of FA via an unprecedented covalent-based demethylation mechanism with direct detection of a covalent intermediate. Importantly, a K132Q mutant furnishes an ALKBH5 enzyme with an m6A demethylation profile that resembles that of FTO, establishing the importance of this residue in the proposed covalent mechanism. Finally, we show that ALKBH5 is an endogenous source of FA in the cell by activity-based sensing of FA fluxes perturbed via ALKBH5 knockdown. This work provides a fundamental biochemical rationale for non-redundant roles of these RNA demethylases beyond different substrate preferences and cellular localization, where m6A demethylation by ALKBH5 versus FTO results in release of FA, an endogenous one-carbon unit but potential genotoxin, at different rates in living systems.</p><p><br /></p><p><br /></p><p>Significance Statement</p><p><br /></p><p>Non-heme iron enzymes FTO and ALKBH5 play central roles in epigenetic RNA regulation by catalyzing the oxidation of N6-methyladenosine (m6A) to produce N6-hydroxymethyladenosine (hm6A) and adenosine (A), respectively. Here, we provide a mechanistic rationale for these distinct biochemical outcomes by identifying that ALKBH5 performs m6A demethylation via an unprecedented covalent-based mechanism with concomitant and rapid release of A and formaldehyde (FA), whereas FTO liberates hm6A to release A and FA over longer timescales. This work reveals foundational biochemical differences between these closely related but non-redundant epigenetic enzymes and identifies ALKBH5 as an endogenous source of rapid formaldehyde generation in cells.</p> | Joel D.W. Toh; Steven W. M. Crossley; Kevin Bruemmer; Eva J. Ge; Dan He; Diana Iovan; Christopher Chang | Biochemistry; Cell and Molecular Biology; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74ee6842e654c1fdb3721/original/distinct-rna-n-demethylation-pathways-catalyzed-by-non-heme-iron-alkbh5-and-fto-enzymes-enable-regulation-of-formaldehyde-release-rates.pdf |
60c751ff842e65e029db3c6c | 10.26434/chemrxiv.13221539.v1 | Improving Robustness of LCA Results Through Stakeholder Engagement: A Case Study of Emerging Oil Sands Technologies | Life cycle assessments can help to inform decision-making about greenhouse gas (GHG) emission reduction opportunities but are often not embraced by stakeholders associated with industries where study results are highly scrutinized and often contentious. This project was motivated by stakeholder interest in understanding open source life cycle models (the Oil Production Greenhouse Gas Emissions Estimator, OPGEE, and the Petroleum Refinery Life Cycle Inventory Model, PRELIM) and how accurately they can estimate emissions for existing oil sands projects and emerging technologies. We evaluate the robustness of these models and improve them using data from three existing oil sands projects (mining + upgrading, mining + dilution, and steam assisted gravity drainage, SAGD, + dilution). The models are then applied to estimate the GHG emissions reduction potential for two emerging in situ oil sands technologies. We find that, when boundaries are aligned, OPGEE can generate upstream GHG emissions estimates for the projects modeled within 1-4% of company reported GHG emissions data. Extending the boundary to include indirect (life cycle) emissions can lead to a doubling in upstream GHG emissions intensity. The two emerging technologies evaluated in the study can reduce upstream emissions by 14-19% compared to a SAGD project operating at the same reservoir, or 1.4-1.9% on a well-to-wheel basis. This work contributes a revised process of conducting LCAs that includes stakeholder input throughout and results in more robust and transparent estimations of emissions from deploying existing and emerging technologies.<br /> | Sylvia Sleep; Zainab Dadashi; yuanlei chen; Adam R. Brandt; Heather L. MacLean; Joule A. Bergerson | Environmental Science; Petrochemicals; Fuels - Energy Science | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c751ff842e65e029db3c6c/original/improving-robustness-of-lca-results-through-stakeholder-engagement-a-case-study-of-emerging-oil-sands-technologies.pdf |
6478ad05be16ad5c574a5b5b | 10.26434/chemrxiv-2023-wdbkx | An N-terminal selective thiazoline peptide macrocyclisation compatible with mRNA display and efficient SPPS | Discovery of new to nature ‘de novo’ macrocyclic peptides has been greatly facilitated by the integration of genetic recoding approaches with peptide display technologies. Perhaps most important among the changes that can made to a peptide to allow its use in a biological setting is macrocyclisation, which has beneficial impacts on target affinity, selectivity, stability, and cell permeability. However, introducing macrocyclisation into a linear sequence is unlikely to be successful unless the sequence is already primed to adpot an appropriate conformation. As a result it is important to include cyclisation already at the discovery stage, meaning there is a need for more diverse cyclisation options that can be deployed in the context of peptide display techniques such as mRNA display. In this work we show that meta-cyanopyridylalanine can be ribosomally incorporated into peptides, forming a macrocycle in a spontaneous and selective reaction with an N-terminal cysteine generated from bypassing the initiation codon in translation. This reactive amino acid can also be easily incorporated into peptides during standard Fmoc solid phase peptide synthesis, which can otherwise be a bottleneck in transfering from peptide discovery to peptide testing and application. We demonstrate the potential of this new method by discovery of macrocyclic peptides targeting influenza haemagglutinin, and molecular dynamics simulation indicates the mCNP cross-link stabilises a beta sheet structure in a representative of the most abundant cluster of active hits. Our new approach generates macrocycles with a more rigid cross-link and with better control of regiochemistry when additional cysteines are present, also allowing easy access to spontaneously forming bicyclic peptides, and so is a valuable addition to the mRNA display toolbox. | Minglong Liu; Richard Morewood; Ryoji Yoshisada; Mirte N. Pascha; Antonius J. P. Hopstaken; Eliza Tarcoveanu; David A. Poole III; Cornelis A. M. de Haan; Christoph Nitsche; Seino A. K. Jongkees | Biological and Medicinal Chemistry; Organic Chemistry; Bioorganic Chemistry; Organic Synthesis and Reactions; Drug Discovery and Drug Delivery Systems | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6478ad05be16ad5c574a5b5b/original/an-n-terminal-selective-thiazoline-peptide-macrocyclisation-compatible-with-m-rna-display-and-efficient-spps.pdf |
61f74f310716a8f5d341dceb | 10.26434/chemrxiv-2022-nb0fw | Room-Temperature Reversible Chemisorption of Carbon Monoxide on Nickel(0) Complexes | Chemisorption on organometallic-based adsorbents is crucial for the controlled separation and long-term storage of gaseous molecules. The formation of covalent bonds between the metal centers in the adsorbents and the targeted gases affects the desorption efficiency, especially when the oxidation state of the metal is low. Herein, we report a pressure-responsive nickel(0)-based system that is able to reversibly chemisorb carbon monoxide (CO) at room temperature. The use of N-heterocyclic carbene ligands with hemi-labile N-phosphine oxide substituents facilitates both the adsorption and desorption of CO on nickel(0) via ligand substitution. Ionic liquids were used as the reaction medium to enhance the desorption rate and establish a reusable system. These results showcase a way for the sustainable chemisorption of CO using a zero-valent transition-metal complex. | Yasuhiro Yamauchi; Yoichi Hoshimoto; Takahiro Kawakita; Takuya Kinoshita; Yuta Uetake; Hidehiro Sakurai; Sensuke Ogoshi | Organometallic Chemistry; Coordination Chemistry (Organomet.); Ligands (Organomet.); Transition Metal Complexes (Organomet.); Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-02-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61f74f310716a8f5d341dceb/original/room-temperature-reversible-chemisorption-of-carbon-monoxide-on-nickel-0-complexes.pdf |
60c740e6ee301c466cc78b4d | 10.26434/chemrxiv.7766786.v2 | Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties | <p>We have considered three two-dimensional (2D)
π-conjugated polymer networks (i.e., covalent organic frameworks, COFs)
materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their
electronic structures, investigated at the density functional theory
global-hybrid level, are indicative of valence and conduction bands that have
large widths, ranging between 1 and 2 eV. Using a molecular approach to derive
the electronic couplings between adjacent core units and the electron-vibration
couplings, the three π-conjugated 2D COFs are predicted to have ambipolar
charge-transport characteristics with electron and hole mobilities in the range
of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank
these 2D COFs among the highest-mobility organic semiconductors. In addition,
we have synthesized the zinc-porphyrin based 2D COF and carried out structural
characterization via powder X-ray diffraction and surface area analysis, which
demonstrates the feasability of these electroactive networks.</p> | Simil Thomas; Hong Li; Raghunath R. Dasari; Austin Evans; William Dichtel; Seth R. Marder; Veaceslav Coropceanu; Jean-Luc Bredas | Nanostructured Materials - Materials | CC BY NC ND 4.0 | CHEMRXIV | 2019-03-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c740e6ee301c466cc78b4d/original/design-and-synthesis-of-two-dimensional-covalent-organic-frameworks-with-four-arm-cores-prediction-of-remarkable-ambipolar-charge-transport-properties.pdf |
60c74bb6bb8c1ac6d43db283 | 10.26434/chemrxiv.12369479.v1 | Martini Coarse-Grained Models of Imidazolium-Based Ionic Liquids: From Nanostructural Organization to Liquid-Liquid Extraction | <div>
<div>
<div>
<p>Ionic liquids (IL) are remarkable green solvents, which find applications in many areas of nano- and
biotechnology including extraction and purification of value-added compounds or fine chemicals. These
liquid salts possess versatile solvation properties that can be tuned by modifications in the cation or anion
structure. So far, in contrast to the great success of theoretical and computational methodologies applied
to other fields, only a few IL models have been able to bring insights towards the rational design of such
solvents. In this work, we develop coarse-grained (CG) models for imidazolium-based ILs using a new
version of the Martini force field. The model is able to reproduce the main structural properties of pure ILs,
including spatial heterogeneity and global densities over a wide range of temperatures. More importantly,
given the high intermolecular compatibility of the Martini force field, this new IL CG model opens the
possibility of large-scale simulations of liquid-liquid extraction experiments. As examples, we show two
applications, namely the extraction of aromatic molecules from a petroleum oil model and the extraction of
omega-3 polyunsaturated fatty acids from a fish oil model. In semi-quantitative agreement with the
experiments, we show how the extraction capacity and selectivity of the IL could be affected by the cation
chain length or addition of co-solvents.
</p>
</div>
</div>
</div> | Luis Itza Vazquez-Salazar; Michele Selle; Alex H. de Vries; Siewert-Jan Marrink; Paulo C. T. Souza | Environmental Science; Separation Science; Nanostructured Materials - Nanoscience; Computational Chemistry and Modeling; Physical and Chemical Processes | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74bb6bb8c1ac6d43db283/original/martini-coarse-grained-models-of-imidazolium-based-ionic-liquids-from-nanostructural-organization-to-liquid-liquid-extraction.pdf |
66d5e65e12ff75c3a12f6975 | 10.26434/chemrxiv-2024-m37md | Roles of Chemical Species Transport and Transformation in the Biophysics of Human Pathophysiology | The human physiological system consists of several biological units carefully organized to engage in a bio-physicochemical interaction with complex fluids transporting nutritional and life-supporting species (oxygen and carbon dioxide) needed for the proper functioning of the body. The nutritional species are products of the chemical and mechanical transformation of macromolecular compounds such as polysaccharides, proteins, and lipids into simple molecules such as glucose, amino acids, and fatty acids. Life-supporting species access the body via ventilation and respiration. Alteration of these mechanisms, which include distortion in bioactive species transport and transformational processes, the influx of diet deficient of vitamins and nutrients needed for homeostasis, and pathogens considered foreign to the body, are precursors to most human pathophysiological conditions. This review focus on the roles of chemical species transport and transformation and their interactions with tissue structure and biomechanics in the causative mechanisms of an array of pathophysiological conditions considered as the world’s leading causes of death. Improved understanding of these roles will substantially assist in shaping and formulating a framework for multi-scale modelers and researchers interested in the quantitative description of chemical species transport and transformation in the biophysics of human physiology and pathophysiology. | Kazeem Olanrewaju; Ashlee N. Ford Versypt | Physical Chemistry; Biological and Medicinal Chemistry; Chemical Engineering and Industrial Chemistry; Bioengineering and Biotechnology; Bioinformatics and Computational Biology; Biophysics | CC BY 4.0 | CHEMRXIV | 2024-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d5e65e12ff75c3a12f6975/original/roles-of-chemical-species-transport-and-transformation-in-the-biophysics-of-human-pathophysiology.pdf |
65ae42589138d2316178c52b | 10.26434/chemrxiv-2024-h9skd | JEDI: A versatile code for strain analysis of molecular and periodic systems under deformation | Stretching or compression can induce significant energetic, geometric and spectroscopic changes in materials. To fully exploit these effects in the design of mechano- or piezochromic materials, self-healing polymers, and other mechanoresponsive devices, a detailed knowledge about the distribution of mechanical strain in the material is essential. Within the past decade, the Judgement of Energy DIstribution (JEDI) analysis has emerged as a useful tool for this purpose. Based on the harmonic approximation, the strain energy in each bond length, bond angle and dihedral angle of a deformed system is calculated using quantum chemical methods. This allows the identification of the force-bearing scaffold of the system, leading to an understanding of mechanochemical processes at the most fundamental level. Here we present a publicly available code that generalizes the JEDI analysis, which has previously only been available for isolated molecules. Now the code has been extended to two- and three-dimensional periodic systems, supramolecular clusters, and substructures of chemical systems under various types of deformation. Due to the implementation of JEDI into the Atomic Simulation Environment (ASE), the JEDI analysis can be interfaced with a plethora of program packages that allow the calculation of electronic energies for molecular systems and systems with periodic boundary conditions. The automated generation of a color-coded three-dimensional structure via the Visual Molecular Dynamics (VMD) program allows insightful visual analyses of the force-bearing scaffold of the strained system. | Henry Wang; Sanna Benter; Wilke Dononelli; Tim Neudecker | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65ae42589138d2316178c52b/original/jedi-a-versatile-code-for-strain-analysis-of-molecular-and-periodic-systems-under-deformation.pdf |
6331a804975e94101c899935 | 10.26434/chemrxiv-2022-btsrc-v2 | The Curious Case of Low-lying States in Non-linear Polyaromatic Hydrocarbons | The prediction of accurate singlet triplet (ST) gaps of polyaromatic hydrocarbons has been challenging due to the differential multireference character of the two states. The ST gaps of linear polyacenes have shown an exponential decay with system size due to the decreasing stability and increasing multireference nature of the singlet state. These low ST gaps can ideally be leveraged towards energy applications but is hindered by the decreasing stability of the system. While non-linear or kinked polyacenes are characterised by higher stability, multireference calculations on these systems are limited. In our work, we show that while the singlet states of kinked polyacenes are markedly less multireference, the triplet states are highly multireference in these systems and therefore, the correct trend of ST gap in the kinked polyacenes requires high-level multireference calculations. We show that unlike linear polyacenes, in the non-linear systems the ST gaps increase marginally with system size. The ST gaps also show absolutely no correlation with HOMO-LUMO gaps. These surprising trends are a combined effect of the non-linear connections (topology) and the geometrical factors. These results are in stark contrast to the observations in linear polyacenes. | Mandira DEY; Debashree Ghosh | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2022-09-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6331a804975e94101c899935/original/the-curious-case-of-low-lying-states-in-non-linear-polyaromatic-hydrocarbons.pdf |
655effa8cf8b3c3cd7ed5723 | 10.26434/chemrxiv-2023-hgw0g | A Solution to protodeborylation problem: weak base-promoted direct cross-coupling of naphthalene-1,8-diaminato-substituted arylboron compounds | Direct Suzuki–Miyaura cross-coupling (SMC) of naphthalene-1,8-diaminato (dan)-substituted organoboron reagents, previously requiring the use of a strong base for activation, has been successfully accomplished using a weak base in palladium/copper cocatalysis. This advancement allows for the efficient participation of various perfluoroaryl– and heteroaryl–B(dan) reagents, known for their outstanding resistance to protodeborylation. The formation of an aryl copper species through transmetalation between an aryl–B(dan) and a copper catalyst is pivotal for this smooth transformation. Furthermore, the inherent inertness of the B(dan) moiety arising from its diminished Lewis acidity allowed sequential cross-coupling, where other metallic moieties chemoselectively undergo the reaction, thus leading to the concise, protection-free synthesis of oligoarenes. | Kazuki Tomota; Jialun Li; Hideya Tanaka; Masaaki Nakamoto; Takumi Tsushima; Hiroto Yoshida | Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-11-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/655effa8cf8b3c3cd7ed5723/original/a-solution-to-protodeborylation-problem-weak-base-promoted-direct-cross-coupling-of-naphthalene-1-8-diaminato-substituted-arylboron-compounds.pdf |
67601c5afa469535b9d02384 | 10.26434/chemrxiv-2024-vd7w0 | Antibacterial metallacarborane-peptide hybrids target membrane potential in a non-lytic mode and show resistance to proteolysis | The urgent need for innovative antibiotics has driven the exploration of unconventional chemical frameworks to combat multidrug-resistant (MDR) bacteria. Metallacarboranes, particularly 3,3'-cobalt bis(dicarbollide) (COSAN) and its iodinated derivative I-COSAN, have demonstrated promise as antimicrobial agents because of their abiotic origins, stability, low toxicity, and unique physicochemical properties. In this study, we developed and characterized a novel class of metallacarborane-peptide hybrids with amphiphilic properties designed to mimic natural antimicrobial peptides (AMPs). These hybrids, consisting of cationic di- and tripeptides conjugated with COSAN or I-COSAN, exhibit broad-spectrum antibacterial and antibiofilm activities. By modulating the lipophilicity and charge of the hybrids, we optimized them for high antibacterial performance and biocompatibility. Mechanistic investigations revealed that the hybrids targeted the bacterial membrane potential, causing depolarization and ATP synthesis inhibition without inducing membrane lysis. These effects were accompanied by the overproduction of reactive oxygen species (ROS) and structural deformation of bacterial cells. The enhanced stability of these hybrids against proteolysis further underscores their therapeutic potential. This proof-of-concept study introduces metallacarborane‒peptide hybrids as a promising new class of antimicrobial agents with broad-spectrum activity, high stability, and a nonlytic mode of action. | Krzysztof Fink; Bożena Szermer-Olearnik; Anna Kędziora; Bartłomiej Dudek; Gabriela Bugla-Płoskońska; Waldemar Goldeman; Michalina Gos; Monika Cuprych-Belter; Mateusz Psurski; Paweł Migdał; Mariusz Uchman; Tomasz Goszczyński | Biological and Medicinal Chemistry; Inorganic Chemistry; Organometallic Chemistry | CC BY NC 4.0 | CHEMRXIV | 2024-12-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67601c5afa469535b9d02384/original/antibacterial-metallacarborane-peptide-hybrids-target-membrane-potential-in-a-non-lytic-mode-and-show-resistance-to-proteolysis.pdf |
60eea056a4e06b21767291a7 | 10.26434/chemrxiv-2021-pl2s1 | Discovery of a Potent and Highly Isoform-Selective Inhibitor of the Neglected Ribosomal Protein S6 Kinase Beta 2 (S6K2) | The ribosomal protein S6 kinase beta 2 (S6K2) is thought to play an important role in malignant cell proliferation but is understudied compared to its closely related isoform S6 kinase beta 1 (S6K1). To better understand the biological function of S6K2, chemical probes are needed but the high structural homology between S6K2 and S6K1 makes it challenging to selectively address S6K2 with small molecules. We were able to design the first potent and highly isoform-specific S6K2 inhibitor by merging a known S6K1-selective inhibitor with a covalent inhibitor known to engage a cysteine located in the hinge region in the fibroblast growth factor receptor kinase (FGFR) 4 via a nucleophilic aromatic substitution (SNAr) reaction. The title compound shows high selectivity over kinases with an equivalently positioned cysteine as well as in a larger kinase panel. Good stability towards glutathione indicated a non-promiscuous reactivity pattern. Thus, the title compound represents an important step towards a high-quality chemical probe to study S6K2-specific signalling. | Stefan Gerstenecker; Lisa Haarer; Martin Schröder; Mark Kudolo; Martin P. Schwalm; Valentin Wydra; Ricardo Serafim; Apirat Chaikuad; Stefan Knapp; Stefan Laufer; Matthias Gehringer | Biological and Medicinal Chemistry; Organic Chemistry; Organic Synthesis and Reactions; Chemical Biology; Drug Discovery and Drug Delivery Systems | CC BY NC ND 4.0 | CHEMRXIV | 2021-07-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60eea056a4e06b21767291a7/original/discovery-of-a-potent-and-highly-isoform-selective-inhibitor-of-the-neglected-ribosomal-protein-s6-kinase-beta-2-s6k2.pdf |
60c74308567dfe4efdec4023 | 10.26434/chemrxiv.8869412.v1 | Accelerated Computation of Free Energy Profile at ab Initio Quantum Mechanical/Molecular Mechanics Accuracy via a Semi-Empirical Reference Potential. II. Recalibrating Semi-Empirical Parameters with Force Matching | An efficient and accurate reference potential simulation protocol is proposed for producing ab initio quantum mechanical molecular mechanical (AI-QM/MM) quality free energy profiles for chemical<br />reactions in a solvent or macromolecular environment. This protocol involves three stages: (a) using force matching to recalibrate a semi-empirical quantum mechanical (SE-QM) Hamiltonian for the specific reaction under study; (b) employing the recalibrated SE-QM Hamiltonian (in combination with molecular mechanical force fields) as the reference potential to drive umbrella samplings along the reaction pathway; and (c) computing AI-QM/MM energy values for collected configurations from the sampling and performing weighted thermodynamic perturbation to acquire AI-QM/MM corrected reaction free energy profile. For three model reactions (identity SN2 reaction, Menshutkin reaction, and glycine proton transfer reaction) in aqueous solution and one enzyme reaction (Claisen arrangement in chorismate mutase), our simulations using recalibrated PM3 SE-QM Hamiltonians well reproduced AI-QM/MM free energy profiles (at the B3LYP/6-31G* level of theory) all within 1 kcal/mol with a 20 to 45 fold reduction in the computer time. | Xiaoliang Pan; Pengfei Li; Junming Ho; Jingzhi Pu; Ye Mei; Yihan Shao | Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2019-07-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74308567dfe4efdec4023/original/accelerated-computation-of-free-energy-profile-at-ab-initio-quantum-mechanical-molecular-mechanics-accuracy-via-a-semi-empirical-reference-potential-ii-recalibrating-semi-empirical-parameters-with-force-matching.pdf |
638607b64b1a5f5e63917f31 | 10.26434/chemrxiv-2022-1cgxg | Thermal Analysis of Arenediazonium Tetrafluoroborate Salts: Stability and Hazardous Evaluation | Arenediazonium salts represent an important class of aromatic organic compounds widely used as building blocks in academia and industry. Due to the high energy associated with the diazonium group, many of these salts are reported as thermally unstable and/or unsafe to work with. However, most of the tetrafluoroborate arenediazonium salts, are fairly stable to handle at room temperature both in solution and when dry. Nevertheless, some of these salts, especially those containing heteroatoms in the aromatic moiety, present difficulties in their synthesis, and some are indeed highly unstable. To bring some light to this controversial subject, the thermal stability and potential hazards of the 57 most common arenediazonium tetrafluoroborate salts used in our laboratory over the last two decades were evaluated under careful conditions. These results are expected to guide important decisions on the use of arenediazonium tetrafluoroborates in organic synthesis. | Edson de Souza; Tomaz Chorro; CARLOS CORREIA | Organic Chemistry; Organic Compounds and Functional Groups | CC BY NC 4.0 | CHEMRXIV | 2022-11-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/638607b64b1a5f5e63917f31/original/thermal-analysis-of-arenediazonium-tetrafluoroborate-salts-stability-and-hazardous-evaluation.pdf |
6766218a81d2151a02713563 | 10.26434/chemrxiv-2024-fq0qb-v2 | Capacity Decay in LiNiO2: An Atomistic Kinetic Picture | High-Ni layered oxides experience significant capacity decay over cycling, but the underlying mechanisms remain controversial. Using atomistic simulations, the electrochemical behavior of the fatigue phase is reproduced: a surface densified phase traps the last 25% of Li the end of charge, while discharge remains unimpeded. When the Li content falls to 25%, the remaining Li are locked into a superlattice, making the creation of vacancies the rate-limiting step for further delithiation. After cycling, the surface densified phase resembles Ni5O8 , with 25% Ni in the Li layer forming a similar superlattice. These Ni pin nearby Li, suppressing vacancy formation at the surface and kinetically trapping Li inside. Meanwhile, the Ni5O8 phase exhibits high diffusivity for Li interstitials in the superlattice, which explains the minimal resistance increase during discharge at the same Li content. Further densification leads to a surface phase that hinders both charge and discharge across the entire voltage range. | Penghao Xiao | Theoretical and Computational Chemistry; Energy; Computational Chemistry and Modeling; Energy Storage; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-12-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6766218a81d2151a02713563/original/capacity-decay-in-li-ni-o2-an-atomistic-kinetic-picture.pdf |
61106ea245805de759839c43 | 10.26434/chemrxiv-2021-dmdqr | α-Diimine Synthesis via Titanium-Mediated Multicomponent Diimination of Alkynes with C-Nitrosos | α-Diimines are commonly used as supporting ligands for a variety of transition metal-catalyzed processes, most notably in α-olefin polymerization. They are also precursors to valuable synthetic targets, such as chiral 1,2-diamines. Their synthesis is usually performed through acid-catalyzed condensation of amines with α-diketones. Despite the simplicity of this approach, accessing unsymmetrical α-diimines is challenging. Herein, we report the Ti-mediated intermolecular diimination of alkynes to afford a variety of symmetrical and unsymmetrical α-diimines through the reaction of diazatitanacyclohexadiene intermediates with C-nitrosos. These diazatitanacycles can be readily accessed in situ via the multicomponent coupling of Ti≡NR imidos with alkynes and nitriles. The formation of α-diimines is achieved through formal [4+2]-cycloaddition of the C-nitroso to the Ti and γ- carbon of the diazatitanacyclohexadiene followed by two subsequent cycloreversion steps to eliminate nitrile and afford the α- diimine and a Ti oxo. | Connor Frye; Dominic Egger; Errikos Kounalis; Adam Pearce; Yukun Cheng; Ian Tonks | Organic Chemistry; Inorganic Chemistry; Organometallic Chemistry; Organic Synthesis and Reactions; Kinetics and Mechanism - Organometallic Reactions; Transition Metal Complexes (Organomet.) | CC BY NC 4.0 | CHEMRXIV | 2021-08-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61106ea245805de759839c43/original/diimine-synthesis-via-titanium-mediated-multicomponent-diimination-of-alkynes-with-c-nitrosos.pdf |
62187649daa4fb695175f185 | 10.26434/chemrxiv-2022-0kdtn | Machine Learning Force Field Aided Cluster Expansion Approach to Configurationally Disordered Materials: Critical Assessment of Training Set Selection and Size Convergence | Cluster expansion (CE) is a powerful theoretical tool to study the configuration-dependent properties of substitutionally disordered systems. Typically, a CE model is built by fitting a few tens or hundreds of target quantities calculated by first-principles approaches. To validate the reliability of the model, a convergence test of cross-validation (CV) score to the training set size is commonly conducted to verify the sufficiency of training data. However, such test only confirms the convergence of the predictive capability of the CE model within the training set and it is unknown whether the convergence of the CV score would lead to robust thermodynamic simulation results such as order-disorder phase transition temperature $T_{\rm c}$. In this work, using carbon defective MoC$_{1-x}$ as a model system and aided by the machine-learning force field technique, a training data pool with about 13000 configurations has been efficiently obtained and used to generate different training sets of the same size randomly. By conducting parallel Monte Carlo simulations with the CE models trained with different randomly selected training set, the uncertainty in calculated $T_{\rm c}$ can be evaluated at different training set size. It is found that the training set size that is sufficient for the CV score to converge still leads to a significant uncertainty in the predicted $T_{\rm c}$, and that the latter can be considerably reduced by enlarging the training set to that of a few thousand configurations. This work highlights the importance of considering large training set for building the optimal CE model that can achieve robust statistical modeling results, and the facility provided by the machine-learning force field approach to efficiently produce adequate training data. | Jun-Zhong Xie; Xu-Yuan Zhou; Dong Luan ; Hong Jiang | Theoretical and Computational Chemistry; Theory - Computational; Machine Learning | CC BY NC ND 4.0 | CHEMRXIV | 2022-02-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62187649daa4fb695175f185/original/machine-learning-force-field-aided-cluster-expansion-approach-to-configurationally-disordered-materials-critical-assessment-of-training-set-selection-and-size-convergence.pdf |
60c75023f96a004be4287d73 | 10.26434/chemrxiv.12997574.v1 | Circumventing Scaling Relations in Oxygen Electrochemistry using Metal-Organic Frameworks | It has been well-established that unfavorable scaling relationships between *OOH, *OH, and *O are responsible for the high overpotentials associated with oxygen electrochemistry. A number of strategies have been proposed for breaking these linear constraints for traditional electrocatalysts (e.g. metals, alloys, metal-doped carbons); such approaches have not yet been validated experimentally for heterogenous catalysts. Development of a new class of catalysts capable of circumventing such scaling relations remains an ongoing challenge in the field. In this work, we use density functional theory (DFT) calculations to demonstrate that bimetallic porphyrin-based MOFs (PMOFs) are an ideal materials platform for rationally-designing the 3D active site environments for oxygen reduction reaction (ORR). Specifically, we show that the *OOH binding energy and the theoretical limiting potential can be optimized by appropriately tuning the transition metal active site, the oxophilic spectator, and the MOF topology. Our calculations predict theoretical limiting potentials as high as 1.07 V for Fe/Cr-PMOF-Al, which exceeds the Pt/C benchmark for 4e ORR. More broadly, by highlighting their unique characteristics, this works aims to establish bimetallic porphyrin-based MOFs as a viable materials platform for future experimental and theoretical ORR studies. | Tyler Sours; Anjli Patel; Jens Kehlet Nørskov; Samira Siahrostami; Ambarish Kulkarni | Electrocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75023f96a004be4287d73/original/circumventing-scaling-relations-in-oxygen-electrochemistry-using-metal-organic-frameworks.pdf |
615d8f44be107438db93b345 | 10.26434/chemrxiv-2021-llrtb | Divergent effects of laser irradiation on ensembles of nitrogen-vacancy centers in bulk and nano-diamonds: implications for biosensing | Ensembles of negatively charged nitrogen vacancy centers (NV-) in diamond have been proposed for sensing of magnetic fields and paramagnetic agents, and as a source of spin-order for the hyperpolarization of nuclei in magnetic resonance applications. To this end, strongly fluorescent nanodiamonds represent promising materials, with large surface areas and dense ensembles of NV-. However, surface effects tend to favor the less useful neutral form, the NV0 centers. Here, we study the fluorescence properties and optically detected magnetic resonance (ODMR) of NV- centers as a function of laser power in strongly fluorescent bulk diamond and in nanodiamonds obtained by nanomilling the native material. In bulk diamond, we find that increasing laser power increases ODMR contrast, consistent with a power-dependent increase in spin-polarization. Surprisingly, in nanodiamonds we observe a non-monotonic behavior, with a decrease in ODMR contrast at higher laser power that can be ascribed to more efficient NV-→NV0 photoconversion in nanodiamonds compared to bulk diamond, resulting in depletion of the NV- pool. We also studied this phenomenon in cell cultures following internalization of NDs in macrophages. Our findings show that surface effects in nanodiamonds substantially affect the NV properties and provide indications for the adjustment of experimental parameters. | Domingo Olivares Postigo; Federico Gorrini; Valeria Bitonto; Johannes Ackermann; Rakshyakar Giri; Anke Krueger; Angelo Bifone | Materials Science; Nanostructured Materials - Materials | CC BY 4.0 | CHEMRXIV | 2021-10-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/615d8f44be107438db93b345/original/divergent-effects-of-laser-irradiation-on-ensembles-of-nitrogen-vacancy-centers-in-bulk-and-nano-diamonds-implications-for-biosensing.pdf |
60c74f47337d6c6ee4e280f3 | 10.26434/chemrxiv.12834335.v2 | Interactive Molecular Dynamics in Virtual Reality (iMD-VR) Is an Effective Tool for Flexible Substrate and Inhibitor Docking to the SARS-CoV-2 Main Protease | The
main protease (Mpro) of the SARS-CoV-2 virus is one focus of drug development
efforts for antivirals to combat COVID-19. Here, we show that interactive molecular
dynamics in virtual reality (iMD-VR) is a useful and effective tool for
predicting structures of Mpro-ligand complexes. | Helen Deeks; Rebecca Walters; Jonathan Barnoud; David Glowacki; Adrian Mulholland | Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74f47337d6c6ee4e280f3/original/interactive-molecular-dynamics-in-virtual-reality-i-md-vr-is-an-effective-tool-for-flexible-substrate-and-inhibitor-docking-to-the-sars-co-v-2-main-protease.pdf |
66d6e378cec5d6c142fdb8ed | 10.26434/chemrxiv-2024-9w4t7 | An overview of physical and chemical long-range phenomena governed by Friedel oscillations: a~bridge between physics and chemistry | Friedel oscillations are quantum mechanical phenomena observed as oscillatory variations in electron density due to the presence of impurity or defect in a media containing electron gas. FOs profoundly influence surface properties, including the ordering of adsorbates and surface-mediated interactions crucial for catalytic activity. We delve into both experimental and theoretical aspects of FOs, organizing our discussion around the physicochemical systems of interest, the decay pattern, wavelength, and amplitude of FOs caused by different perturbations. Additionally, we present a systematic derivation of perturbed charge density distributions in one-, two-, and three-dimensional systems and establish a conceptual link between FOs, electron delocalization, and the mesomeric effect, using electron delocalization range function (EDR), offering insights into the reactivity of molecules featuring conjugated bonds. Finally, we propose an effective way to extend the analytical approach native to solid-state physics to describe charge oscillations in cumulenes and polyynes. | Alexandra Siklitskaya; Tomasz Bednarek; James Pogrebetsky; Adam Kubas | Theoretical and Computational Chemistry; Physical Chemistry; Catalysis; Physical and Chemical Processes; Quantum Mechanics; Surface | CC BY 4.0 | CHEMRXIV | 2024-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d6e378cec5d6c142fdb8ed/original/an-overview-of-physical-and-chemical-long-range-phenomena-governed-by-friedel-oscillations-a-bridge-between-physics-and-chemistry.pdf |
60c75805842e652127db47ce | 10.26434/chemrxiv.14489379.v1 | Enantioselective Addition of Pyrazoles to Dienes | We report the first enantioselective addition of pyrazoles to
1,3-dienes. Secondary and tertiary allylic pyrazoles can be generated
with excellent regioselectivity. Mechanistic studies support a pathway
distinct from previous hydroaminations: a Pd(0)-catalyzed ligand-to?ligand hydrogen transfer (LLHT). This hydroamination tolerates a
range of functional groups and provides a breakthrough in
hydrofunctionalization of dienes.
<br /> | Alexander Y. Jiu; Hannah Slocumb; Charles Yeung; Xiaohui Yang; Vy M. Dong | Catalysis; Main Group Chemistry (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75805842e652127db47ce/original/enantioselective-addition-of-pyrazoles-to-dienes.pdf |
67d0e32d6dde43c9087b5e0e | 10.26434/chemrxiv-2025-llnc4 | A novel photoaffinity probe for analysing the phosphatdylinositol 5-phosphate interactome | Phosphatidylinositol 5-phosphate (PI5P) plays a crucial role in cellular signalling, cell proliferation, the DNA damage repair response, and gene transcription. However, the underlying mechanism of PI5P function in these cellular pathways is poorly understood. This lack of understanding results, at least in part, from the dearth of available chemical tools to enable the investigation of PI5P interaction with target proteins in the corresponding biological systems. Here, we report the design and synthesis of a novel phosphatidylinositol 5-phosphate-based photoaffinity probe. We show that the probe binds, and photo-crosslinks, to the known PI5P-interacting proteins, hUHRF1 and hTAF3, and undergoes copper-catalyzed azide click chemistry with an azide-functionalized TAMRA dye, allowing visualization of these proteins. In addition, we demonstrate that this PI5P photoaffinity probe interacts with a range of proteins in the lysate of cultured human cell lines, through conjugated to a TAMRA-azide dye and subsequent fluorescent visualization. The data presented here validate the novel photoaffinity probe as an effective molecular tool to enable more detailed investigation of the PI5P interactome. | Glen Brodie; Ahmed Sayed; Sarah Kreuz; Wolfgang Fischle; Stuart Conway | Biological and Medicinal Chemistry; Chemical Biology | CC BY 4.0 | CHEMRXIV | 2025-03-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67d0e32d6dde43c9087b5e0e/original/a-novel-photoaffinity-probe-for-analysing-the-phosphatdylinositol-5-phosphate-interactome.pdf |
60c73f55bdbb896832a37f8e | 10.26434/chemrxiv.7291274.v1 | Dynamic Supramolecular Interaction in Cucurbit[7]uril Host-Guest Complex Enables Autonomous Single Molecule Blinking and Super-Resolution Imaging in Cells and Tissues | Synthetic supramolecular host-guest complexes are inherently dynamic as they employ weak and reversible noncovalent interactions for their recognition process. This dynamic behavior allows host-guest chemistry to be employed for various state of the art applications. Herein, we demonstrate the use of the dynamic supramolecular interaction to enable nanoscopic imaging inside cells and tissues. This imaging method exploits repetitive and transient binding of fluorescently labeled hexamethylenediamine (HMD) guest molecule to complementary cucurbit[7]uril (CB[7]) host to obtain stochastic switching between fluorescence ON- and OFF-states. Through connecting CB[7] hosts to targeting ligands (e.g., antibodies and small molecules), we show that this autonomous blinking enables two-dimensional (2D) and 3D super-resolution imaging of proteins in fixed cells and tissues. Finally, we exploited the capability of host-guest molecules to maintain their interaction specificity in the complexity of the live intracellular environment to obtain super-resolution actin imaging in living HeLa cell. | Ranjan Sasmal; Nilanjana Das Saha; Florian Schueder; Divyesh Joshi; Vasu Sheeba; Ralf Jungmann; Sarit Agasti | Supramolecular Chemistry (Org.); Imaging | CC BY NC ND 4.0 | CHEMRXIV | 2018-11-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73f55bdbb896832a37f8e/original/dynamic-supramolecular-interaction-in-cucurbit-7-uril-host-guest-complex-enables-autonomous-single-molecule-blinking-and-super-resolution-imaging-in-cells-and-tissues.pdf |
622b1917968f529929b6f95c | 10.26434/chemrxiv-2022-cpfwx | Water Structure at the Hydrophobic Droplet Surface Revealed by Vibrational Sum Frequency Scattering using Isotopic Dilution | Water structure at the hydrophobic/water interface is key towards understanding hydrophobicity at the molecular level. Herein, we characterize the hydrogen bonding network of interfacial water next to sub-micron sized hydrophobic droplets dispersed in water using isotopic dilution vibrational sum frequency scattering (SFS) spectroscopy. The relative intensity of different modes, the frequency shift of the uncoupled O-D spectrum and a low frequency shoulder (2395 cm-1) reveal that water forms an overall stronger hydrogen bonding network next to hydrophobic droplets compared to bulk water and the air/water interface. Roughly half of the spectral width of the oil droplet SFS spectrum is determined by inter- and intramolecular coupling of water molecules. Isotopic dilution also revealed a broad distribution (~2640 – 2750 cm-1) of non-hydrogen bonded O-D modes that were red-shifted and broadened compared to similar species observed previously at the air/water interface. This band confirms the presence of charge transfer between water and oil. | Saranya Pullanchery; Sergey Kulik; Sylvie Roke | Physical Chemistry; Interfaces; Spectroscopy (Physical Chem.); Surface | CC BY NC ND 4.0 | CHEMRXIV | 2022-03-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/622b1917968f529929b6f95c/original/water-structure-at-the-hydrophobic-droplet-surface-revealed-by-vibrational-sum-frequency-scattering-using-isotopic-dilution.pdf |
64361823a41dec1a56e75135 | 10.26434/chemrxiv-2023-dngg4 | Mole-BERT: Rethinking Pre-training Graph Neural Networks for Molecules | Recent years have witnessed the prosperity of pre-training graph neural networks (GNNs) for molecules. Typically, atom types as node attributes are randomly masked and GNNs are then trained to predict masked types as in AttrMask \citep{hu2020strategies}, following the Masked Language Modeling (MLM) task of BERT~\citep{devlin2019bert}. However, unlike MLM where the vocabulary is large, the AttrMask pre-training does not learn informative molecular representations due to small and unbalanced atom `vocabulary'. To amend this problem, we propose a variant of VQ-VAE~\citep{van2017neural} as a context-aware tokenizer to encode atom attributes into chemically meaningful discrete codes. This can enlarge the atom vocabulary size and mitigate the quantitative divergence between dominant (e.g., carbons) and rare atoms (e.g., phosphorus). With the enlarged atom `vocabulary', we propose a novel node-level pre-training task, dubbed Masked Atoms Modeling (MAM), to mask some discrete codes randomly and then pre-train GNNs to predict them. MAM also mitigates another issue of AttrMask, namely the negative transfer. It can be easily combined with various pre-training tasks to improve their performance. Furthermore, we propose triplet masked contrastive learning (TMCL) for graph-level pre-training to model the heterogeneous semantic similarity between molecules for effective molecule retrieval. MAM and TMCL constitute a novel pre-training framework, Mole-BERT, which can match or outperform state-of-the-art methods in a fully data-driven manner. We release the code at \textcolor{magenta}{\url{https://github.com/junxia97/Mole-BERT}}. | Jun Xia; Chengshuai Zhao; Bozhen Hu; Zhangyang Gao; Cheng Tan; Yue Liu; Siyuan Li; Stan Z. Li | Theoretical and Computational Chemistry; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64361823a41dec1a56e75135/original/mole-bert-rethinking-pre-training-graph-neural-networks-for-molecules.pdf |
657591f45bc9fcb5c97e4517 | 10.26434/chemrxiv-2023-vw3zz | Dithienylethene-based photoswitchable phosphines for light-controlled palladium-catalyzed Stille coupling reaction | Homogeneous transition metal catalysis is a constantly developing field of the chemical sciences. A growing interest in this area is photoswitchable catalysis, which pursues in-situ modulation of catalyst activity through non-invasive light irradiation. Phosphorus ligands are excellent targets to accomplish this goal by introducing photoswitchable moieties; however, only a limited number of examples has been reported so far. In this work we have developed a series of palladium complexes capable of catalyzing the Stille coupling reaction that contain photoisomerizable phosphine ligands based on dithienylethene switches. Incorporation of electron-withdrawing substituents into these dithienylethene moieties allows to vary the electron density on the phosphorus atom of the ligands upon light irradiation, which in turn leads to a modulation of the catalytic properties of the formed complexes and their activity in a model Stille coupling reaction. These results are supported by theoretical computations, which show that the energy barriers for the rate-determining steps of the catalytic cycle decrease when the photoswitchable phosphine ligands are converted to their closed state. | Anastasiia Sherstiuk; Agustí Lledós; Peter Lönnecke; Jordi Hernando; Rosa María Sebastián; Evamarie Hey-Hawkins | Inorganic Chemistry; Catalysis; Organometallic Chemistry; Homogeneous Catalysis; Ligand Design | CC BY NC ND 4.0 | CHEMRXIV | 2023-12-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/657591f45bc9fcb5c97e4517/original/dithienylethene-based-photoswitchable-phosphines-for-light-controlled-palladium-catalyzed-stille-coupling-reaction.pdf |
61ddef96a16050c6879de1c5 | 10.26434/chemrxiv-2022-pdsf4 | Quantifying community-wide antimicrobials usage via wastewater-based epidemiology | Increasing usage of antimicrobials is a significant contributor to the emergence and dissemination of antimicrobial resistance. Wastewater-based epidemiology is a useful tool for evaluating public health, via the monitoring of chemical and biological markers in wastewater influent, such as antibiotics. Chemical analyses are used to determine sampled drug concentrations; measured daily flows then enable quantitation of analyte mass/day; and population estimates are utilised to calculate mass/day/1000inhabitants. These data allow for effective evaluations of drug presence and temporal trends, but do not fully represent the total quantity of drugs being consumed, i.e., human intake. Factors such as drug metabolism and physiochemical stability significantly decrease the quantity of parent drug that reaches wastewater treatment plants, leading to potential underestimations of community usage. A case study of 16 antimicrobials, and their metabolites was conducted in this study: including sulfonamides, trimethoprim, metronidazole, quinolones, nitrofurantoin, cyclines, and antiretrovirals. Correction factors (CFs) for human drug excretion, for various metabolite forms, were determined via a systematic literature review of pharmacokinetic research. Analyte stability was examined over a 24 h study. The estimation of community-wide drug intake was evaluated using the associated catchment prescription data. Overall, antimicrobials excreted in an unchanged form were often observed to over-estimate daily intake. This could be attributed to biotransformation, e.g., via glucuronide cleavage, or direct disposal of unused drugs. Acetyl-sulfonamides, trimethoprim, hydroxy-metronidazole, clarithromycin, ciprofloxacin, ofloxacin, tetracycline, and oxytetracycline generally performed well in the estimation of drug intake, relative to prescription records. The low prevalence of quinolone and trimethoprim metabolites, and the low stability of nitrofurantoin, limited the ability to evaluate these metabolites and their respective CFs. CFs established in the systematic literature review could not be validated for some metabolites in the case study due to lack of available prescription data (lamivudine, emtricitabine); an inability to quantify biomarkers (nitrofurantoin, doxycycline); being excreted at too low levels (hydroxy-trimethoprim, ofloxacin-N-oxide, desethylene-ciprofloxacin); or insufficient pharmacokinetic literature sources (the nitrofurantoin metabolite, NPAHD). Further work is currently underway to apply established CFs in other catchment with higher prevalence of antimicrobials usage. | Elizabeth Holton; Natalie Sims; Kishore Jagadeesan; Richard Standerwick; Barbara Kasprzyk-Hordern | Biological and Medicinal Chemistry; Analytical Chemistry; Earth, Space, and Environmental Chemistry; Hydrology and Water Chemistry; Environmental Analysis; Mass Spectrometry | CC BY NC 4.0 | CHEMRXIV | 2022-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61ddef96a16050c6879de1c5/original/quantifying-community-wide-antimicrobials-usage-via-wastewater-based-epidemiology.pdf |
64de822801042bc1cc38ecad | 10.26434/chemrxiv-2023-7cg7h-v2 | Sulfurous Zeosils for Dehydra-Decyclization of Tetrahydrofuran to Renewable Butadiene
| Renewable 1,3-butadiene (1,3-BD, C4H6) was synthesized from the tandem decyclization and dehydration of biomass-derived tetrahydrofuran (THF) on weak Brønsted acid zeolite catalysts. 1,3-BD is a highly solicited monomer for the synthesis of rubbers and elastomers. Selective conversion of THF to 1,3-BD was recently measured on phosphorus-modified siliceous zeolites (P-zeosils) at both high and low space velocities, albeit with low per-site catalytic activity. In this work, we combined kinetic analyses and QM/MM calculations to evaluate the interaction of THF with the various Brønsted acid sites (BAS) of Boron (B)-, Phosphorus (P)-, and Sulfur (S)-containing silicalite-1 catalysts toward a dehydra-decyclization pathway to form 1.3-BD. Detailed kinetic measurements revealed that all three catalysts exhibited high selectivity to 1,3-BD ca. 64-96% in the order of S-MFI > P-MFI > B-MFI at a given temperature (360 C). Notably, the S-MFI maintained a selectivity > 90% for evaluated all process conditions. The computational results suggested that the nature of the Brønsted acid sites and the adsorption energetics (relative THF-acid site interaction energies) are distinct in each catalyst. Additionally, the protonation of THF can be improved with the addition of a water molecule acting as a proton shuttle, particularly in S-MFI. Overall, S-containing zeosils exhibited the ability to control reaction pathways and product distribution in dehydra-decyclization chemistry optimization within microporous zeolites, providing another alternative weak-acid catalytic material. | Raisa Carmen Andeme Ela; Jorge Barroso; Gaurav Kumar; Kaivalya Gawande; Manish Shetty; Xinyu Li; Wei Fan; Bess Vlaisavljevich; Paul Dauenhauer | Theoretical and Computational Chemistry; Catalysis; Chemical Engineering and Industrial Chemistry; Acid Catalysis; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64de822801042bc1cc38ecad/original/sulfurous-zeosils-for-dehydra-decyclization-of-tetrahydrofuran-to-renewable-butadiene.pdf |
6717fa2a12ff75c3a137857a | 10.26434/chemrxiv-2024-v3s5m | Tailoring Chloride Solid Electrolytes for Reversible Redox | Solid-state electrolytes enable next-generation batteries that can theoretically deliver higher energy densities while improving device safety. However, when fabricating cathodes for all-solid-state batteries, solid-state electrolytes must be combined with the active materials in high weight fractions in order to achieve sufficient ionic percolation within the cathode composite. This requirement drastically hinders the practicality of solid-state batteries as the solid-state electrolyte is conventionally designed to be electrochemically inactive and is effectively electrochemical ‘deadweight’, lowering both the gravimetric and volumetric energy density of the cell. In this work, a well-known solid-state electrolyte, Na2ZrCl6, is modified by aliovalent substitution of inactive Zr4+ cations with redox-active M5+ (M = Nb or Ta) cations to create a series of Na2–xMxZr1–xCl6 solid-solutions that possess both high ionic conductivities and active sites for Na+ storage. The Na+ intercalation mechanisms of these solid-solution materials, in addition to the NaMCl6 end-member materials, are elucidated in this work. It was discovered that both the niobium- and tantalum-containing chlorides exhibit rather high electrochemical potentials (2.2–2.8 V vs. Na9Sn4), making them ideal catholytes to pair with commonly used oxide cathode materials like NaCrO2. This synergistic pairing leads to a cathode composite with an 83–102% increase in energy density and 39–81% improvement in areal discharge capacity compared to a redox-innocent solid electrolyte. This approach highlights the benefits of designing and employing redox-active solid-state electrolytes that can reversibly intercalate charge-carrying cations, opening up a broad new avenue for solid-state electrolyte discovery and solid-state battery design. | Phillip Ridley; George Duong; Sarah Ko; Grayson Deysher; Jin An Sam Oh; Kent Griffith; Ying Shirley Meng | Materials Science; Inorganic Chemistry; Energy; Electrochemistry; Solid State Chemistry; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2024-10-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6717fa2a12ff75c3a137857a/original/tailoring-chloride-solid-electrolytes-for-reversible-redox.pdf |
6262af886c989c0776c19272 | 10.26434/chemrxiv-2022-wxqb2 | Highly Diastereo- and Branched-Selective Rearrangement of Substituted N-Alloc-N-Allyl Ynamides via Pd-Auto-Tandem Catalysis | An auto-tandem catalytic, branched-selective rearrangement of substituted N-alloc-N-allyl ynamides was developed. This reaction provides ready access to complex quaternary nitrile products with vinylogous stereocenters in excellent diastereoselectivity, including the formation of contiguous all-carbon quaternary centers. The stereochemical outcome is determined via a Pd(0) catalyzed dipolar ketenimine aza-Claisen rearrangement inside a deep cleft on the catalyst. Computational studies exemplify the key role ligand geometry plays throughout the reaction coordinate in this previously unreported mechanism. This study provides new reaction pathways for both π-allyl and sigmatropic rearrangements. | Matthew Cook; Oliver Jackson; Ksenia Stankevich | Organic Chemistry; Catalysis; Organometallic Chemistry; Organic Synthesis and Reactions; Stereochemistry; Reaction (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2022-04-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6262af886c989c0776c19272/original/highly-diastereo-and-branched-selective-rearrangement-of-substituted-n-alloc-n-allyl-ynamides-via-pd-auto-tandem-catalysis.pdf |
63713580afea7fd41aa3e560 | 10.26434/chemrxiv-2022-ncgck-v4 | Liquid crystal templates of mesoporous silica materials | The paper considers the mesophases of lyotropic liquid crystals and their role in creating the scaffold of mesoporous silica materials. It was in 1992 that a Mobil Research group disclosed a method to produce silica particles having a regular network of pores with hexagonal and cubic symmetries. The method was proposed as based on a liquid-crystal 'templating' mechanism. Since the symmetries resulting from the templating of silica scaffolds are those observed in the mesophases of lyotropic liquid crystals, the Mobil Research group supposed the presence of a mesophase directly in a stage of the templating mechanism. Here we discuss the method as it was reported in 1992 and what is today defined as a true liquid-crystal templating approach. It will be stressed that, in any case, the templating is a surfactant-assisted method, that can be better defined as supramolecular templating method. The template mainly happens in the form of a modified Stöber process. In this framework, the cubic phases of liquid crystals will be analyzed in depth. The related surfaces with zero mean curvature will be discussed in detail. Among them the gyroid will by approached through a Ginzburg-Landau model too. | Amelia Carolina Sparavigna | Materials Science; Liquid Crystals; Nanostructured Materials - Materials; Surfactants | CC BY NC ND 4.0 | CHEMRXIV | 2022-11-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63713580afea7fd41aa3e560/original/liquid-crystal-templates-of-mesoporous-silica-materials.pdf |
66bfff4df3f4b0529023946e | 10.26434/chemrxiv-2024-srqv5-v2 | A Chiral Nanohoop as Highly Efficient Asymmetric Organocatalyst | Chiral phosphoric acids are privileged organocatalysts that have been shown to facilitate a large variety of asymmetric transformations. In recent years, the BINOL scaffold has been equipped with large aromatic groups and transformed into dimeric imidodiphosphates to im-prove both chiral induction and catalyst turnover by tuning pKa and creating a confined space around the catalytic center. In this work, we report an alternative approach for achieving such a confinement effect within the cavity of a chiral, shape-persistent “carbon nanohoop” mac-rocycle. We integrated a BINOL-derived phosphoric acid into the [9]cycloparaphenylene (CPP) scaffold and employed the nanohoop as organocatalyst for the asymmetric transfer hydrogenation of quinolines. We found that the chiral macrocycle shows excellent catalytic activity with near-quantitative yields and enantioselectivities up to 96% ee, which is far supe-rior to comparable non-cyclic reference catalysts. While the scope for quinolines bearing aromatic substituents is wide, we made the counterintuitive observation that the macrocyclic catalyst is not active for smaller alkyl-substituted substrates, which indicates that highly spe-cific non-covalent effects determine the reaction outcome within the nanohoop cavity. These results suggest that outstanding selectivities can be achieved by endowing organocatalysts not only with supramolecular binding sites but also with unusual topologies. | Max von Delius; Adriana Sacristán-Martín; Fabian Schwer; Thomas Pickl; Anika Lebzelter; Alexander Pöthig | Organic Chemistry; Catalysis; Supramolecular Chemistry (Org.); Homogeneous Catalysis; Organocatalysis | CC BY 4.0 | CHEMRXIV | 2024-08-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66bfff4df3f4b0529023946e/original/a-chiral-nanohoop-as-highly-efficient-asymmetric-organocatalyst.pdf |
60c759634c89193979ad4d69 | 10.26434/chemrxiv.14687463.v1 | Using a Coarse-Grained Modeling Framework to Identify Oligomeric Motifs with Tunable Secondary Structure | We describe a process to build and simulate coarse-grained oligomers using temperature replica exchange molecular dynamics and analyze them for thermodynamic and structural characteristics of cooperative folding transitions. We also introduce a Python package (cg_openmm) to carry out these simulations and analyses. We demonstrate the capabilities of cg_openmm on a simple helix-forming homo-oligomer, systematically varying sets of force field parameters and studying the effects on folding cooperativity and helix stability. We find that small changes to force field parameters in the homo-oligomer model can dramatically affect cooperativity, stability, and even lead to helix-to-helix transitions. This software package enables large-scale screening of potential foldamer molecules and will be highly useful in the broader effort of understanding secondary structure formation in terms of non-chemically specific features of molecular models. | Christopher Walker; Garrett Meek; Theodore Fobe; Michael R. Shirts | Computational Chemistry and Modeling | CC BY 4.0 | CHEMRXIV | 2021-05-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c759634c89193979ad4d69/original/using-a-coarse-grained-modeling-framework-to-identify-oligomeric-motifs-with-tunable-secondary-structure.pdf |
60c74844842e65f4c6db2b4c | 10.26434/chemrxiv.11871837.v1 | Mass Spectrometry-Based Identification of Ortho-, Meta- and Paraisomers Using Infrared Ion Spectroscopy | Distinguishing positional isomers, such as compounds having different substitution patterns on an aromatic ring, presents a significant challenge for mass spectrometric analyses and is a frequently encountered difficulty in, for example, drug metabolism research. Here, we demonstrate infrared ion spectroscopy (IRIS) as a promising new mass spectrometry-based technique that easily differentiates between positional isomers of disubstituted phenyl-containing compounds. By analyzing different substitution patterns over several sets of isomeric compounds, we show that IRIS produces a highly consistent and distinct pattern of IR bands, especially in the range between 650 and 900 cm<sup>-1</sup>, that are mostly independent of the specific chemical functionality contained in the substituent group. These patterns are accurately predicted by quantum-chemically computed IR spectra and correspond well with tabulated IR group-frequencies known from conventional absorption spectroscopy. Therefore, we foresee that this method will be generally applicable to disubstituted phenyl-containing compounds and that direct interpretation of experimental IRIS spectra in terms of ortho-, meta- or para-substitution is possible, even without comparison to experimental or computationally predicted reference spectra. Strategies for the analysis of larger compounds having more congested IR spectra as well as of compounds having low (electrospray) ionization efficiencies are presented in order to demonstrate the broad applicability of this methodology.<br /> | Rianne E. van Outersterp; Jonathan Martens; Giel Berden; Valerie Koppen; Filip Cuyckens; Jos Oomens | Mass Spectrometry | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74844842e65f4c6db2b4c/original/mass-spectrometry-based-identification-of-ortho-meta-and-paraisomers-using-infrared-ion-spectroscopy.pdf |
6696e0505101a2ffa89105c8 | 10.26434/chemrxiv-2024-pjklk | Proteo-SAFARI: An R Application for Identification of Fragment Ions in Top-Down MS/MS Spectra of Proteins | Proteo-SAFARI is a Shiny Application for Fragment Assignment by Relative Isotopes, an R-based software application designed for identification of protein fragment ions directly in the m/z domain. This program provides an open-source, user-friendly application for identification of fragment ions from a candidate protein sequence with support for custom covalent modifications and various visualizations of identified fragments. Additionally, Proteo-SAFARI includes a nonnegative least square fitting approach to determine the contributions of various hydrogen shifted fragment ions (a+1, x+1, y-1, y-2) observed in UVPD mass spectra which exhibit overlapping isotopic distributions. To show its utility, Proteo-SAFARI is applied to various MS/MS spectra of intact proteins, including proteins exhibiting dynamic hydrogen shifts in y ions, ubiquitin charge-reduced to the 1+ charge state, and a large protein recorded in full profile mode. Proteo-SAFARI is available at: github.com/mblanzillotti/Proteo-SAFARI. | Michael Lanzillotti; Sean Dunham; Kyle Juetten; Jennifer Brodbelt | Analytical Chemistry; Mass Spectrometry | CC BY 4.0 | CHEMRXIV | 2024-07-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6696e0505101a2ffa89105c8/original/proteo-safari-an-r-application-for-identification-of-fragment-ions-in-top-down-ms-ms-spectra-of-proteins.pdf |
67d2bcd381d2151a02380282 | 10.26434/chemrxiv-2025-46zsr | Active Sites Engineering through Palladium-Phosphorus Synergy for Heterogeneously-Catalyzed Alkoxycarbonylation Reactions | Crystalline palladium phosphide (Pd3P) nanoparticles on silica were investigated for the alkoxycarbonylation of aryl halides, providing a strategic approach for designing high-performance carbonylation catalysts. The synthesized Pd3P/SiO2 (5 wt.%) catalyst was characterized via PXRD, HAADF-STEM, HRTEM, EDX, CO chemisorption and ICP-AES analysis. The incorporation of phosphorus into the palladium matrix, which results in the formation of a Pd3P phase, enhanced the intrinsic catalytic activity in the alkoxycarbonylation of aryl halides by more than two-fold compared to a traditional purely Pd-based heterogeneous catalyst. Moreover, Pd3P/SiO2 (5 wt.%) outperformed many reported heterogeneous catalysts as well as some commonly used homogeneous catalysts. The exceptional performance of palladium phosphide nanoparticles can be attributed to highly active and uniformly distributed Pd sites separated by phosphorus. This work highlights the potential of element synergy in developing highly efficient carbonylation catalysts by exploring Pd-P system in the alkoxycarbonylation reaction. | Arjun Neyyathala; Felix Jung; Claus Feldmann; Stephan A. Schunk; Schirin Hanf | Materials Science; Inorganic Chemistry; Catalysis; Catalysts; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67d2bcd381d2151a02380282/original/active-sites-engineering-through-palladium-phosphorus-synergy-for-heterogeneously-catalyzed-alkoxycarbonylation-reactions.pdf |
63a5d1ffa53ea69e935559e2 | 10.26434/chemrxiv-2022-rkm8l-v2 | Interplay of static and dynamic disorder in the mixed-metal chalcohalide Sn₂SbS₂I₃ | Chalcohalide mixed-anion crystals have seen a rise in interest as ‘perovskite-inspired materials’ with the goal of combining the ambient stability of metal chalcogenides with the exceptional optoelectronic performance of metal halides. Sn₂SbS₂I₃is a promising candidate, having achieved a photovoltaic power conversion efficiency above 4%. However, there is uncertainty over the crystal structure and physical properties of this crystal family. Using a first-principles cluster expansion approach, we predict a disordered room temperature structure, comprising both static and dynamic cation disorder on different crystallographic sites. These predictions are confirmed using single-crystal X-ray diffraction. Disorder leads to a lowering of the bandgap from 1.8 eV at low temperature to 1.5 eV at the experimental annealing temperature of 573 K. Cation disorder tailors the bandgap, allowing for targeted application for this class of materials in optoelectronics. | Adair Nicolson; Joachim Breternitz; Seán R. Kavanagh; Yvonne Tomm; Kazuki Morita; Alexander G. Squires; Michael Tovar; Aron Walsh; Susan Schorr; David O. Scanlon | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-12-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63a5d1ffa53ea69e935559e2/original/interplay-of-static-and-dynamic-disorder-in-the-mixed-metal-chalcohalide-sn2sb-s2i3.pdf |
64230e9b91074bccd06f845f | 10.26434/chemrxiv-2023-lf181-v2 | Engineering Host-Guest Interactions in Organic Framework Materials for Drug Delivery | Metal-organic frameworks (MOF) and covalent organic frameworks (COFs) are promising nanocarriers for targeted drug delivery. Noncovalent interactions between frameworks and drugs play a fundamental role in the therapeutic uptake and release of the latter. However, the scope of framework functionalisations and deliverable drugs remains underexplored. Using a multilevel approach combining molecular docking and density functional theory, we show for a range of drugs and frameworks that experimentally reported release metrics are in good agreement with the in silico computed host-guest interaction energies. Functional groups within the framework significantly impact the strength of these host-guest interactions, while a given framework can serve as an efficient delivery agent for drugs beyond the prototypical few. Our findings identify the interaction energy as a reliable and relatively easy to compute descriptor of organic framework materials for drug delivery, able to facilitate their high-throughput screening and targeted design towards extended-release times. | Michelle Ernst; Ganna Gryn'ova | Theoretical and Computational Chemistry; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64230e9b91074bccd06f845f/original/engineering-host-guest-interactions-in-organic-framework-materials-for-drug-delivery.pdf |
60c74851ee301c44ffc79843 | 10.26434/chemrxiv.11890194.v1 | Cooperative and Fully Reversible Photocatalytic Colour Switching Activation in Graphene-Copper-TiO2 Nanoparticles | <p>Nanostructured systems showing reversible
colour switching are envisaged to play a significant role in photo-switches,
photo-optical sensors, smart windows, displays, optical storage memories. Most
of the materials exhibiting reversible colour switching are organic compounds. However,
their UV-light activation, low thermal and chemical stability, as well as harmful
synthesis methods, are of limit for their extensive use. In this research, we
have created an inorganic switchable photochromic material exploiting: (i) TiO<sub>2</sub>
ability of creating an exciton upon excitation, (ii) copper as the chromophore, and (iii) graphene’s extraordinarily high electron mobility. Our material showed itself
to be able to work under visible-light, its photochromic property being three
times faster than conventional titania based photochromic materials, reaching a
stable change in colouration after only 30 mins of visible-light irradiation (<i>versus</i> > 120 min in conventional
Cu-TiO<sub>2</sub>). With the addition of just 1 wt% graphene, the material
exhibited a staggeringly stable photochromic switching over repeated cycles. These
results relate to the best previously reported values for any form of TiO<sub>2</sub>-based
photochromic material. This is therefore an excellent candidate for smart self-cleaning
windows, and other chromic devices and applications.</p> | David Maria Tobaldi; Luc Lajaunie; Dana Dvoranova; Bruno Figueiredo; Maria Paula Seabra; José Calvino; Vlasta Brezova; Joao Antonio Labrincha | Composites; Optical Materials; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74851ee301c44ffc79843/original/cooperative-and-fully-reversible-photocatalytic-colour-switching-activation-in-graphene-copper-ti-o2-nanoparticles.pdf |
66ee6f8d12ff75c3a1fdd7b9 | 10.26434/chemrxiv-2024-5058f | Catalytic function of zinc finger proteins against amyloid- amyloidogenesis | Zinc finger (ZF) proteins are integral to neurological processes by mediating biomolecular interactions and regulating gene expression. Despite their implication in neurodegenerative diseases, the precise contribution of ZF proteins to disease pathology remains unclear. Here we show the direct binding of the ZF protein PARIS(ZF2–4) with amyloid-beta (Abeta) as well as its catalytic function in reprofiling Abeta aggregation and cytotoxicity, a key contributor to Alzheimer’s disease. The complex formation between PARIS(ZF2–4) and Abeta promotes the amorphous aggregation of Abeta, which reduces its interaction with cell membranes and prevents the formation of toxic oligomers and fibrils, thus alleviating A-induced cytotoxicity. Through sequence-based reactivity and mechanistic analyses employing fragments and variants, we identify structural motifs critical for PARIS(ZF2–4)’s function. These findings demonstrate a novel modulative role of ZF proteins in Abeta amyloidogenesis, highlighting a sequence–reactivity relationship that offers insights into potential therapeutic avenues for neurodegenerative disorders. | Seongmin Park; Yunha Hwang; Yuxi Lin; Jimin Kwak; Eunju Nam; Jiyeon Han; Hyun Goo Kang; Jiyong Park; Young-Ho Lee; Seung Jae Lee; Mi Hee Lim | Biological and Medicinal Chemistry; Biochemistry; Biophysics; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66ee6f8d12ff75c3a1fdd7b9/original/catalytic-function-of-zinc-finger-proteins-against-amyloid-amyloidogenesis.pdf |
60c74fcabb8c1a04963dba18 | 10.26434/chemrxiv.12941606.v1 | Interaction Analyses on SARS-CoV-2 Spike Protein Based on Large-Scale Correlated Fragment Molecular Orbital Calculations | At the stage of SARS-CoV-2 infection to human cell, the spike protein consisting of three chains, A, B and C, with a total of 3.3 thousand residues plays the key role, and thus its nature have attracted considerable interests. Here, we report interaction analyses on the spike protein of both closed (PDB-ID: 6VXX) and open (6VYB) structures, based on large-scale fragment molecular orbital (FMO) calculations at the level of up to the fourth-order Møller-Plesset perturbation with singles, doubles and quadruples (MP4(SDQ)). Inter-chain interaction energies were evaluated for both structures, and mutual comparison indicated considerable losses of stabilization energies in the open structure, especially in the receptor binding domain (RBD) of chain-B. By two separate calculations for the RBD complexes with angiotensin converting enzyme 2 (ACE2) (6M0J) and B38 Fab antibody (7BZ5), it was found that this stabilization loss of RBD was partially compensated by the binding with ACE2 or antibody. | Kazuki Akisawa; Ryo Hatada; Koji Okuwaki; Yuji Mochizuki; Kaori Fukuzawa; Yuto Komeiji; Shigenori Tanaka | Computational Chemistry and Modeling; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74fcabb8c1a04963dba18/original/interaction-analyses-on-sars-co-v-2-spike-protein-based-on-large-scale-correlated-fragment-molecular-orbital-calculations.pdf |
60c749c6bb8c1a546f3daec1 | 10.26434/chemrxiv.12102894.v1 | Multidisciplinary Preclinical Investigations on Three Oxamniquine Analogues as Novel Treatment Options for Schistosomiasis | <div>Schistosomiasis is a disease of poverty affecting millions of people. Praziquantel (PZQ), with its </div><div>strengths and weaknesses, is the only treatment available. We previously reported 3 lead </div><div>compounds derived from oxamniquine (OXA), an old antischistosomal drug: ferrocene‐containing </div><div>(Fc‐CH2‐OXA), ruthenocene‐containing (Rc‐CH2‐OXA) and benzene‐containing (Ph‐CH2‐OXA). </div><div>These derivatives showed excellent in vitro activity against both Schistosoma mansoni and S. </div><div>haematobium larvae and adult worms, and in vivo against S. mansoni. Encouraged by these </div><div>promising results, we followed a guided drug discovery process and report in this investigation on </div><div>metabolic stability studies, in vivo studies, computational simulations, and formulation studies. </div><div>Molecular dynamics simulations supported the in vitro results on the target protein. Though all </div><div>three compounds were poorly stable within an acidic environment, they were only slightly cleared </div><div>in the in vitro liver model. This is likely the reason as to why the promising in vitro activity did not </div><div>translate to in vivo activity. This limitation could not be saved by the formulation of lipid </div><div>nanocapsules as an intent to improve the in vivo activity. Further studies should focus on increasing </div><div>the compound’s bioavailability, in order to reach an active concentration in the parasite’s </div><div>microenvironment. </div> | Valentin Buchter; Yih Ching Ong; François Mouvet; Abdallah Ladaycia; Elise Lepeltier; Ursula Rothlisberger; Jennifer Keiser; Gilles Gasser | Bioinorganic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c749c6bb8c1a546f3daec1/original/multidisciplinary-preclinical-investigations-on-three-oxamniquine-analogues-as-novel-treatment-options-for-schistosomiasis.pdf |
6585136566c1381729c3cddb | 10.26434/chemrxiv-2023-lzgfb-v2 | Identification of hydrocarbon sulfonates as previously overlooked transthyretin ligands in the environment | Incidences of thyroid disease, which has long been hypothesized to be partially caused by exposure to thyroid hormone disrupting chemicals (TDCs), have rapidly increased in recent years. However, only ~1% of the binding activity of human transthyretin (hTTR), an important thyroid hormone transporter protein, can be explained by known TDCs. In this study, we aimed to identify the major hTTR ligands in Canadian indoor dust and sewage sludge by employing protein-guided nontargeted analysis. hTTR binding activities were detected in all 11 indoor dust and 9 out of 10 sewage sludge samples (median 458 and 1134 μg T4/g in dust and sludge, respectively) by the FITC-T4 displacement assay. Through employing protein Affinity Purification with Nontargeted Analysis (APNA), 31 putative hTTR ligands were detected including perfluorooctane sulfonate (PFOS). Two of the most abundant ligands were identified as hydrocarbon surfactants (e.g., dodecyl benzenesulfonate), which were confirmed by authentic chemical standards. Structure-activity relationships (SAR) of hydrocarbon surfactants were explored by investigating the binding activity of 11 hydrocarbon surfactants to hTTR. Optimal carbon chain length (C12-14) was found to achieve a high binding affinity. By employing de novo nontargeted analysis, another abundant ligand was surprisingly identified as a di-sulfonate fluorescent brightener, 4,4'-Bis(2-sulfostyryl)biphenyl sodium (CBS). CBS was validated as a nM-affinity hTTR ligand with an IC50 of 345 nM. In total, hydrocarbon surfactants and fluorescent brightener could explain 1.92-17.0% and 5.74-54.3% of hTTR binding activities in dust and sludge samples, respectively, whereas PFOS only contributed <0.0001% to the activity. Our study revealed for the first time that hydrocarbon sulfonates are previously overlooked hTTR ligands in the environment. | Yufeng Gong; Jianxian Sun; Holly Barrett; Hui Peng | Earth, Space, and Environmental Chemistry; Environmental Science | CC BY NC ND 4.0 | CHEMRXIV | 2023-12-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6585136566c1381729c3cddb/original/identification-of-hydrocarbon-sulfonates-as-previously-overlooked-transthyretin-ligands-in-the-environment.pdf |
675d45f3f9980725cf0b9c12 | 10.26434/chemrxiv-2024-7sps4 | Chemical degradations of kraft pulp carbohydrates molar mass distributions and their consequences on fibres strength | Industrial oxygen-delignified and fully-bleached hardwood kraft pulps were treated with chemicals to provoke carbohydrates depolymerisation: ozone, hypochlorous acid, and cellulase. The degrees of polymerisation (DP) of cellulose obtained by pulp viscosity measurement in Cuen and by size-exclusion chromatography after direct dissolution in DMAc/LiCl indicated the extent of the chemical degradation inflicted to the fibres. Molar mass distributions (MMD) described the carbohydrates depolymerisation patterns. Fibre strength was assessed by measuring the zero-span tensile index at never-dried state. Fibre strength deterioration seemed to be mainly driven by the topochemistry of the cellulose degradation (homogeneous or localised), rather than by its intensity usually measured as an average DP loss. In fact, depolymerisation by cellulase was found critically detrimental to fibres strength whereas ozone and hypochlorous acid induced little harm to the fibres despite a significant cellulose depolymerisation. According to these results, in line with several past studies, fibre strength measurements should be performed systematically as the sole pulp viscosity is an inadequate indicator. Alternatively, albeit being insufficient strength predictors on their own MMD can give valuable insight on the topochemistry of the cellulose degradation, a key aspect when monitoring fibre strength preservation during pulping and bleaching. | Etienne Montet; Dominique Lachenal; Christine Chirat | Materials Science; Polymer Science; Chemical Engineering and Industrial Chemistry; Fibers; Cellulosic materials | CC BY 4.0 | CHEMRXIV | 2024-12-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/675d45f3f9980725cf0b9c12/original/chemical-degradations-of-kraft-pulp-carbohydrates-molar-mass-distributions-and-their-consequences-on-fibres-strength.pdf |
66e000fc51558a15ef93a78d | 10.26434/chemrxiv-2024-0s03g | Mechanistic Investigations of a Hydrogen-Evolving Cobalt Diimine-Dioxime Complex in an Oxygen Environment: Roles of Secondary Coordination Sphere, Brønsted Acid, and Axial Ligand | The development of molecular electrocatalysts for fuel-forming reactions, such as the hydrogen-evolving reaction (HER) or the reduction of carbon dioxide, is generally hindered by their susceptibility to dioxygen in practical applications, which results from the concomitant formation of reactive oxygen species. The concept of a secondary coordination sphere (SCS) has been widely adopted in designing molecular electrocatalysts to promote the aforementioned energy-conversion reactions. The impact of this supernumerary interaction through the SCS on the oxygen-tolerant properties of molecular electrocatalysts is less explored. A HER electrocatalyst, cobalt diimine-dioxime complex, is one of the metal complexes designed by the concept of SCS to facilitate HER and retain its reactivity in an oxygen environment. Nevertheless, the mechanism underlying its oxygen tolerance remains unclear. In this study, mechanistic studies of how this complex undergoes HER under aerobic conditions were conducted. The results reveal that the oxygen reduction reaction (ORR) predominates in the presence of molecular oxygen. Further studies uncover the intramolecular proton transfer through SCS and intermolecular proton transfer from exogenous proton sources mutually dictate the product selectivity of ORR between H2O2 and H2O, thereby determining the stability of the complex under HER. In addition, the choice of labile ligands has emerged as a useful factor in enhancing oxygen tolerance. These findings provide valuable design principles for developing oxygen-tolerant molecular catalysts and shed light on how the interplay of proton transfer routes between the secondary coordination sphere and exogenous pathway can impact reactivity and product selectivity. | Yu-Syuan Tsai; Yu-Wei Chen; Charasee Laddika Dayawansa; Hsuan Chang; Wen-Ching Chen; Jiun-Shian Shen; Tiow-Gan Ong; Glenn P. A. Yap; Vincent C.-C. Wang | Inorganic Chemistry; Catalysis; Electrocatalysis; Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66e000fc51558a15ef93a78d/original/mechanistic-investigations-of-a-hydrogen-evolving-cobalt-diimine-dioxime-complex-in-an-oxygen-environment-roles-of-secondary-coordination-sphere-br-nsted-acid-and-axial-ligand.pdf |
664cab3b91aefa6ce1976a1e | 10.26434/chemrxiv-2024-pwgq6-v2 | Screening the ToxCast Chemical Libraries for Binding to Transthyretin | Transthyretin (TTR) is one of the serum binding proteins responsible for transport of thyroid hormones (TH) to target tissue and for maintaining the balance of available TH. Chemical binding to TTR and subsequent displacement of TH has been identified as an endpoint in screening chemicals for potential disruption of the thyroid system. To address the lack of data regarding chemicals binding to TTR, we optimized an in vitro assay utilizing the fluorescent probe 8-anilino-1-napthalenesulfonic acid (ANSA) and the human protein TTR to screen over 1,500 chemicals from the U.S. EPA’s ToxCast ph1_v2, ph2, and e1k libraries utilizing a tiered approach. Testing of a single high concentration (target 100 µM) resulted in 888 chemicals with 20% or greater activity based on displacement of ANSA from TTR. Of these, 282 chemicals had activity of 85% or greater and were further tested in 12-point concentration-response with target concentrations ranging from 0.015-100µM. An EC50 was obtained for 276 of these 282 chemicals. To date, this is the largest set of chemicals screened for binding to TTR. Utilization of this assay is a significant contribution towards expanding the suite of in vitro assays used to identify chemicals with the potential to disrupt thyroid hormone homeostasis. | Stephanie A. Eytcheson; Alexander D. Zosel; Jennifer H. Olker; Michael W. Hornung; Sigmund J. Degitz | Biological and Medicinal Chemistry; Cell and Molecular Biology; Environmental biology | CC BY NC 4.0 | CHEMRXIV | 2024-05-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/664cab3b91aefa6ce1976a1e/original/screening-the-tox-cast-chemical-libraries-for-binding-to-transthyretin.pdf |
6677c1865101a2ffa848be70 | 10.26434/chemrxiv-2024-d0j6v-v3 | Correlation between mechanical properties and ionic conductivity of sodium superionic conductors: a relative density-dominant relationship | Sodium superionic conductors (NASICON) are pivotal for the functionality and safety of solid-state sodium batteries. Their mechanical properties and ionic conductivity are key performance metrics, yet their correlation remains inadequately understood. Addressing this gap is vital for concurrent enhancements in both properties. This study summarizes recent literature on the sintered polycrystalline NASICON solid electrolyte Na1+xZr2SixP3-xO12 (NZSP, 0≤x≤3), focusing on its mechanical properties and ionic conductivity, and identifies a positive correlation between these properties at ambient temperatures. Microstructural analysis reveals that a range of factors, including relative density, grain size, secondary phases, and crystal structures, significantly influence the properties of NZSP. Notably, an increase in relative density uniquely contributes to simultaneous enhancements in both hardness and ionic conductivity. Consequently, future research should prioritize enhancing the relative density of NZSP, potentially by employing advanced sintering techniques such as spark plasma sintering (SPS) and microwave-assisted sintering. The correlation between mechanical properties and ionic conductivity observed in NZSP is also evident in other oxide solid electrolytes, such as garnet Li7La3Zr2O12 (LLZO). This investigation not only suggests a potential linkage between these crucial properties but also guides subsequent strategies for refining polycrystalline oxide solid electrolytes for advanced battery technologies. | Eric Jianfeng Cheng; Tao Yang ; Yuanzhuo Liu ; Linjiang Chai ; Regina Garcia-Mendez ; Eric Kazyak ; Zhenyu Fu ; Guoqiang Luo ; Fei Chen ; Ryoji Inada ; Vlad Badilita ; Huanan Duan ; Ziyun Wang ; Jiaqian Qin ; Hao Li ; Shin-ichi Orimo ; Hidemi Kato | Materials Science; Inorganic Chemistry; Energy; Ceramics; Elastic Materials; Energy Storage | CC BY NC 4.0 | CHEMRXIV | 2024-06-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6677c1865101a2ffa848be70/original/correlation-between-mechanical-properties-and-ionic-conductivity-of-sodium-superionic-conductors-a-relative-density-dominant-relationship.pdf |
60e49bf2a4e06b5d657020d8 | 10.26434/chemrxiv-2021-clthv | 1- and 2-Azetines via Visible Light-Mediated [2+2]-Cycloadditions of Alkynes and Oximes | Azetines, four-membered unsaturated nitrogen-containing heterocycles, hold great potential for drug design and development, but remain underexplored due to challenges associated with their synthesis. We report an efficient, visible light-mediated approach to-wards 1- and 2-azetines relying on alkynes and the unique triplet state reactivity of oximes, specifically 2-isoxazolines. While 2-azetine products are accessible upon intermolecular [2+2]-cycloaddition via triplet energy transfer from a commercially available iridi-um photocatalyst, the selective formation of 1-azetines proceeds upon a second, consecutive, energy transfer process. Mechanistic studies are consistent with a stepwise reaction mechanism via N-O bond homolysis following the second energy transfer event to result in the formation of 1-azetine products. Characteristic for this method is its operational simplicity, mild conditions and modular approach that allows for the synthesis of functionalized azetines and tetrahydrofurans via in situ hydrolysis from readily available precursors. | Corinna Schindler; Emily Wearing; Dominique Blackmun; Marc Becker | Catalysis; Photocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2021-07-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60e49bf2a4e06b5d657020d8/original/1-and-2-azetines-via-visible-light-mediated-2-2-cycloadditions-of-alkynes-and-oximes.pdf |
61d7130edb142e79ccb5819d | 10.26434/chemrxiv-2022-rf825 | Direct Diels-Alder reaction of chitin derived 3-acetamido-5-acetylfuran | The Diels-Alder (DA) reaction of biomass derived furans is an emerging technology for the preparation of new molecular entities and “drop-in” commodity chemicals. In this work we address the challenge of the direct use of electron-poor furanic platforms as dienes through the use of an unexplored chitin derived furan, 3-acetamido-5-acetylfuran (3A5AF). The 3-acetamido group promoted a remarkable increase in the kinetics of the DA allowing for the preparation of 7-oxanorbornenes (7-ONB) at 50 ºC. Partial hydrolysis of the enamide to hemi-acylaminals was possible upon fine tuning of the reaction conditions, disabling retro-DA processes. Finally, DA reaction of the reduced form of 3A5AF allowed quantitative formation of 7-ONB in aqueous condition after 10 minutes. Certanly these are the first steps for expanding the toolbox of chitin derived 3A5AF as diene. | Rafael Gomes; Juliana Pereira; João Ravasco; João Vale; Fausto Queda | Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2022-01-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61d7130edb142e79ccb5819d/original/direct-diels-alder-reaction-of-chitin-derived-3-acetamido-5-acetylfuran.pdf |
60d2edfdfca4906986c8a726 | 10.26434/chemrxiv-2021-2wzq7 | Excited States of Xanthophylls Revisited:
Towards the Simulation of Biologically Relevant
Systems | Xanthophylls are an important class of oxygen containing carotenoids, which play a fundamental role both in light harvesting pigment-protein complexes and in many other photo-responsive proteins. The complexity of the manifold of the electronic states and the large sensitivity to the environment still prevent a clear and coherent interpretation of their pho-tophysics and photochemistry. In this Letter, we first apply cutting-edge ab-initio methods
(CC3, DMRG/NEVPT2) on model C2h keto-carotenoids to critically asses the performances +of single and multi-reference methods. We then lift symmetry restrictions and extend the tested methods to time dependent DFT and Semiempirical CI (SECI). From this analysis, we
demonstrate that SECI can indeed represent an optimal method for describing light-induced processes of xanthophylls in biologically relevant systems. As an example, we investigate canthaxanthin in the Orange Carotenoid Protein showing that the conical intersections between excited states ... | Mattia Bondanza; Denis Jacquemin; Benedetta Mennucci | Theoretical and Computational Chemistry; Physical Chemistry; Biological and Medicinal Chemistry; Chemical Biology; Computational Chemistry and Modeling; Biophysical Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-06-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60d2edfdfca4906986c8a726/original/excited-states-of-xanthophylls-revisited-towards-the-simulation-of-biologically-relevant-systems.pdf |
645862471ca6101a45f5c4db | 10.26434/chemrxiv-2023-v9jwh-v2 | Metal-organic frameworks meet Uni-MOF: a transformer-based gas adsorption detector | Gas separation is crucial for industrial production and environmental protection, with metal-organic frameworks(MOFs) offering a promising solution due to their tunable structural properties and chemical compositions. Traditional simulation approaches, such as molecular dynamics, are complex and computationally demanding. Although feature engineering-based machine learning methods perform better, they are susceptible to overfitting because of limited labeled data. Furthermore, these methods are typically designed for single tasks, such as predicting gas adsorption capacity under specific conditions, which restricts the utilization of comprehensive datasets including all adsorption capacities. To address these challenges, we propose Uni-MOF, an innovative framework for large-scale, three-dimensional MOF representation learning, designed for universal multi-gas prediction. Specifically, Uni-MOF serves as a versatile "gas adsorption detector" for MOF materials, employing pure three-dimensional representations learned from over 631,000 collected MOF and COF structures. Our experimental results show that Uni-MOF can automatically extract structural representations and predict adsorption capacities under various operating conditions using a single model. For simulated data, Uni-MOF exhibits remarkably high predictive accuracy across all datasets. Impressively, the values predicted by Uni-MOF correspond with the outcomes of adsorption experiments. Furthermore, Uni-MOF demonstrates considerable potential for broad applicability in predicting a wide array of other properties. | Jingqi Wang; Jiapeng Liu; Hongshuai Wang; Guolin Ke; Linfeng Zhang; Jianzhong Wu; Zhifeng Gao; Diannan Lu | Materials Science; Nanostructured Materials - Materials | CC BY NC ND 4.0 | CHEMRXIV | 2023-05-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/645862471ca6101a45f5c4db/original/metal-organic-frameworks-meet-uni-mof-a-transformer-based-gas-adsorption-detector.pdf |
6100370e537d10434d7ff22e | 10.26434/chemrxiv-2021-gqfj4 | A chemoproteomics approach to profile phospholipase D-derived phosphatidyl alcohol interactions | Alcohol consumption leads to formation of phosphatidylethanol (PEth) via the transphosphatidylation activity of phospholipase D (PLD) enzymes. Though this non-natural phospholipid routinely serves as a biomarker of chronic alcoholism, its pathophysiological roles remain unknown. We use a minimalist diazirene alkyne alcohol as an ethanol surrogate to generate clickable, photoaffinity lipid reporters of PEth localization and lipid–protein interactions via PLD-mediated transphosphatidylation. We use these tools to visualize phosphatidyl alcohols in a manner compatible with standard permeabilization and immunofluorescence methods. We also use click chemistry tagging, enrichment, and proteomics analysis to define the phosphatidyl alcohol interactome. Our analysis reveals an enrichment of putative interactors at various membrane locations, and we validate one such interaction with the single-pass transmembrane protein basigin/CD147. This study provides a comprehensive view of the molecular interactions of phosphatidyl alcohols with the cellular proteome and points to future work to connect such interactions to potential pathophysiological roles of PEth. | Weizhi Yu; Jeremy Baskin | Biological and Medicinal Chemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2021-07-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6100370e537d10434d7ff22e/original/a-chemoproteomics-approach-to-profile-phospholipase-d-derived-phosphatidyl-alcohol-interactions.pdf |
60c74cb3567dfe3488ec51cc | 10.26434/chemrxiv.12401261.v2 | CNC-Milled Superhydrophobic Macroporous Monoliths for 3D Cell Culture | High-strength macroporous monoliths can be obtained by simply mixing boehmite nanofiber aqueous acetate dispersions with methyltrimethoxysilane. On the boehmite nanofiber-polymethylsilsesquioxane monoliths, we can fabricate structures smaller than a millimeter in size by computer numerical control (CNC) milling, resulting in a machined surface that is superhydrophobic and biocompatible. Using this strategy, we fabricated a superhydrophobic multiwell plate which holds water droplets to produce 3D cell culture environments for various cell types. We expect these superhydrophobic monoliths to have future applications in 3D tissue construction. | Gen Hayase; Daisuke Yoshino | Composites; Hybrid Organic-Inorganic Materials; Bioengineering and Biotechnology | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74cb3567dfe3488ec51cc/original/cnc-milled-superhydrophobic-macroporous-monoliths-for-3d-cell-culture.pdf |
6620bbf491aefa6ce1ccfdbc | 10.26434/chemrxiv-2024-95c09 | Spatio-Temporal Characterization of Water Diffusion Anomalies in Saline Solutions Using Machine Learning Force Field | Understanding the dynamics of water in salt solutions is a complex challenge that computational chemists have been addressing. Previously, force fields have encountered difficulties in fully capturing the detailed behaviors of water in the presence of various salts and concentrations, highlighting the necessity for more sophisticated approaches. The emergence of machine learning in computational chemistry, particularly through innovations like the Deep Potential Molecular Dynamics (DPMD), offers a promising alternative that closely aligns with the accuracy of first-principles methods. In this study, we utilized DPMD to explore the effects of salts on water dynamics, examining its performance in relation to ab-initio molecular dynamics, SPC/Fw, AMOEBA, and MB-Pol models. Our focus was on understanding water behavior in salt solutions through the lens of spatio-temporally correlated dynamics. We discovered that the ability of each model to accurately reflect water dynamics in salt solutions is closely tied to its approach to spatio-temporal correlation. This investigation not only highlights the advanced capabilities of MLFFs like DPMD in addressing the complexities of water-salt interactions but also broadens our understanding of the fundamental mechanisms governing these interactions. | Ji Woong Yu; Sebin Kim; Jae Hyun Ryu; Won Bo Lee; Tae Jun Yoon | Physical Chemistry; Physical and Chemical Properties; Solution Chemistry; Transport phenomena (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6620bbf491aefa6ce1ccfdbc/original/spatio-temporal-characterization-of-water-diffusion-anomalies-in-saline-solutions-using-machine-learning-force-field.pdf |
65cb8dae9138d2316109413e | 10.26434/chemrxiv-2024-sn9nd | a-Amination of Carbonyl Compounds Using Ammonia Under Oxidative Conditions | We herein report a method for the direct a-amination of different carbonyl compounds by using aqueous ammonium as the N-source. Upon using ammonia in combination with hypochlorites as simple oxidants under phase-transfer conditions it is possible to carry out the direct oxidative a-amination of cyclic b-ketoesters, oxindoles as well as malonitriles and malonates with good to excellent yields. Furthermore, a first proof-of-concept for an asymmetric variant by employing chiral ammonium salts was obtained. | Christopher Mairhofer; Katharina Röser; Mario Waser | Organic Chemistry; Catalysis; Organocatalysis | CC BY 4.0 | CHEMRXIV | 2024-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65cb8dae9138d2316109413e/original/a-amination-of-carbonyl-compounds-using-ammonia-under-oxidative-conditions.pdf |
63b5a637a53ea6a8f0634c95 | 10.26434/chemrxiv-2023-1646b-v2 | Chemoselective, oxidation-induced macrocyclization of tyrosine-containing peptides | Inspired by Nature’s wide range of oxidation-induced modifications to install cross-links and cycles at tyrosine (Tyr) and other phenol-containing residue side chains, we report a Tyr-selective strategy for the preparation of Tyr-linked cyclic peptides. This approach leverages N4-substituted 1,2,4-triazoline-3,5-diones (TADs) as azo electrophiles that react chemoselectively with the phenolic side chain of Tyr residues to form stable C–N1-linked cyclic peptides. In the developed method, a precursor 1,2,4-triazolidine-3,5-dione moiety, also known as a urazole, is readily constructed at any free amine revealed on a solid-supported peptide. Once prepared, the N4-substituted urazole peptide is selectively oxidized using mild, peptide-compatible conditions to generate an electrophilic N4-substituted TAD peptide intermediate that reacts selectively under aqueous conditions with internal and terminal Tyr residues to furnish Tyr-linked cyclic peptides. The approach demonstrates good tolerance of native residue side chains and enables access to cyclic peptides ranging from 3- to 11-residues in size (16- to 38-atom-containing cycles). The identity of the installed Tyr-linkage, a stable covalent C–N1 bond, was characterized using NMR spectroscopy. Finally, we applied the developed method to prepare biologically active Tyr-linked cyclic pep-tides bearing the integrin-binding RGDf epitope. | E. Dalles Keyes; Marcus C. Mifflin; Maxwell J. Austin; Brighton J. Alvey; Lotfa H. Lovely; Andriea Smith; Bethany A. Buck-Koehntop; Andrew G. Roberts | Biological and Medicinal Chemistry; Organic Chemistry; Organic Synthesis and Reactions; Chemical Biology | CC BY 4.0 | CHEMRXIV | 2023-01-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63b5a637a53ea6a8f0634c95/original/chemoselective-oxidation-induced-macrocyclization-of-tyrosine-containing-peptides.pdf |
60c755a4bb8c1a4f423dc461 | 10.26434/chemrxiv.14138198.v1 | Chemically Fueled Block Copolymer Self-Assembly into Transient Nanoreactors | In chemically fueled
supramolecular materials, molecular self-assembly is coupled to a fuel-driven chemical
reaction cycle. The fuel-dependence makes the material dynamic and endows it with
exciting properties like adaptivity and autonomy. In contrast to the large work on the
self-assembly of small molecules, we herein designed a diblock copolymer, which self assembles into transient micelles when coupled to a fuel-driven chemical reaction
cycle. Moreover, we used these transient block copolymer micelles to locally increase
the concentration of hydrophobic reagents and thereby function as a transient
nanoreactor. | Michaela A. Würbser; Patrick Schwarz; Jonas Heckel; Alexander M. Bergmann; Andreas Walther; Job Boekhoven | Self-Assembly | CC BY NC ND 4.0 | CHEMRXIV | 2021-03-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c755a4bb8c1a4f423dc461/original/chemically-fueled-block-copolymer-self-assembly-into-transient-nanoreactors.pdf |
60c73e56ee301c9bd5c786eb | 10.26434/chemrxiv.6854486.v1 | Hue Parameter Fluorescence Identification of Edible Oils with a Smartphone | Food-fraud can be highly lucrative and high accuracy
authentication of various foodstuffs is becoming essential. Olive oil is one of
the most investigated food matrices, due to its high price and low production
globally, with recent food-fraud examples showing little or no high quality
olive oil in the tested oils. Here a simple method using a 405 nm-LED
flashlight and a smartphone is developed for edible oil authentication.
Identification is fingerprinted by intrinsic fluorescent compounds in the oils,
such as chlorophylls and poly-phenols. This study uses the hue parameter of
HSV-colorspace to authenticate 24 different edible oils of nine different types
and 15 different brands. For extra virgin olive oil all the nine samples are well
separated from the other oil samples. The rest of the samples were also well
type-distinguished by the hue parameter, which is complemented by hue-histogram
analysis. This opens up opportunities for low-cost and high-throughput
smartphone field-testing of edible oils on all levels of the production and
supply chain. | Aron Hakonen; Jonathon
E. Beves | Analytical Chemistry - General; Analytical Apparatus; Imaging; Food | CC BY NC 4.0 | CHEMRXIV | 2018-07-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e56ee301c9bd5c786eb/original/hue-parameter-fluorescence-identification-of-edible-oils-with-a-smartphone.pdf |
60c740639abda228e8f8bc9b | 10.26434/chemrxiv.7731305.v1 | Revisiting Glycerol Esterification with Acetic Acid over Amberlyst-35 via Statistically Designed Experiments: Overcoming Transport Limitations | Turnover rates for glycerol esterification with acetic acid over Amberlyst-35 were measured under different temperatures, reactants and active sites concentrations, and catalyst particle sizes. Data were collected in a batch reactor. Experiments were done following a sequence of factorial experimental designs. | Víctor Gabriel Baldovino Medrano; Karen V. Caballero; Hernando Guerrero-Amaya | Polymerization catalysts; Heterogeneous Catalysis; Nanocatalysis - Reactions & Mechanisms | CC BY NC ND 4.0 | CHEMRXIV | 2019-02-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c740639abda228e8f8bc9b/original/revisiting-glycerol-esterification-with-acetic-acid-over-amberlyst-35-via-statistically-designed-experiments-overcoming-transport-limitations.pdf |
65abae269138d23161584ea1 | 10.26434/chemrxiv-2023-fwlm5-v2 | Synthesis and Optical Property Modulation of Substituted [2,2]-paracylophanes through Through-Space Conjugation | 4,16-para-substituted [2,2] paracylophane with naphthalene (PCP⎼NAP), anthracene (PCP⎼ANTH), and tetraphenylethylene (PCP⎼TPE) as a new through-space conjugated dimers were prepared by the Suzuki–Miyaura cross-coupling reaction of 4,16-diboryl [2,2] paracyclophane and respective bromo derivative using Pd(PPh3)4 as a catalyst and KOH as a base. The synthesized compounds were fully characterized by NMR, HR-MS and their photophysical, and electrochemical properties were studied. The quantum yield of PCP⎼NAP, PCP⎼ANTH and PCP-TPE were calculated and estimated as 0.21, 0.50 and 0.31 respectively. PCP⎼TPE exhibited aggregation-induced emission characteristics when the water fraction was higher than 50% in the THF/water mixtures. PCP-ANTH and PCP-TPE were also characterized by X-ray Crystallography, obtained single crystal of PCP-ANTH crystalizes in centrosymmetric monoclinic space group C2/c. A single crystal of PCP-TPE crystallizes in the centrosymmetric triclinic space group P⎼1 with one molecule residing on the inversion centre. The observed properties of these π-stacked dimers were compared through through-space Conjugation and conjugation length in the structure. | Sushil Lambud; Anil Bhadke; Zahir Ali Siddiqui; Vaishali Chaudhari; Nagaiyan Sekar; Rajesh Bhosale; Sandeep More | Organic Chemistry; Organic Synthesis and Reactions; Materials Chemistry; Crystallography – Organic | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65abae269138d23161584ea1/original/synthesis-and-optical-property-modulation-of-substituted-2-2-paracylophanes-through-through-space-conjugation.pdf |
60c74f11bb8c1a6c653db868 | 10.26434/chemrxiv.12844301.v1 | N-Alkylation of 2-Methoxy-10H-Phenothiazine Revisited. A Facile Entry to Diversely N-substituted Phenothiazine-Coumarin Hybrid Dyes | <div><br /></div><div>N-Alkylation of 2-methoxy-10H-phenothiazine, a valuable building block for the synthesis of bioactive compounds and reaction-based fluorescent probes, has been revisited aimed at introducing a substituent easily convertible into cationic or zwitterionic side chains. We focused our attention on the 3-dimethylaminopropyl group since its derivatization through reactions with various alkyl halides or sultones is a well-established and effective way to enhance polarity of diverse hydrophobic molecular scaffolds. This two-step functionalization approach was applied to the synthesis of novel phenothiazine-coumarin hybrid dyes whose spectral features, especially their NIR-I emission, have been determined in aqueous media with the ultimate goal of identifying novel fluorescent markers for bioanalytical applications, including fluorogenic detection of reactive oxygen species (ROS) through selective S-oxidation reaction of phenothiazine scaffold. </div><div><br /></div> | Valentin Quesneau; Kevin Renault; Myriam Laly; Sébastien Jenni; Flavien Ponsot; Anthony ROMIEU | Bioorganic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74f11bb8c1a6c653db868/original/n-alkylation-of-2-methoxy-10h-phenothiazine-revisited-a-facile-entry-to-diversely-n-substituted-phenothiazine-coumarin-hybrid-dyes.pdf |
63ec4e5e9da0bc6b33f1ef58 | 10.26434/chemrxiv-2023-zsvnt | Half-substituted fluorocycloparaphenylenes with high symmetry: Synthesis, properties and derivatization to densely substituted carbon nanorings | Cycloparaphenylenes (CPPs) are ring-shaped aromatic hydrocarbons in which benzene rings are connected to each other at the para-positions. In recent years, fluorinated CPPs (FCPPs) have attracted much attention as electron-accepting CPPs as well as strained fluoroarenes. Herein, we report the synthesis, properties, and derivatization of novel FCPPs; F16[8]CPP (1) and F12[6]CPP (2), in which ortho-difluorophenylene units are circularly connected to form CPP structure. The short-step synthesis of 1 and 2 has been achieved by the strategy using macrocyclic nickel or gold complexes. Furthermore, the derivatization of 1 was successfully achieved to afford a new heteroring-containing carbon nanoring; hexadecapyrrolyl[8]cycloparaphenylene 5, where 16 pyrrole rings are densely substituted on CPP framework. | Hiroki Shudo; Motonobu Kuwayama; Yasutomo Segawa; Akiko Yagi; Kenichiro Itami | Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2023-02-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63ec4e5e9da0bc6b33f1ef58/original/half-substituted-fluorocycloparaphenylenes-with-high-symmetry-synthesis-properties-and-derivatization-to-densely-substituted-carbon-nanorings.pdf |
64a8a2f46e1c4c986b015590 | 10.26434/chemrxiv-2023-mbznv | Deaminative ring contraction for the synthesis of polycyclic heteroaromatics: a concise total synthesis of toddaquinoline | A concise strategy to prepare polycyclic heteroaromatics involving a deaminative contraction cascade is detailed. The efficient deaminative ring contraction involves the in situ methylation of a biaryl-linked dihydroazepine to form a cyclic ammonium cation that undergoes a base-induced [1,2]-Stevens rearrangement/dehydroamination sequence. The presence of pseudosymmetry guides the retrosynthetic analysis of pyridyl-containing polycyclic heteroaromatics, enabling their construction by the reductive cyclization and deaminative contraction of tertiary amine precursors. | Emily Kirkeby; Zachary Schwartz; Myles Lovasz; Andrew Roberts | Organic Chemistry; Natural Products; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64a8a2f46e1c4c986b015590/original/deaminative-ring-contraction-for-the-synthesis-of-polycyclic-heteroaromatics-a-concise-total-synthesis-of-toddaquinoline.pdf |
64f10403dd1a73847fe9878b | 10.26434/chemrxiv-2023-7dc4s | Multiple Verdazyl Radicals Appended to a Triarylamine Scaffold | We report the synthesis of three triphenylamine-based verdazyl radicals. These include a mono, bis, and tris(verdazyl) at the 4-position(s) of the N–Ar groups, containing one, two, and three unpaired electrons, respectively. Each of these compounds is air stable, and fully characterized using EPR spectroscopy, high-resolution mass spectrometry, infrared spectroscopy, UV/Vis spectroscopy, and cyclic voltammetry. From the UV/Vis absorbance data, the optical absorbance energy gaps were found to be ~2.35 eV for all three verdazyl-containing compounds. Cyclic voltammetry was used to estimate the energy levels of the singly occupied molecular orbitals (SOMOs), which are -4.91 eV, -5.12 eV, and -4.98 eV for mono, bis, and tris(verdazyl) compounds respectively. Spin-spin exchange interactions were observed in the EPR spectra of both the bis and tris(verdazyl)s, leading to additional hyperfine coupling patterns and assignment of the ground states as triplet and quartet, respectively. | Sydney Reiber; Bennett Templeman-Vivian; Michelle Mills; Christopher Tremblay; David Leitch; Erin Chernick | Organic Chemistry; Organic Compounds and Functional Groups; Physical Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64f10403dd1a73847fe9878b/original/multiple-verdazyl-radicals-appended-to-a-triarylamine-scaffold.pdf |
60c73edbf96a00f486285fd6 | 10.26434/chemrxiv.7159733.v1 | Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability | Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources
for microbe proliferation. Smart photocatalytic coatings on building surfaces
using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this
growing threat.<b> </b>Metal-doped
titania in anatase phase has been proved as a promising candidate for energy
and environmental applications. In this present work, the antimicrobial
efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was
evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus
aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute
fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub>
further calcined at various temperatures
(in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub>
anatase phase. The physico-chemical properties of the samples were
characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray
photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD
results revealed that the anatase phase of TiO<sub>2</sub> was maintained well,
up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light
absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is
reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the
introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup>
ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further
promoted the photocatalytic efficiency. A significantly high bacterial
inactivation (99.9%) was attained in 30 mins of visible light irradiation by
Cu-TiO<sub>2</sub>. | Snehamol Mathew; Priyanka Ganguly; Stephen Rhatigan; Vignesh Kumaravel; Ciara Byrne; Steven Hinder; John Bartlett; Michael Nolan; Suresh Pillai | Minerals; Computational Chemistry and Modeling; Theory - Computational; Photocatalysis; Physical and Chemical Properties | CC BY NC ND 4.0 | CHEMRXIV | 2018-10-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73edbf96a00f486285fd6/original/cu-doped-ti-o2-visible-light-assisted-photocatalytic-antimicrobial-activity-and-high-temperature-anatase-stability.pdf |
60c74b2dbb8c1a335e3db160 | 10.26434/chemrxiv.12302018.v1 | Nonlinear Spectroscopy in the Condensed Phase: The Role of Duschinsky Rotations and Third Order Cumulant Contributions | First-principles modeling of nonlinear optical spectra in the condensed phase is highly challenging because both environment and vibronic interactions can play a large role in determining spectral shapes and excited state dynamics. Here, we compute two dimensional electronic spectroscopy (2DES) signals based on a cumulant expansion of the energy gap fluctuation operator, with a specific focus on analyzing mode mixing effects introduced by the Duschinsky rotation and the role of the third order term in the cumulant expansion for both model and realistic condensed phase systems. We show that for a harmonic model system, the third order cumulant correction captures effects introduced by a mismatch in curvatures of ground and excited state potential energy surfaces, as well as effects of mode mixing. We also demonstrate that 2DES signals can be accurately reconstructed from purely classical correlation functions using quantum correction factors. We then compute nonlinear optical spectra for the Nile red and Methylene blue chromophores in solution, assessing the third order cumulant contribution for realistic systems. We show that the third order cumulant correction is strongly dependent on the treatment of the solvent environment, revealing the interplay between environmental polarization and the electronic-vibrational coupling. | Tim Zuehlsdorff; Hanbo Hong; Liang Shi; Christine Isborn | Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74b2dbb8c1a335e3db160/original/nonlinear-spectroscopy-in-the-condensed-phase-the-role-of-duschinsky-rotations-and-third-order-cumulant-contributions.pdf |
6539c5f6a8b423585a396edf | 10.26434/chemrxiv-2023-7trfj | An electrochemical approach to aluminum-based redox switchable ring opening polymerization | We report the electrochemically switchable reactivity of (salfen)Al(OiPr) (salfen = 1,1′-di(2,4-bis-tert-butyl-salicylimino)ferrocene) toward the ring opening polymerization of various cyclic esters, ethers, and carbonates. Using a recently developed electrochemical system comprised of an H-cell and glassy carbon working electrode, an applied potential can alternate between two redox states of the catalyst and alter monomer incorporation during ring opening polymerization. We discuss differences in activity and control under electrochemical conditions compared to previously studied chemical redox methods and discuss the necessity of a redox switch during certain copolymerization reactions. | Zachary Hern; Amy Lai; Ramzi Massad; Paula Diaconescu | Catalysis; Organometallic Chemistry; Polymer Science; Redox Catalysis; Electrochemistry - Organometallic | CC BY NC ND 4.0 | CHEMRXIV | 2023-10-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6539c5f6a8b423585a396edf/original/an-electrochemical-approach-to-aluminum-based-redox-switchable-ring-opening-polymerization.pdf |
60c7526f469df4757ff44b68 | 10.26434/chemrxiv.13296524.v1 | Molecular Docking and Clinical Study of Inhibition of Phytochemical Compounds of Nigella Sativa, Matricaria Chamomilla and Origanum Vulgare L on COVID_19 Mpro | <p>Due to the high rate of infection
reported in the new Coronavirus, in recent months, a lot of research has been
done on the introduction of antiviral drugs. Recent studies have shown that
inhibiting viral protease enzymes are highly effective in controlling infection
caused by any type of virus. The aim of this study was to investigate the
bioinformatics of inhibition of the new coronavirus protease enzyme by
compounds in the essential oils of three medicinal plants. This is a
descriptive-analytical study. For this bioinformatics analysis, the structure
of compounds from PubChem database and the structure of COVID_19 protease
enzyme were obtained from PDB database. Molecular docking was then performed by
MVD software. The results showed that the site of interaction of the compounds
in the protected area is enzymatic flap. Also, 15 patients voluntarily received
steam therapy with the essential oils of these plants and their symptoms of
lung infection improved. Therefore, it can be concluded that the studied
compounds with strong interaction due to their natural origin and the
possibility of less side effects, as well as their direct entry into the
respiratory tract, these compounds are suitable for drug treatment for
coronavirus infection.</p> | Neda Shaghaghi; Sima Fereydooni; Naiemeh Molaei kordabad | Bioinformatics and Computational Biology; Drug Discovery and Drug Delivery Systems; Plant Biology | CC BY NC ND 4.0 | CHEMRXIV | 2020-12-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7526f469df4757ff44b68/original/molecular-docking-and-clinical-study-of-inhibition-of-phytochemical-compounds-of-nigella-sativa-matricaria-chamomilla-and-origanum-vulgare-l-on-covid-19-mpro.pdf |
60c757a3567dfe5240ec66dc | 10.26434/chemrxiv.14442290.v1 | Site-Selective A-C-H Functionalization of Trialkylamines via Reversible Hydrogen Atom Transfer Catalysis | Trialkylamines are widely found in naturally-occurring alkaloids, synthetic agrochemicals, biological
probes, and especially pharmaceuticals agents and pre-clinical candidates. Despite the recent
breakthrough of catalytic alkylation of dialkylamines, the selective a-C(sp3
)–H bond functionalization of
widely available trialkylamine scaffolds holds promise to streamline complex trialkylamine synthesis,
accelerate drug discovery and execute late-stage pharmaceutical modification with complementary
reactivity. However, the canonical methods always result in functionalization at the less-crowded site.
Herein, we describe a solution to switch the reaction site through fundamentally overcoming the steric
control that dominates such processes. By rapidly establishing an equilibrium between a-amino C(sp3
)-H
bonds and a highly electrophilic thiol radical via reversible hydrogen atom transfer, we leverage a slower
radical-trapping step with electron-deficient olefins to selectively forge a C(sp3
)-C(sp3
) bond with the
more-crowded a-amino radical, with the overall selectivity guided by Curtin-Hammett principle. This subtle
reaction profile has unlocked a new strategic concept in direct C-H functionalization arena for forging C–
C bonds from a diverse set of trialkylamines with high levels of site-selectivity and preparative utility.
Simple correlation of site-selectivity and 13C NMR shift serves as a qualitative predictive guide. The broad
consequences of this dynamic system, together with the ability to forge N-substituted quaternary carbon
centers and implement late-stage functionalization techniques, holds tremendous potential to streamline
complex trialkylamine synthesis and accelerate drug discovery | Yangyang Shen; Franziska Schoenebeck; Ignacio Funes-Ardoiz; Tomislav Rovis | Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c757a3567dfe5240ec66dc/original/site-selective-a-c-h-functionalization-of-trialkylamines-via-reversible-hydrogen-atom-transfer-catalysis.pdf |
66d02b73a4e53c4876fb197f | 10.26434/chemrxiv-2024-l063v-v2 | Health Implications of Hydraulic Fracturing of Water | Hydraulic fracturing is becoming an increasingly prevalent part of today's society, for natural gas fuels energy industries. The contaminants used in fracturing fluid pose a threat to human health. These contaminants can be categorized into volatile organic compounds, metals, inorganic compounds, dissolved solids, radioactive elements, and microorganisms. This paper presents a review of literature from studies exploring the adverse health effects of the following contaminants: benzene, formaldehyde, arsenic, lead, and microorganisms. By ingesting water near hydraulic fracturing sites, people can develop health complications including cancer, disease, body system dysfunction, and genetic disruption. Consequently, purifying contaminated water is necessary to sustain a healthy life. | Alisha Bhatia | Biological and Medicinal Chemistry; Earth, Space, and Environmental Chemistry; Hydrology and Water Chemistry; Wastes; Cell and Molecular Biology | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d02b73a4e53c4876fb197f/original/health-implications-of-hydraulic-fracturing-of-water.pdf |
641b1750aad2a62ca12bf7b3 | 10.26434/chemrxiv-2023-w8jhh | Dual-Hydrogen-Bond Donor and Brønsted Acid Co-Catalysis Enables Highly Enantioselective Protio-Semipinacol Rearrangement Reactions | A catalytic protio-semipinacol ring-expansion reaction has been developed for the highly enantioselective conversion of ter-tiary vinyl cyclopropanols into cyclobutanone products bearing alpha-quaternary stereogenic centers. The method relies on the co-catalytic effect of a chiral dual-hydrogen-bond donor (HBD) with hydrogen chloride. Experimental and computational evidence is provided for a stepwise mechanism proceeding through an enantiodetermining, HBD-promoted protonation of the alkene to generate a discrete carbocationic intermediate. This short-lived (20 ps), high-energy carbocation is generated in a chiral conformation in the presence of HBD catalyst and undergoes subsequent stereospecific C–C bond migration to the enantioenriched product. This research applies strong acid/chiral HBD co-catalysis to weakly basic olefinic substrates and lays the foundation for further investigations of enantioselective reactions involving high-energy cationic intermediates. | Melanie Blackburn; Corin Wagen; Raul Bodrogean; Pamela Tadross; Andrew Bendelsmith; Dennis Kutateladze; Eric Jacobsen | Theoretical and Computational Chemistry; Organic Chemistry; Catalysis; Physical Organic Chemistry; Acid Catalysis; Organocatalysis | CC BY NC 4.0 | CHEMRXIV | 2023-03-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/641b1750aad2a62ca12bf7b3/original/dual-hydrogen-bond-donor-and-br-nsted-acid-co-catalysis-enables-highly-enantioselective-protio-semipinacol-rearrangement-reactions.pdf |
66993087c9c6a5c07a9c14b5 | 10.26434/chemrxiv-2024-b1rvv-v2 | Regeneration of PFAS-laden Granular Activated Carbon in Modified Supercritical CO2 Extraction | Granular activated carbon (GAC) is widely used to treat contaminated per- and polyfluoroalkyl substances (PFAS) waste streams, resulting in the accumulation of large quantities of spent GAC that need to be landfilled or regenerated. A novel modified supercritical CO2 (scCO2) extraction for regeneration of spent GAC is developed. With the addition of organic solvents and acid modifiers, the procedure yielded > 97% perfluorooctanoic acid (PFOA) desorption after a 60-minute treatment in a continuous flow reactor. The mild extraction conditions at T ~ 100°C do not trigger the formation of volatile organic fluorine or changes in GAC sorbent properties. Mechanistically, the high miscibility of co-solvent/scCO2 eliminates diffusion transport limitations, enabling rapid reagent and PFAS transport in a single-phase (gas-like) medium. The introduction of organic co-solvent and the absence of water reverses hydrophobic interactions between GAC and the PFAS. The acid modifier minimizes the electrostatic PFOA/ GAC interactions by protonating the perfluorooctanoate ion and providing competition for active GAC sites. The approach offers an economically effective regeneration scheme, enabling the reuse of sorbents and yielding effluent with a high loading of PFAS that is amenable to subsequent end-of-life treatment technologies. | Tatiana Didenko; Almond Lau; Anmol L. Purohit; Ji Feng; Brian Pinkard; Mohamed Ateia; Igor V. Novosselov | Physical Chemistry; Earth, Space, and Environmental Chemistry; Chemical Engineering and Industrial Chemistry; Environmental Science; Water Purification; Physical and Chemical Processes | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66993087c9c6a5c07a9c14b5/original/regeneration-of-pfas-laden-granular-activated-carbon-in-modified-supercritical-co2-extraction.pdf |
629a30b2f6869a8bf9f5b803 | 10.26434/chemrxiv-2022-k6c18 | Effect of conformational disorder on exciton states of an azobenzene aggregate
| Azobenzene is a prototypical molecular photoswitch, widely used to trigger a variety of transformations at different length scales. In systems like self-assembled monolayers or micelles azobenzene chromophores may interact with each other, which gives rise to emergence of exciton states. Here, using first-principles calculations, we investigate how conformational disorder (induced, e.g., by thermal fluctuations) affects localization of these states, on an
example of an H-type azobenzene tetramer. We find that conformational disorder leads to (partial) exciton localization on a single-geometry level, whereas ensemble-averaging results in a delocalized picture. The ππ* and nπ* excitons at high and low temperatures are discussed.
| Evgenii Titov | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Physical and Chemical Processes; Quasiparticles and Excitations | CC BY 4.0 | CHEMRXIV | 2022-06-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/629a30b2f6869a8bf9f5b803/original/effect-of-conformational-disorder-on-exciton-states-of-an-azobenzene-aggregate.pdf |
60c7409e9abda26ef2f8bcf9 | 10.26434/chemrxiv.7770368.v1 | A Partially-Planarised Hole-Transporting Quart-p-Phenylene for Perovskite Solar Cells | <div><div><div><p>Herein, we describe the synthesis of a hole transporting material based on a partially planarised quart-p-phenylene core incorporating tetraketal and diphenylamine substituents that show optimal energy levels and solubility for perovskite solar cell applications. Triple-cation perovskite devices incorporating such quart-p-phenylene derivative show power-conversion efficiencies, short circuit currents, open circuit voltages, and fill factors that are comparable to those of spiro-OMeTAD.</p></div></div></div> | Juan P. Mora-Fuentes; Diego Cortizo-Lacalle; Silvia Collavini; Karol Strutyński; Wolfgang R. Tress; Michael Saliba; Shaik M. Zakeeruddin; Ivet Kosta; Manuel Melle-Franco; Michael Grätzel; Juan Luis Delgado; Aurelio Mateo-Alonso | Physical Organic Chemistry; Dyes and Chromophores; Oligomers; Photovoltaics | CC BY NC ND 4.0 | CHEMRXIV | 2019-02-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7409e9abda26ef2f8bcf9/original/a-partially-planarised-hole-transporting-quart-p-phenylene-for-perovskite-solar-cells.pdf |
65a53aa3e9ebbb4db93627d4 | 10.26434/chemrxiv-2024-r1436 | Excitonic Configuration Interaction: Going Beyond the Frenkel Exciton Model | We present the excitonic configuration interaction (ECI) method — a fragment-based analogue of the CI method for electronic-structure calculations of the multichromophoric systems. It can also be viewed as a generalization of the exciton approach which (i) allows embedding via point charges with arbitrary values in the site-state calculation, (ii) includes multi-local excitation (MLE) products of site states in the excitonic basis, in addition to the ground-state (GS) and local excitation (LE) products, and (iii) takes into account all contributions to the full-system Hamiltonian matrix elements within the strong-orthogonality assumption. Regarding (i), we present the excitonic analogue of the Hartree-Fock method — called the EHF approach — which finds the embedding charges that minimize the energy of the GS product. In (ii), one can restrict the excitation rank of the employed excitonic basis, which results in truncated-CI-like expansions (ECIS includes GS and LE products, ECISD additionally includes two-fragment excitation, etc.). The expressions for the matrix elements in (iii) are obtained within McWeeny’s group function theory, generalized to accommodate the flexible embedding in (i).
We assess the performance of ECI by computing absorption spectra of two multichromophoric systems. The first system, a metal-free guanine quadruplex, has the chromophores connected via hydrogen bonds (a supramolecular complex). The second system, a guanine quadruplex with a central Mg-cation, additionally exhibits metal–ligand bonds between some chromophores. It is shown that the accuracy of ECI strongly depends on the chosen embedding charges and ECI expansion. The most accurate combinations — ECIS or ECISD with EHF embedding — yielded spectra that qualitatively and quantitatively agree with full-system direct calculations, with RMSDs of the excitation energies around 20 meV or 100 meV, respectively, for the first and second test system. We also show that ECISD based on CIS site-state calculations can predict states of dominant MLE character that would be inaccessible in a full-system CIS calculation. | Tomislav Piteša; Severin Polonius; Leticia González ; Sebastian Mai | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY 4.0 | CHEMRXIV | 2024-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65a53aa3e9ebbb4db93627d4/original/excitonic-configuration-interaction-going-beyond-the-frenkel-exciton-model.pdf |
659e3c3b66c13817291e5810 | 10.26434/chemrxiv-2024-sns8n | Porous soft materials with liquid-glass-crystal interconvertibility based on metal-organic polyhedra | The capability of materials to interconvert between different phases provides more possibilities for controlling materials’ properties without additional chemical modification. The study of state-changing microporous materials just emerged and mainly involves the liquefication or amorphization of solid adsorbents into liquid or glass phases by adding non-porous components or sacrificing their porosity. The material featuring reversible phases with maintained porosity is, however, yet to be achieved. Here, we synthesize metal-organic polyhedra (MOPs) that interconvert between the liquid-glass-crystal phases. The modular synthetic approach is applied to integrate the core MOP cavity that provides permanent microporosity with tethered polymers that dictate the phase transition. We showcase the processibility of this material by fabricating a gas separation membrane featuring tunable permeability and selectivity by switching the state. The liquid MOP membrane particularly shows a unique selectivity of CO2 over H2 with enhanced permeability, compared to most conventional porous membranes. | Po-Chun Han; Chia-Hui Chuang; Shang-Wei Lin; Zaoming Wang; Mako Kuzumoto; Xiangmei Xiang; Shun Tokuda; Tomoki Tateishi; Alexandre Legrand; Min Ying Tsang; Hsiao-Ching Yang; Kevin C.-W. Wu; Kenji Urayama; Dun-Yen Kang; Shuhei Furukawa | Materials Science; Inorganic Chemistry; Coordination Chemistry (Inorg.); Supramolecular Chemistry (Inorg.); Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2024-01-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/659e3c3b66c13817291e5810/original/porous-soft-materials-with-liquid-glass-crystal-interconvertibility-based-on-metal-organic-polyhedra.pdf |
60c73f46ee301c0600c78874 | 10.26434/chemrxiv.7286243.v1 | A Fast Approximation for Adaptive Wavelength Selection for Infrared Chemical Sensors | <p>Active mid-infrared spectroscopy with tunable lasers is a leading technology for standoff detection and identification of trace chemicals. Information-theoretic optimal selection of the laser wavelength offers the promise of increased detection confidence at lower abundances and with fewer wavelengths. Reducing the number of wavelengths required enables faster detections and lowers sensor power consumption while keeping the optical power under eye safety limits. This paper presents an approximation to the mutual information which operates ~40000x faster than traditional techniques, thereby making near-optimal real-time sensor control computationally feasible. Application of this technique to synthetic data suggests it can reduce the number of wavelengths needed by a factor of two relative to an evenly-spaced grid, with even higher gains for chemicals with weak signatures.</p> | Mark Chilenski; Cara Murphy; Gil Raz | Imaging; Spectroscopy (Anal. Chem.); Chemoinformatics - Computational Chemistry; Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2018-11-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73f46ee301c0600c78874/original/a-fast-approximation-for-adaptive-wavelength-selection-for-infrared-chemical-sensors.pdf |
63d1b5fdfa87ebd0aa54d1eb | 10.26434/chemrxiv-2023-bjpp8 | Inducing Exraordinarily Piezoelectric Response via Homogeneous and Heterogeneous
Functionalization of a Sc2C Nanosheet, A Quantum Chemical Investigation | Piezoelectricity is pivotal for applications in micro/nanoelectromechanical (MEMS/NEMS) systems.
Inducing such property into the two-dimensional Sc2CTT′ MXenes (where T and T′ are the functionalization
atoms) via homogeneous and heterogeneous surface functionalization is explored. The
functionalization atoms T and T′ located at the upper and lower surfaces, respectively, are identical
in the case of homogeneous functionalization, while they differ in the case of heterogeneous functionalization.
Upon T and T′ exchange, an additional reverse heterogeneous configuration is generated.
The heterogeneous functionalization of Sc2CT2 induces an extraordinary in-plane and out-of-plane
piezoelectric effect owing to symmetry breaking. Interestingly, both heterogeneous and its reverse
configuration show approximately identical geometrical, energetic, and even elastic properties, but
rather different piezoelectric coefficients. The obtained piezoelectric effect is more than ten times
larger than the experimentally measured piezoelectricity of MoS2-monolayer. Our study suggests a
way toward more efficient nanoscale piezoelectric devices based on Sc2C MXenes. | Khaled El-Kelany; Safwat Abdel-Azeim; Oliver Kuehn; Ahmed El-Zatahry; Mohamed Shibl | Theoretical and Computational Chemistry; Theory - Computational; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-01-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63d1b5fdfa87ebd0aa54d1eb/original/inducing-exraordinarily-piezoelectric-response-via-homogeneous-and-heterogeneous-functionalization-of-a-sc2c-nanosheet-a-quantum-chemical-investigation.pdf |
60d88358461f569231490677 | 10.26434/chemrxiv-2021-rrmw2-v2 | A Convenient Synthesis of Thiol, Trithiocarbonate and Disulfide | <div>Synthesis of unsymmetrical trithiocarbonate sulfonate salt, along with disulfide, thiol and</div><div>symmetrical trithiocarbonate from 3-mercapto-1-propane-sulfonicacid, sodium salt with, without</div><div>of phase transfer catalyst and under various reaction conditions are described. The obtained</div><div>compounds having divergent usefulness in RAFT polymerization, sulfonyl preparation and</div><div>having capable of binding in a multidentate fashion to soft transition metal ions.</div> | Sudershan Reddy Gondi; Christiana Julia Rissing; DAVID SON | Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY 4.0 | CHEMRXIV | 2021-06-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60d88358461f569231490677/original/a-convenient-synthesis-of-thiol-trithiocarbonate-and-disulfide.pdf |
60c749e9337d6ccc51e277ba | 10.26434/chemrxiv.12130872.v1 | Ab Initio Molecular Dynamics Reveals New Active Sites in Atomically Dispersed Pt1/TiO2 Catalysts | <div>
<div>
<div>
<p>We present a multi-scale modeling study of atomically dispersed Pt on the (110)
surface of rutile TiO2. Using density functional theory (DFT) and ab initio molecular
dynamics (AIMD), we probe the dynamic evolution of the catalytic surface at elevated
temperatures. We identify metal atom diffusion as well as support atom mobility as
important dynamical phenomena that enable the formation of new active sites. Among
the eight new dynamically formed sites that are distinct from prior experimental and
DFT reports, two sites exhibit anionic, near-linear O−Pt−O configurations. Such
configurations are neither intuitive nor easily located using static methods such as DFT.
Therefore, DFT alone is not sufficient to obtain a complete, dynamic description of
the catalytic surface. Furthermore, the near-linear O−Pt−O sites exhibit CO binding
characteristics that are markedly distinct from their parent sites, with possibly higher
activity towards CO oxidation and water-gas shift reactions. Based on the wide range
of adsorbate affinities exhibited by the DFT and AIMD-generated sites in this study,
our aim going forward is to probe site-sensitivity of water-gas shift kinetics with these
catalysts.
</p>
</div>
</div>
</div> | Nicholas Humphrey; Selin Bac; Shaama Mallikarjun Sharada | Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c749e9337d6ccc51e277ba/original/ab-initio-molecular-dynamics-reveals-new-active-sites-in-atomically-dispersed-pt1-ti-o2-catalysts.pdf |
6537e56f87198ede072cfffb | 10.26434/chemrxiv-2023-dr67s | Spontaneous Symmetry Breaking of Achiral Molecules Leading to the Formation of Homochiral Superstructures that Exhibit Mechanoluminescence | Chirality, with its intrinsic symmetry-breaking feature, is frequently utilized in the creation of acentric crystalline functional materials that exhibit intriguing optoelectronic properties. On the other hand, the development of chiral crystals from achiral molecules offers a solution that bypasses the need for enantiopure motifs, presenting a promising alternative and thereby expanding the possibilities of the self-assembly toolkit. Nevertheless, the rational design of achiral molecules that prefer spontaneous symmetry breaking during crystallization has so far been obscure. In this study, we present a series of six achiral molecules, demonstrating that when these conformationally flexible molecules adopt a cis-conformation and engage in multiple non-covalent interactions along a helical path, they collectively self-assemble into chiral superstructures consisting of single-handed supramolecular columns. When these homochiral supramolecular columns align in parallel, they form polar crystals that exhibit intense luminescence upon grinding or scraping. We therefore demonstrate our molecular design strategy could significantly increase the likelihood of symmetry breaking in achiral molecular synthons during self-assembly, offering a facile access to novel chiral crystalline materials with unique optoelectronic properties. | Zheng-Fei Liu; Xin-Yi Ye; Lihua Chen; Li-Ya Niu; Wei Jun Jin ; Shaodong Zhang ; Qing-Zheng Yang | Physical Chemistry; Organic Chemistry; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-10-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6537e56f87198ede072cfffb/original/spontaneous-symmetry-breaking-of-achiral-molecules-leading-to-the-formation-of-homochiral-superstructures-that-exhibit-mechanoluminescence.pdf |
661d52d591aefa6ce19d3886 | 10.26434/chemrxiv-2024-0pcrj | 3D Printing Carbon-Carbon Composites With Multilayered
Architecture for Enhanced Multifunctional
Properties | Carbon-carbon (C-C) composites are highly sought-after in aviation, automotive, and defense sectors
due to their outstanding thermal and thermo-mechanical properties. These composites are highly
valued for their exceptional thermal and thermo-mechanical properties, including remarkably low
density and coefficient of thermal expansion, which are expected to surpass those of many alloys and
other composites in the production of high-grade components. However, the current manufacturing
methods for C-C composites are unable to meet market demands due to their high cost, low production
speed, and labor-intensive processes, limiting their broader applications. This study presents
an innovative approach by introducing a new extrusion-based 3D printing method using multiphase
direct ink writing (MDIW) for C-C composite fabrication. The primary matrix utilized is a phenolformaldehyde
thermosetting resin, reinforced with silicon carbide (SiC) and graphite nanopowder
(Gnp), focusing on achieving simple, scalable, and environmentally sustainable production of green
parts with enhanced polymer matrix. This is followed by an inert carbonization process to obtain the
final C-C composites. The research emphasizes the careful optimization of curing and rheological
properties, including the use of suitable viscosity modifiers like carbon black (CB). Furthermore,
the MDIW process demonstrates its capability to pattern dual nanoparticles within the composite
structure in a well-ordered manner, leading to improved overall performance. Thermo-mechanical
and thermo-electrical properties were thoroughly tested, showcasing the multifunctionality of the
composite for diverse applications, from high-value industries like aerospace to broader uses such as
heatsinks and electronic packaging. | Dharneedar Ravichandran; Anna Dmochowska; Barath Sundaravadivelan; Varunkumar Thippanna; Emile Motta de Castro; Dhanush Patil; Arunachalam Ramanathan; Yuxiang Zhu; Amir Asadi; Jorge Peixinho; Guillaume Miquelard-Garnier; Kenan Song | Materials Science; Polymer Science; Carbon-based Materials; Composites; Multilayers | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/661d52d591aefa6ce19d3886/original/3d-printing-carbon-carbon-composites-with-multilayered-architecture-for-enhanced-multifunctional-properties.pdf |
671123ff51558a15ef59f01a | 10.26434/chemrxiv-2024-nh0xn | Autonomous Discovery of Functional Random Heteropolymer Blends through Evolutionary Formulation Optimization | While developing new polymers typically requires years of investigation, blending existing polymers offers a cost-effective strategy for creating new materials that meet specific requirements. Yet identifying functional polymer blends is often a laborious development process, complicated by the vast design space and non-additive nature of polymer properties, exacerbated by an often-limited understanding of structure-function relationships. To this end, we report an autonomous closed-loop platform with an evolutionary algorithm for the development of functional polymer blends. We focus on random heteropolymers (RHPs), which are gathering increasing interest as versatile materials with a range of promising applications. Using enzyme thermal stabilization as an objective, we identify blended compositions from combinatorial 96- or 192-dimensional spaces (with over 10^9 potential candidates) that exhibit emergent function and outperform all of their constituent polymers by an absolute margin of 26% retained enzyme activity. Our findings highlight the immense potential of leveraging autonomous closed-loop discovery platforms for polymer blend discovery, as well as the opportunity for materials discovery within the RHP blend space. The algorithmic goal of blend optimization also bears a strong resemblance to other formulation optimization problems that are pervasive in molecular and material discovery. | Guangqi Wu; Tianyi Jin; Alfredo Alexander-Katz; Connor Coley | Polymer Science; Chemical Engineering and Industrial Chemistry; Organic Polymers; Polymer blends | CC BY NC ND 4.0 | CHEMRXIV | 2024-10-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/671123ff51558a15ef59f01a/original/autonomous-discovery-of-functional-random-heteropolymer-blends-through-evolutionary-formulation-optimization.pdf |
60c74da6bb8c1a4ffa3db620 | 10.26434/chemrxiv.12644153.v1 | General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors | The addition of organometallic reagents to ketones constitutes one of the most straightforward synthetic approaches to tertiary
alcohols. However, due to the absence of a well-behaved class of cyclopropanone surrogates accessible in enantioenriched form, such a trivial
synthetic disconnection has only received very little attention in the literature for the formation of tertiary cyclopropanols. In this work, we
report a simple and high-yielding synthesis 1-substituted cyclopropanols via the addition of diverse organometallic reagents to 1-
phenylsulfonylcyclopropanols, acting here as in situ precursors of the corresponding cyclopropanones.The transformation is shown to be amenable to sp, sp2 or sp3
-hybridized organometallic C-nucleophiles under mild conditions, and the use of enantioenriched substrates led to highly
diastereoselective additions and the formation of optically active cyclopropanols. | Roger Machín Rivera; Yujin Jang; Christopher M. Poteat; Vincent Lindsay | Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2020-07-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74da6bb8c1a4ffa3db620/original/general-synthesis-of-cyclopropanols-via-organometallic-addition-to-1-sulfonylcyclopropanols-as-cyclopropanone-precursors.pdf |
62a7774bb749a0a55da24b15 | 10.26434/chemrxiv-2022-zx0bq-v2 | Paramagnetic NMR Shielding Tensors Based on Scalar Exact Two-Component and Spin-Orbit Perturbation Theory | The temperature-dependent Fermi-contact and pseudocontact terms are important contributions to the paramagnetic NMR shielding tensor. Herein, we augment the scalar-relativistic (local) exact two-component (X2C) framework with spin-orbit perturbation theory including the screened nuclear spin-orbit correction for the EPR hyperfine coupling and g tensor to compute these temperature-dependent terms. The accuracy of this perturbative ansatz is assessed with the self-consistent spin-orbit two-component and four-component treatments serving as reference. This shows that the Fermi-contact and pseudocontact interaction is sufficiently described for paramagnetic NMR shifts, however, larger deviations are found for the EPR spectra and the principle components of the EPR properties of heavy elements. The impact of the perturbative treatment is further compared to that of the density functional approximation and the basis set. Large scale calculations are routinely possible with the multipole accelerated resolution of the identity approximation and the seminumerical exchange approximation as shown for [CeTi6O3(OiPr)9(salicylate)6]. | Florian Bruder; Yannick J. Franzke; Florian Weigend | Theoretical and Computational Chemistry; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2022-06-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62a7774bb749a0a55da24b15/original/paramagnetic-nmr-shielding-tensors-based-on-scalar-exact-two-component-and-spin-orbit-perturbation-theory.pdf |
62e20066adb01e1424af43a1 | 10.26434/chemrxiv-2022-x8kdv | PEDOT-NHS as a Versatile Conjugated Polyelectrolyte for Bioelectronics | The field of bioelectronics leverages the optoelectronic properties of synthetic materials to interface with living systems. These applications require materials that are conductive, aqueous processible, biocompatible, and can be chemically modified for biofunctionalization. While conjugated polymers and polyelectrolytes have been reported that demonstrate several of these features, materials that offer each of these properties simultaneously are rare. Here, we developed copolymers of anionic polyelectrolyte poly(4-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-butane-1-sulfonic acid sodium salt (PEDOT-S), containing structural units with amine-reactive NHS-esters. The reported PEDOT-NHS copolymers demonstrate water-solubility and electrical conductivities similar to previously reported PEDOT-S, as well as the ability to bind important amine-rich biomaterials. Furthermore, the PEDOT-NHS copolymers were biocompatible and hemocompatible, and therefore show promise for next-generation bioelectronic and regenerative engineering applications. | Joshua Tropp; Abijeet Mehta; Ruiheng Wu; Manideep Reddy; Shiv Patel; Anthony Petty; Jonathan Rivnay | Organic Chemistry; Materials Science; Polymer Science; Biocompatible Materials; Conducting polymers; Polyelectrolytes - Polymers | CC BY NC 4.0 | CHEMRXIV | 2022-07-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62e20066adb01e1424af43a1/original/pedot-nhs-as-a-versatile-conjugated-polyelectrolyte-for-bioelectronics.pdf |
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