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63e5cdc3fcfb27a31f82237a | 10.26434/chemrxiv-2023-3vrqj | Development of a chemogenetic approach to manipulate
intracellular pH | Chemogenetic Operation of iNTRacellular prOton Levels (pH-Control) is a novel substrate-based enzymatic method that enables precise spatio-temporal control of ultra-local acidification in cultured cell lines and primary neurons. The genetically encoded biosensor SypHer3s showed that pH-Control effectively acidifies cytosolic, mitochondrial, and nuclear pH exclusively in the presence of beta-Chloro-D-alanine in living cells in a concentra-tion-dependent manner. The pH-Control approach is promising for investigating the ultra-local pH imbalance associated with many diseases. | Asal Ghaffari Zaki; Seyed Mohammad Miri; Tuba Akgül Çağlar; Esra Nur Yiğit; Mehmet Şerif Aydın; Gürkan Öztürk; Emrah Eroglu | Biological and Medicinal Chemistry; Biochemistry; Cell and Molecular Biology; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2023-02-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63e5cdc3fcfb27a31f82237a/original/development-of-a-chemogenetic-approach-to-manipulate-intracellular-p-h.pdf |
65b0e13fe9ebbb4db9de37ef | 10.26434/chemrxiv-2023-5455b-v2 | Intracellular delivery of functional proteins with DNA-protein nanogels-lipids complex | Using functional proteins for therapeutic purposes due to their high selectivity and/or catalytic properties can enable the control of various cellular processes, however, the transport of active proteins inside living cells remains a major challenge. In contrast, intracellular delivery of nucleic acids has become a routine method for a number of applications in gene therapy, genome-editing or immunization. Here we report a functionalizable platform constituting of DNA-protein nanogel carriers crosslinked through streptavidin-biotin or streptactin-biotin interactions and demonstrate its applicability for intracellular delivery of active proteins. We show that the nanogels can be loaded with active proteins bearing either biotin, streptavidin or strep-tag, and the resulting functionalized nanogels can be delivered into living cells after complexation with cationic lipid vectors. We use this approach for delivery of alkaline phosphatase enzyme which is shown to keep its catalytic activity after internalization by mouse melanoma B16 cells, as demonstrated by DDAO-phosphate assay. The resulting functionalized nanogels have dimensions of the order of 100 nm, contain around 100 enzyme molecules and are shown to be transfectable at low lipid concentrations (charge ratio R+/- = 0.75). This ensures low toxicity of our system, which in combination with high local enzyme concentration (~ 100 µM) underlines potential interest of this nanoplatform for biomedical applications. | Marina Mariconti; Laurie Dechamboux; Marion Heckmann; Julien Gros; Mathieu Morel; Virginie Escriou; Damien Baigl; Céline Hoffmann; Sergii Rudiuk | Biological and Medicinal Chemistry; Nanoscience | CC BY 4.0 | CHEMRXIV | 2024-01-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65b0e13fe9ebbb4db9de37ef/original/intracellular-delivery-of-functional-proteins-with-dna-protein-nanogels-lipids-complex.pdf |
625aa2ed368ab67f248168f4 | 10.26434/chemrxiv-2022-5xt71 | A Data-Science Approach to Predict the Heat Capacity of Nanoporous Materials | The heat capacity of a material is a fundamental property that is of significant practical importance. For example, in a carbon capture process, the heat required to regenerate a solid sorbent is directly related to the heat capacity of the material. However, for most materials suitable for carbon capture applications the heat capacity is not known, and thus the standard procedure is to assume the same value for all materials. In this work, we developed a machine-learning approach to accurately predict the heat capacity of these materials, i.e., zeolites, metal-organic frameworks, and covalent-organic frameworks. The accuracy of our prediction is confirmed with novel experimental data. Finally, for a temperature swing adsorption process that captures carbon from the flue gas of a coal-fired power plant, we show that for some materials the heat requirement is reduced by as much as a factor of two using the correct heat capacity. | Seyed Mohamad Moosavi; Balázs Álmos Novotny; Daniele Ongari; Elias Moubarak; Mehrdad Asgari; Özge Kadioglu; Charithea Charalambous; Andres Guerrero; Amir H. Farmahini; Lev Sarkisov; Susana Garcia; Frank Noé; Berend Smit | Theoretical and Computational Chemistry; Chemical Engineering and Industrial Chemistry; Theory - Computational; Machine Learning; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-04-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/625aa2ed368ab67f248168f4/original/a-data-science-approach-to-predict-the-heat-capacity-of-nanoporous-materials.pdf |
648e1e74be16ad5c5713e605 | 10.26434/chemrxiv-2023-00c51 | Formation of carbon-induced nitrogen-centered radicals on titanium dioxide under illumination | Titanium dioxide is the most studied photocatalytic material and has been reported to be active for a wide range of reactions including oxidation of hydrocarbons and reduction of nitrogen. However, the molecular-scale interactions between the titania photocatalyst and dinitrogen are still debated, particularly in the presence of hydrocarbons. Here, we used several spectroscopic and computational techniques to identify interactions between nitrogen, methanol, and titania under illumination. Electron paramagnetic resonance spectroscopy (EPR) allowed us to observe the formation of carbon radicals upon exposure to ultraviolet radiation. These carbon radicals are observed to transform into diazo- and nitrogen-centered radicals (e.g., CHxN2* and CHxNHy*) during photocatalysis in nitrogen. In situ infrared (IR) spectroscopy under the same conditions revealed C-N stretching on titania. Furthermore, density functional theory (DFT) calculations reveal that nitrogen adsorption and the thermodynamic barrier to photocatalytic nitrogen fixation are significantly more favorable in the presence of methanol or surface carbon. These results provide compelling evidence that carbon radicals formed from the oxidation of hydrocarbons interact with dinitrogen, and suggest that the role of carbon-based ``hole scavengers'' and the inertness of nitrogen atmospheres should be reevaluated in the field of photocatalysis. | Po-Wei Huang; Nianhan Tian; Tijana Rajh; Yu-Hsuan Liu; Giada Innocenti; Carsten Sievers; Andrew Medford; Marta Hatzell | Catalysis; Photocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/648e1e74be16ad5c5713e605/original/formation-of-carbon-induced-nitrogen-centered-radicals-on-titanium-dioxide-under-illumination.pdf |
60c7453cbb8c1acb303da650 | 10.26434/chemrxiv.9199634.v2 | A Solvent Free Synthetic Route for Cerium(IV) Metal-Organic Frame-works with UiO-66 Architecture and Their Photocatalytic Application | <div>
<p>A novel solvent-free synthesis for
Ce-UiO-66 metal-organic frameworks (MOFs) is presented. The MOFs are obtained
by simply grinding the reagents, cerium ammonium nitrate (CAN) and the
carboxylic linkers, in a mortar for few minutes with the addition of a small
amount of acetic acid (AcOH) as modulator (1.75 eq, o.1 ml). The slurry is then
transferred into a 1 ml vial and heated at 120°C for 1 day. The MOFs have been
characterized for their composition, crystallinity and porosity and employed as
heterogenous catalysts for the photo-oxidation reaction of substituted benzylic
alcohols to benzaldaldehydes under near ultraviolet light irradiation. The
catalytic performances, such as yield, conversion and kinetics, exceed those of
similar systems studied by chemical oxidation and using Ce-MOF as catalyst.
Moreover, the MOFs were found to be reusable up to three cycles without loss of
activity. Density functional theory (DFT) calculations gave an estimation of
the band-gap shift due to the different nature of the linkers used and provide
useful information on the catalytic activity experimentally observed.</p>
</div> | Matteo Campanelli; Tiziana Del Giacco; Filippo De Angelis; Edoardo Mosconi; Marco Taddei; Fabio Marmottini; Ferdinando Costantino | Coordination Chemistry (Inorg.); Photocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2019-10-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7453cbb8c1acb303da650/original/a-solvent-free-synthetic-route-for-cerium-iv-metal-organic-frame-works-with-ui-o-66-architecture-and-their-photocatalytic-application.pdf |
60c74bde9abda2729df8d17b | 10.26434/chemrxiv.12386126.v1 | Boosting Fast and Stable Potassium-ion Storage by Synergistic Interlayer and Pore-structure Engineering | <p>Carbon-based material has
been regarded as one of the most promising electrode materials for Potassium-ion
batteries (PIBs). However, the battery performance based on reported porous
carbon electrodes is still unsatisfactory, while the in-depth K-ion storage
mechanism remains relatively ambiguous. Herein, we propose a facile “<i>in situ</i>
template bubbling” method for synthesizing interlayer tuned hierarchically
porous carbon with different metallic ions, which delivers superior K-ion
storage performance, especially the rate capability (158.6 mAh g<sup>-1</sup>@10.0
A g<sup>-1</sup>) and high-rate cycling stability (82.8% capacity retention
after 2000 cycles at 5.0 A g<sup>-1</sup>). The origin of the excellent rate
performance is revealed by the deliberately designed consecutive CV
measurements, <i>Ex situ</i> Raman tests, GITT and theoretical simulations. Considering
the facile preparation strategy, superior electrochemical performance and insightful
mechanism investigations, this work can provide fundamental understandings for high
performance PIBs and related energy storage devices like sodium-ion batteries,
aluminum-ion batteries, electrochemical capacitors and dual-ion batteries.</p> | Deping Li; Qing Sun; Yamin Zhang; Xinyue Dai; Fengjun Ji; kaikai Li; Qunhui Yuan; Xingjun Liu; Lijie Ci | Carbon-based Materials | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74bde9abda2729df8d17b/original/boosting-fast-and-stable-potassium-ion-storage-by-synergistic-interlayer-and-pore-structure-engineering.pdf |
66ccd4eb20ac769e5fe9e642 | 10.26434/chemrxiv-2024-n2ktf | Understanding the Formation of Colloidal Ferrimagnetic CuCr2Se4 Nanocrystals with Strong Room-Temperature Magnetic Circular Dichroism | The ongoing development and eventual implementation of magnetic nanocrystals in devices requires not only syntheses that can bring bulk compositions down to the nanoscale but also a deep understanding of their formation such that size, morphology, and composition can be finely tuned. Chromium chalcogenide spinels are a class of materials that epitomize this dilemma; their unique magnetic and magneto-optical properties make them promising for applications in spintronics, data storage, and quantum information sciences, but only a few compositions have been synthesized as colloidal nanocrystals. Furthermore, these few existing reports lack mechanistic understanding and demonstrate little control over the physical characteristics of the final products. Here, we set forth to understand the synthesis of CuCr2Se4 nanocrystals by examining how the structure, composition, and magnetic properties evolve over the course of the reaction. We find that the material proceeds through binary copper selenide nanocrystal intermediates followed by Cr incorporation via diffusion. This process results in polycrystalline CuCr2Se4 nanocrystals that do not exhibit magnetic ordering until Cu incorporation modifies their stoichiometry and defects are annealed, which takes approximately forty minutes at 340 °C to achieve. The resulting CuCr2Se4 nanocrystals show a strongly enhanced magnetic circular dichroism signal at the bulk plasma frequency of ℏω_pl ~ 1.0 eV with a field dependence that reflects magnetization of the Cr3+ spin sublattice. These results highlight the possibility of solution processing strong near-IR magneto-optical materials for future device integration. | Samantha Harvey; Jonathan DeStefano; Jiun-Haw Chiu; Daniel Gamelin; Brandi Cossairt | Materials Science; Nanoscience; Magnetic Materials; Nanostructured Materials - Nanoscience | CC BY NC 4.0 | CHEMRXIV | 2024-08-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66ccd4eb20ac769e5fe9e642/original/understanding-the-formation-of-colloidal-ferrimagnetic-cu-cr2se4-nanocrystals-with-strong-room-temperature-magnetic-circular-dichroism.pdf |
60c7591e469df41c20f457f0 | 10.26434/chemrxiv.14650326.v1 | Investigating Tunneling Controlled Chemical Reactions Through Ab-Initio Ring Polymer Molecular Dynamics | <div>We use the ab-initio ring polymer molecular dynamics (RPMD) approach to investigate tunneling controlled reactions in methylhydroxycarbene. Nuclear tunneling effects enable molecules to overcome the barriers which can not be overcome classically. Under low-temperature conditions, intrinsic quantum tunneling effects canfacilitate the chemical reaction in a pathway that is neither favored thermodynamically nor kinetically. This</div><div>behavior is referred to as the tunneling controlled chemical reaction and regarded as the third paradigm of chemical</div><div>reaction controls. In this work, we use the ab-initio RPMD approach to incorporate the tunneling effects in our quantum dynamics simulations. The reaction kinetics of two competitive reaction pathways at various temperatures are investigated with the Kohn-Sham density functional theory (KS-DFT) on-the-fly molecular dynamics simulations and the ring polymer quantization of the nuclei. The reaction rate constants obtained here agree extremely well with the experimentally measured rates. We demonstrate the feasibility of using ab-initio RPMD rate calculations in a realistic molecular system, and provide an interesting and important example for future investigations on reaction mechanisms dominated by quantum tunneling effects.</div> | Xinyang Li; Pengfei Huo | Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2021-05-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7591e469df41c20f457f0/original/investigating-tunneling-controlled-chemical-reactions-through-ab-initio-ring-polymer-molecular-dynamics.pdf |
6679ba0a01103d79c508c01d | 10.26434/chemrxiv-2024-p5q4d | Encoding Circularity in Polydiketoenamine Thermoplastics via Oxy-Functionalization | Here, we show that oxy-functionalization at specific sites along polydiketoenamine (PDK) backbones affects depolymerization rates by over three orders of magnitude, due to differences in distortion energies associated with reactive chain conformations in transition states for acidolysis. Site-specific oxy-functionalization, resulting in the fastest rates of acidolysis, opens the door to deconstructing linear PDK chain topologies for the first time, broadening the scope of applications for PDK plastics in a circular manufacturing economy, including chemically recyclable adhesives for a diverse range of surfaces. | Jeremy Demarteau; Alexander Epstein; Laura Reed; Nicodemo Ciccia; John Hartwig; Kristin Persson; Brett Helms | Physical Chemistry; Polymer Science; Organic Polymers; Polymerization kinetics; Physical and Chemical Properties; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6679ba0a01103d79c508c01d/original/encoding-circularity-in-polydiketoenamine-thermoplastics-via-oxy-functionalization.pdf |
6560aa0829a13c4d47e4c838 | 10.26434/chemrxiv-2023-t4vg7 | The Rise of the AI Scientist: Unleashing the Potential of Chat-GPT Powered Avatars in Virtual Reality Digital-twin Laboratories | Digital twin laboratories, accessible via the use of low-cost and portable virtual reality (VR) headsets, have emerged as an immensely powerful tool for chemical education and research collaboration. Having an immersive environment identical to that of a laboratory can provide scientists with a unique platform in which to plan future experiments, conduct laboratory tours, and train on specialist equipment. However, what digital twin laboratories currently lack is on-hand support of co-workers to assist with tasks such as locating chemicals, aiding with machine set-up, and issuing reminders regarding local laboratory health and safety rules Here we show how this key gap can be overcome with the use of knowledge-loaded Chat-GPT avatars in VR. We trained three different chat avatars to perform specialist functions crucial to working in a laboratory and obtained accurate and useful responses in up to 95% of cases, using a range of evaluation metrics including Human Evaluation, Set-Based F1 Scoring, and BERTScore. Our findings demonstrate the vast potential of this technology in harnessing the capabilities of AI assistants for scientists and enhancing immersive digital twin environments within VR settings. | Mae Taylor; Zaid Muwaffak; Matthew Penny; Blanka Szulc; Steven Brown; Andy Merritt; Stephen Hilton | Theoretical and Computational Chemistry; Chemical Engineering and Industrial Chemistry; Chemical Education; Chemical Education - General; Machine Learning; Artificial Intelligence | CC BY NC ND 4.0 | CHEMRXIV | 2023-11-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6560aa0829a13c4d47e4c838/original/the-rise-of-the-ai-scientist-unleashing-the-potential-of-chat-gpt-powered-avatars-in-virtual-reality-digital-twin-laboratories.pdf |
620f50be0aec1a535b21b99e | 10.26434/chemrxiv-2022-rwvtp | Hierarchical Porous Zeolitic Imidazolate Frameworks (ZIF-8) and ZnO@N-doped Carbon for Selective Adsorption and Photocatalytic Degradation of Organic Pollutants | Removing organic contaminants such as dyes from water is essential to purify wastewater. Herein, zeolitic imidazolate frameworks-8 (ZIF-8) and ZnO@N-doped C are effective adsorbent and photocatalysts for the adsorption and degradation of organic dyes. The materials showed effective and selective adsorption toward anionic dyes such as methyl blue (MeB) dye in the presence of fluorescein (FLU) dye. The adsorption capacities of ZnO@N-doped C for MeB and FLU dyes are 900 mg/g and 100 mg/g, respectively. According to UV–Vis diffuse reflectance spectra (DRS) data, ZnO@N-doped C has a lower bandgap (2.07 eV) than ZIF-8 (4.34 eV) and ZnO (3.12 eV). Thus, ZnO@N-doped C serves as an effective photocatalyst for the degradation of both dyes under UV exposure. The degradation efficiency capacity of the dye (50 mg/L) is > 90 % using 200 mg/L of the photocatalyst. The mechanism of adsorption and photocatalysis is investigated. The photodegradation pathway of the dye involved the generation of oxidative hydroxy radicals (OH•), which can degrade the dyes. The degradation products of FLU were recorded using mass spectrometry. | Hani Nasser Abdelhamid; Ahmed I.A. Soliman ; Aboel-Magd A. Abdel-Wahab | Materials Science; Inorganic Chemistry; Catalysis; Coordination Chemistry (Inorg.); Heterogeneous Catalysis | CC BY 4.0 | CHEMRXIV | 2022-02-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/620f50be0aec1a535b21b99e/original/hierarchical-porous-zeolitic-imidazolate-frameworks-zif-8-and-zn-o-n-doped-carbon-for-selective-adsorption-and-photocatalytic-degradation-of-organic-pollutants.pdf |
66a44fcec9c6a5c07a153f12 | 10.26434/chemrxiv-2024-gfp2t | Electrochemically Determined, and Structurally Justified Thermo-chemistry of H-atom Transfer on Ti-Oxo Nodes of the Colloidal Met-al–Organic Framework, Ti-MIL-125 | Titanium dioxide (TiO2) has long been employed as (photo)electrodes for reactions relevant to energy storage and re-newable energy synthesis. Proton-coupled electron transfer (PCET) reactions with equimolar amounts of protons and electrons at the TiO2 surface or within the bulk structure lie at the center of these reactions. Because a proton and an electron are thermochemically equivalent to an H-atom, these reactions are essentially H-atom transfer reactions. Ther-modynamics of H-atom transfer has a complex dependence on the synthetic protocol and chemical history of the elec-trode, the reaction medium, and many others; together, these complications preclude the understanding of the H-atom transfer thermochemistry with atomic-level structural knowledge. Herein, we report our success in employing open-circuit potential (EOCP) measurements to quantitatively determine the H-atom transfer thermochemistry at structurally well-defined Ti-oxo clusters within a colloidally stabilized metal–organic framework (MOFs), Ti-MIL-125. The free energy to transfer H-atom, Ti3+O–H bond dissociation free energy (BDFE), was measured to be 68 ± 2 kcal mol-1. To the best of our understanding, this is the first report on using EOCP measurements on any MOFs. The proton topology, the structural change upon the redox reaction, and BDFE values were further quantitatively corroborated using computational simula-tions. Furthermore, comparisons of the EOCP-derived BDFEs of Ti-MIL-125 to similar parameters in the literature suggest that EOCP should be the preferred method for quantitatively accurate BDFE calculations. The reported success in employ-ing EOCP for nanosized Ti-MIL-125 should lay the ground for thermochemical measurements of other colloidal systems, which are otherwise challenging. Implications of these measurements on Ti-MIL-125 as an H-atom acceptor in chemical reactions and comparisons with other MOFs/metal oxides are discussed. | Nazmiye Gokce Altincekic; Chance Lander; Ayman Roslend; Yihan Shao; Hyunho Noh | Inorganic Chemistry; Bonding; Electrochemistry; Supramolecular Chemistry (Inorg.); Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66a44fcec9c6a5c07a153f12/original/electrochemically-determined-and-structurally-justified-thermo-chemistry-of-h-atom-transfer-on-ti-oxo-nodes-of-the-colloidal-met-al-organic-framework-ti-mil-125.pdf |
667699175101a2ffa837f110 | 10.26434/chemrxiv-2024-xczfb | Active learning driven prioritisation of compounds from on-demand libraries targeting the SARS-CoV-2 main protease | FEgrow is an open-source software package for building congeneric series of compounds in protein binding pockets. For a given ligand core and receptor structure, it employs hybrid machine learning / molecular mechanics potential energy functions to optimise the bioactive conformers of supplied linkers and functional groups. Here, we introduce significant new functionality to automate, parallelise and accelerate the building and scoring of compound suggestions, such that it can be used for automated de novo design. We interface the workflow with active learning to improve the efficiency of searching the combinatorial space of possible linkers and functional groups, make use of interactions formed by crystallographic fragments in scoring compound designs, and introduce the option to seed the chemical space with molecules available from on-demand chemical libraries. As a test case, we target the main protease of SARS-CoV-2, identifying several small molecules with high similarity to molecules discovered by the COVID Moonshot effort, using only structural information from a fragment screen in a fully automated fashion. Finally, we order and test 19 compound designs, of which three show weak activity in a fluorescence-based Mpro assay, but work is needed to further optimise the prioritisation of compounds for purchase. | Ben Cree; Mateusz Bieniek; Siddique Amin; Akane Kawamura; Daniel Cole | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Drug Discovery and Drug Delivery Systems; Computational Chemistry and Modeling; Machine Learning | CC BY 4.0 | CHEMRXIV | 2024-06-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/667699175101a2ffa837f110/original/active-learning-driven-prioritisation-of-compounds-from-on-demand-libraries-targeting-the-sars-co-v-2-main-protease.pdf |
65aa7151e9ebbb4db984dc9f | 10.26434/chemrxiv-2024-kd6sg | Signal-triggered release of allyl-caged tertiary amine drugs from polymer hydrogels | We present a new method to obtain tertiary amine-based prodrugs with dual functionality, enabling (i) signal-triggered drug activation and (ii) covalent incorporation in polymer materials through a clickable azido-group unit on the molecular prodrug scaffold. Using nucleophilic substitution on an electron deficient azido-phenyl allyl bromide scaffold, we were able to obtain prodrugs from a variety of amine drug candidates. Subsequent drug activation was initiated by using S or N-terminal biomarker nucleophiles including amino acids, a neurotransmitter, and glutathione as chemical signals. Hydrogel scaffolds labelled with anti-cancer or antibiotic prodrugs were tested in aqueous and cellular media. Through this strategy, we achieved controlled drug release for in vitro cancer models (2D monolayer), which showed complete wound closure inhibition of A549 small lung cancer cells upon signal activation. We anticipate that this strategy for the development of responsive prodrug-conjugate incorporated materials will lead to further advancements in drug delivery and specialized therapeutics. | Rienk Eelkema; Benjamin Klemm; Magherita Tavasso; Irene Piergentili; Max Satijn; Tobias Breve; Pouyan Boukany | Biological and Medicinal Chemistry; Organic Chemistry; Polymer Science; Organic Compounds and Functional Groups; Drug delivery systems; Hydrogels | CC BY 4.0 | CHEMRXIV | 2024-01-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65aa7151e9ebbb4db984dc9f/original/signal-triggered-release-of-allyl-caged-tertiary-amine-drugs-from-polymer-hydrogels.pdf |
60c7484c469df42640f439a9 | 10.26434/chemrxiv.11316497.v2 | How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? an Interlaboratory Study | <p>Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an <i>interlaboratory reproducibility</i> of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm<sup>-1</sup> in the measured total ionic conductivity (1.3 – 5.8 mScm<sup>-1</sup> for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.</p> | Saneyuki Ohno; Tim Bernges; Johannes Buchheim; Marc Duchardt; Anna-Katharina Hatz; Marvin Kraft; Hiram Kwak; A. L. Santhosha; Zhantao Liu; Nicolo Minafra; Fumika Tsuji; Atsushi Sakuda; Roman Schlem; Shan Xiong; Zhenggang Zhang; Philipp Adelhelm; Hailong Chen; Akitoshi Hayashi; Yoon Seok Jung; Bettina Lotsch; Bernhard Roling; Nella Vargas; Wolfgang Zeier | Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7484c469df42640f439a9/original/how-certain-are-the-reported-ionic-conductivities-of-thiophosphate-based-solid-electrolytes-an-interlaboratory-study.pdf |
65679e8529a13c4d4748d560 | 10.26434/chemrxiv-2023-m3csm | Ozone Processing in the Dairy Sector: A review of applications, quality impact and implementation challenges | The impact on the natural characteristics of dairy products during thermal processing warrants the investigation of non-thermal techniques. Ozone has not only arisen as an inactivation treatment for milk and its products with minimal effects on the quality parameters. But has also been proven efficient for reducing biofilms, antibiotics, and aflatoxins, and used for equipment sterilization, air disinfection, sanitization, and de-sludge treatments. This review discusses the updates on the effect of ozone processing on the microbiological, physiochemical, nutri-functional, and sensory quality of milk and milk products. Other applications of ozone in the dairy processing sector (storage rooms disinfection, wastewater treatment, benefits in CIP, toxin reduction), current industrial scenario, and regulatory and safety requirements in the facility dealing with ozone have also been discussed alongside the research gaps and challenges. | Pranav Vashisht; Digvijay Verma; Anto Pradeep Raja Charles; Gursharn Singh Saini; Sonali Sharma; Lovepreet Singh; Shikhadri Mahanta; Snehadri Mahanta; Khushi Singh; Gaurav Gaurav | Agriculture and Food Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-12-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65679e8529a13c4d4748d560/original/ozone-processing-in-the-dairy-sector-a-review-of-applications-quality-impact-and-implementation-challenges.pdf |
6133abc7abeb63ca0ec88f5d | 10.26434/chemrxiv-2021-l9xw5 | A transient initiator for polypeptoids post-polymerization α-functionalization via activation of thioester group | Here we introduce a post-polymerization modification method of an α-terminal functionalized poly-(N-methyl-glycine), also known as polysarcosine. We utilized 4-(methylthio)phenyl piperidine-4-carboxylate as an initiator for the ring-opening polymerization of N-methyl-glycine-N-carboxyanhydride followed by oxidation of the thioester group to yield an α-terminal reactive 4-(methylsulfonyl)phenyl piperidine-4-carboxylate polymer. This represents an activated carboxylic acid terminus, allowing straightforward modification with nucleophiles under mild reaction conditions and provides the possibility to introduce a wide variety of nucleophiles as exemplified using small molecules, fluorescent dyes and model proteins. The new initiator yielded polymers with well-defined molar mass, low dispersity and high end-group fidelity, as observed by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy and matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectroscopy. The introduced method could be of great interest for bioconjugation, but requires optimization, especially for protein conjugation. | Solomiia Borova; Christine Schlutt; Joachim Nickel; Robert Luxenhofer | Polymer Science; Organic Polymers | CC BY 4.0 | CHEMRXIV | 2021-09-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6133abc7abeb63ca0ec88f5d/original/a-transient-initiator-for-polypeptoids-post-polymerization-functionalization-via-activation-of-thioester-group.pdf |
64a5094c6e1c4c986bd371bd | 10.26434/chemrxiv-2023-pnhc4 | SPOTLIGHT: Structure-based Prediction and Optimization Tool for LIgand Generation on Hard-to-drug Targets - Combining Deep Reinforcement Learning with Physics-based de novo drug design | We present SPOTLIGHT - a proof-of-concept for a method capable of designing a diverse set of novel drug molecules through a rule-based approach. The model constructs molecules atom-by-atom directly at the active site of a given target protein. SPOTLIGHT has the potential to be faster and more efficient than many existing methods that rely on generation cycles and docking/scoring to optimize their molecules. It requires no apriori information about known ligands as the molecule construction is purely based on classical interactions. We patch the model with deep reinforcement learning (RL) by using a Graph Convolution Policy Network (GCPN) to tune molecule-level properties directly during the generation phase. Our method has shown promising results when applied to the ATP binding pocket of the well-studied HSP90 protein. We show that our model upholds diversity while successfully producing strong binders to the protein. Given the stochasticity at each step, we do not expect it to reproduce known ligands exactly. However, we show how it uses significant fragments of known ligands as substructures while also providing an alternate way for tuning between similarity and novelty. | Venkata Sai Sreyas Adury; Arnab Mukherjee | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Machine Learning | CC BY 4.0 | CHEMRXIV | 2023-07-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64a5094c6e1c4c986bd371bd/original/spotlight-structure-based-prediction-and-optimization-tool-for-l-igand-generation-on-hard-to-drug-targets-combining-deep-reinforcement-learning-with-physics-based-de-novo-drug-design.pdf |
60c7500b567dfe1421ec57e0 | 10.26434/chemrxiv.12271841.v2 | Carbon Species Solvated in Molten Carbonate Electrolyser Cell from First-Principles Simulations | We study the solvation of molecules and ions that are key in the context of Molten Carbonate Electrolyser Cells using first-principles simulations. Focusing on the electroreduction of CO<sub>2</sub> to CO in a molten carbonate medium, we investigate the solvation of both the reactant CO<sub>2</sub> and the product CO in the eutectic LiKCO<sub>3</sub>, (containing 62 % Li<sub>2</sub>CO<sub>3</sub>, 38 % K<sub>2</sub>CO<sub>3</sub>,). CO<sub>2</sub> is found to spontaneously react with the carbonate ions to form the transient pyrocarbonate species, C<sub>2</sub>O<sub>5</sub><sup>2-</sup>. To investigate the similar reaction that could occur with CO and CO<sub>3</sub><sup>2-</sup> to form an oxalate, we simulated that species and found it to be stable in the melt, supporting this hypothesis. We further present the solvation of O<sup>2-</sup>, finding that it shows preferential formation of a complex with four lithium cations in a tetrahedral arrangement. Estimates of the diffusion coefficients of these species are then reported, showing that CO has the faster diffusion of all the molecules and ions studied.<br /> | Antoine Carof; François-Xavier Coudert; Dario Corradini; Dominika Lesnicki; elsa desamele; Rodolphe Vuilleumier | Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7500b567dfe1421ec57e0/original/carbon-species-solvated-in-molten-carbonate-electrolyser-cell-from-first-principles-simulations.pdf |
650c2839b927619fe78e81cd | 10.26434/chemrxiv-2023-sgcct | Antibacterial marinopyrroles and pseudilins act as protonophores | Elucidating the mechanism of action (MoA) of antibacterial natural products is crucial to evaluating their potential as novel antibiotics. The marinopyrroles, pentachloropseudilin, and pentabromopseudilin are densely halogenated, hybrid pyrrole-phenol natural products with potent activity against Gram-positive bacterial pathogens like Staphylococcus aureus. However, the exact way in which they exert this antibacterial activity has not been established. In this study, we explore their structure-activity relationship, determine their spatial location in bacterial cells, and investigate their MoA. We show that the natural products share a common MoA based on membrane depolarization and dissipation of the proton motive force (PMF) that is essential for cell viability. The compounds show potent protonophore activity, but do not appear to destroy the integrity of the cytoplasmic membrane via the formation of larger pores or interfere with the stability of the peptidoglycan sacculus. Thus, our current model for the antibacterial MoA of marinopyrrole, pentachloropseudilin, and pentabromopseudilin stipulates that the acidic compounds insert into the membrane and transport protons inside the cell. This MoA may explain many of the deleterious biological effects in mammalian cells, plants, phytoplankton, viruses, and protozoans that have been reported for these compounds. | Gabriel Castro-Falcon; Jan Straetener; Jan Bornikoel; Daniela Reimer; Trevor Purdy; Florence Schempp; Dennis Liu; Roger Linington; Heike Brötz-Oesterhelt; Chambers Hughes | Biological and Medicinal Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-09-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/650c2839b927619fe78e81cd/original/antibacterial-marinopyrroles-and-pseudilins-act-as-protonophores.pdf |
67d8bd386dde43c9082fb30d | 10.26434/chemrxiv-2025-r1nf2 | First Observation and Mitigation of Ni-Leaching Mediated Degradation to Enhance Stability of Ni-rich Layered Cathodes in Solid-State Batteries | Cathode–solid electrolyte (SE) interfacial stability issues pose a significant challenge to stable and high-power operations of all-solid-state batteries, which promise greater energy density, thermal stability, and safety than the current liquid electrolyte-based Li-ion technology. For technologically important Ni-rich NMCs (LiNixMnyCozO2 or NMCxyz; x/y/z: Ni/Mn/Co stoichiometry) with sulfide SEs, redox-mediated instability of the SE is often blamed for rapid cathode deterioration. Here, in-depth spectroscopic and electrochemical analyses of Ni-rich NMCs with a promising sulfide SE reveal rapid interfacial degradations underpinned by hitherto unknown selective Ni leaching from the NMC particles, sparking accelerated capacity fading and poor thermal stability. We demonstrate that introducing a functionalized conductive carbon in the cathode subdues the oxidative degradation of the sulfide SE into reactive polysulfides that trigger the NMC degradation. Consequently, NMC622 and NMC811-based cells display attractive active material utilization, enhanced stability, and excellent rate capability and thermal stability – together with a very high average Coulombic efficiency of 99.8% even for high-temperature cycling, which otherwise compounds cycling instability. This study unveils a previously unforeseen interfacial degradation of a technologically critical cathode-SE combination and presents a scalable approach to its in situ regulation, enabling remarkable performance improvement. | Abhirup Bhadra; Jacob Otabil Bonsu; Maxime Brunisholz; Tongjun Luo; Lars Thomsen; Wesley Dose; Dipan Kundu | Physical Chemistry; Energy; Energy Storage; Electrochemistry - Mechanisms, Theory & Study; Spectroscopy (Physical Chem.); Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67d8bd386dde43c9082fb30d/original/first-observation-and-mitigation-of-ni-leaching-mediated-degradation-to-enhance-stability-of-ni-rich-layered-cathodes-in-solid-state-batteries.pdf |
676204c7fa469535b9eebe04 | 10.26434/chemrxiv-2024-q9k30 | Direct Observation of Three Chiral Conformers of an Atomically Precise Metal Nanoparticle | Atomically precise nanoclusters (NCs) have attracted a lot of attention owing to their many interesting properties and applications. Although such clusters could be considered small molecules due to their discrete atomic compositions, their size and complexity push them into a distinct regime where the line between molecule and material is blurred. On the fundamental side, they can provide a testbed for understanding structure-property relationships in nanomaterials. Hence, their isomerism is of intrinsic significance. In this work, we report the atomically precise structure of three Cu14 NC conformers, i.e., NCs with the same chemical formula and atomic connectivity but with varying bond angles and distances, obtained through X-ray crystallography. Interestingly, all three conformers exhibit chirality and co-crystallize in the same lattice structure. Since interconversion of each conformer and its chiral counterpart is possible without breaking and remaking bonds, these NCs constitute a set of atropisomers. The structure of our Cu14 NC highlights the various sources of isomerism one can observe at the nanoscale. These subtle yet identifiable differences represent something like a minimal unit of structural change, facilitating future investigation of structure-property relationships. | Anish Kumar Das; Swastik Hegde; Toby J. Woods; Vaibhav S. Wani; Mikael P. Backlund | Inorganic Chemistry; Nanoscience; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-12-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/676204c7fa469535b9eebe04/original/direct-observation-of-three-chiral-conformers-of-an-atomically-precise-metal-nanoparticle.pdf |
66443efb91aefa6ce10a3d0a | 10.26434/chemrxiv-2024-9g6hj | Hydrogen-driven boron nitride phase differentiation during the epitaxial nucleation on the diamond (001) surface | Cubic boron nitride (cBN) and diamond, sharing identical lattice structures, currently garner significant interest for next-generation high-power, high-frequency electronics. Despite successful heteroepitaxial synthesis of single-crystal cBN on diamond substrates via chemical vapor deposition (CVD), limited understanding of cBN growth blurs the origin of mixed BN phases under some synthesis conditions. Here, employing first-principles calculations based on a nanoreactor scheme, we study the cBN epitaxial nucleation on the diamond (001) surface under a limited-H condition. The discovered mechanism is initiated by inserting BN units into the surface dimer bond, leading to an island formation, which initially expands laterally - along the diamond surface - but rapidly switches to out-of-plane 3-dimensional growth. A high reaction barrier on the surface (~0.4-0.8 eV, 1300 K) aligns with challenging nucleation observed in experiments. Examining the environment hydrogen concentration effect revealed the origin of diverse BN phases experimentally, i.e., hydrogen deficiency favors amorphous BN (aBN) growth, whereas excessive hydrogen significantly raises sp2 bonding fraction, resulting in hexagonal BN (hBN) layers. Our results offer valuable guidance for the controllable synthesis of BN phases and advance research toward potential cBN electronics. | Ting Cheng; Ksenia V. Bets; Boris I. Yakobson | Materials Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-05-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66443efb91aefa6ce10a3d0a/original/hydrogen-driven-boron-nitride-phase-differentiation-during-the-epitaxial-nucleation-on-the-diamond-001-surface.pdf |
64a3a14c6e1c4c986bc566f3 | 10.26434/chemrxiv-2023-7sm53 | Cloneable Selenium Nanoparticles As Multi-modal Bio-imaging Contrast Agents | A cloneable NanoParticle (cNP) is an inorganic nanoparticle that is synthesized by a protein. The protein determines the elemental composition, size, morphology, and other properties of the nanoparticle. Here, we describe the use of a cloneable Selenium NanoParticle (cSeNP) as a cloneable imaging contrast agent in electron microscopy, fluorescence microscopy, and X-ray computed tomography. Combined, these three imaging modalities produce images of biological length scales spanning meters to angstroms but are difficult to correlate. The cSeNP is comprised of an NADPH dependent enzyme that reduces selenodiglutathione to zerovalent Se precipitates. SeNP binding peptides fused to the enzyme ligate the Se precipitates, retain them at the enzyme, and regulate SeNP size to ~5 nm inside cells. The cSeNP-protein can be genetically fused to any protein-of-interest, creating a chimeric protein-of-interest-cSeNP. The cSeNPs endow the protein-of-interest with distinguishable contrast in X-ray and EM images, due to the contrast of SeNPs in these imaging modalities relative to biological background. The cSeNPs can react spontaneously with transition metals such as Znn+ or Cun+, forming fluorescent metal-selenides, imageable in florescence microscopy. The cSeNP, therefore, represents a cloneable imaging contrast agent that facilitates location and correlation of proteins-of-interest across all biological length scales. | Kanda Borgognoni; Bradley Guilliams; Rachel Cohen; Christopher Ackerson | Biological and Medicinal Chemistry; Biophysics; Cell and Molecular Biology; Chemical Biology | CC BY 4.0 | CHEMRXIV | 2023-07-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64a3a14c6e1c4c986bc566f3/original/cloneable-selenium-nanoparticles-as-multi-modal-bio-imaging-contrast-agents.pdf |
60c74cb8bdbb8914e7a3985d | 10.26434/chemrxiv.12525284.v1 | An Improved Protocol for the Synthesis and Purification of Yariv Reagents | Yariv reagents are widely used tools to study plant proteoglycans known as the Arabinogalactan proteins (AGPs). Despite widespread use of the Yariv reagent in the study of AGPs and several reports of synthetic protocols, there remains a lack of a simple procedure to obtain pure Yariv reagents. We report our optimized protocols to address the purification issues faced upon synthesis of Yariv reagents. Additionally, we report challenges that make characterization difficult such as peak broadening in NMR due to Yariv-water interactions. We also show ways of processing Yariv reagents to overcome the characterization issues caused by peak broadening. | Amit Basu; Raghuraj Hoshing; Michael Saladino; Helene Kuhn; David Caianiello; Robert Lusi | Bioorganic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74cb8bdbb8914e7a3985d/original/an-improved-protocol-for-the-synthesis-and-purification-of-yariv-reagents.pdf |
67ad1d49fa469535b917a988 | 10.26434/chemrxiv-2025-pkb6x | Linker-Dependent Gas Adsorption of Network Polymers Using Aminated Trinaphtho[3.3.3]propellane | Designed molecular-sized cavities is key to efficient transport, storage, and separation of small molecules. Herein, we report that the adsorption properties of void-containing polymers were altered by changing linker units for condensation with hexa-aminated trinaphtho[3.3.3]propellane as the partner. Aldehyde linkers resulted in formation of N=C–NH perimidine-like segments in polymer structures and showed higher selectivity for alkanes over carbon dioxide than network polymers with NH–B– NH moieties derived from boronic esters. Use of 1,3,5-trifunctionalized linkers, which are expected to give smaller cavities, led to a network polymer containing NH–B–NH moieties exhibiting size exclusion of n-butane, while fairly retaining adsorption capacity for ethane and carbon dioxide. | Kenichi Kato; Seina Okada; Motohiro Mizuno; Nobuyoshi Seto; Ryo Iwano; Shunsuke Ohtani; Tomoki Ogoshi | Organic Chemistry; Polymer Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2025-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67ad1d49fa469535b917a988/original/linker-dependent-gas-adsorption-of-network-polymers-using-aminated-trinaphtho-3-3-3-propellane.pdf |
65117998ed7d0eccc32f7fe3 | 10.26434/chemrxiv-2023-bm4bm | Dual FGFR-targeting and pH-activable Smart Ruthenium-Peptide Conjugates for targeted therapy of Breast Cancer | Dysregulation of Fibroblast Growth Factor Receptors (FGFRs) signaling has been associated with breast cancer, yet employing FGFR-targeted delivery systems to improve cytotoxic agents is still sparsely exploited. Herein, we report four new bi-functional ruthenium-peptide conjugates (RuPCs) with FGFR-targeting and pH-dependent releasing abilities, envisioning the selective delivery of cytotoxic Ru complexes to FGFR(+)-breast cancer cells, upon specific accumulation and controlled activation at the acidic tumoral microenvironment. The antiproliferative potential of the RuPCs and active Ru complexes was evaluated in four breast cancer cell lines with different FGFR expression levels (SK-BR-3, MDA-MB-134-VI, MCF-7, and MDA-MB-231) and in the normal human dermal fibroblasts (HDF) cell line, at pH 6.8 and 7.4 that mimics the tumor microenvironment and normal tissues/bloodstream, respectively. The RuPCs showed higher cytotoxicity in cells with higher level of FGFR expression at acidic pH. Additionally, RuPCs showed up to 6-fold higher activity in the FGFR(+) breast cancer lines compared to the normal line. The release profile of Ru complexes from RuPCs corroborates the antiproliferative effects observed. Remarkably, the cytotoxicity and releasing ability of RuPCs were shown to be strongly dependent on the peptide conjugation position in the Ru complex. Complementary molecular dynamic simulations and computational calculations were performed to help interpret these findings at the molecular level. In summary, we identified a lead bi-functional RuPC that holds strong potential as a FGFR-targeted chemotherapeutic agent. | João Franco Machado; Marco Sá; Inês Pires; Miguel Silva; Fernanda Marques; Jaime A. S. Coelho; Filipa Mendes; M. Fátima M. Piedade; Miguel Machuqueiro; María Angeles Jiménez; Maria Helena Garcia; João D. G. Correia; Tânia Morais | Inorganic Chemistry; Organometallic Chemistry; Bioinorganic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-09-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65117998ed7d0eccc32f7fe3/original/dual-fgfr-targeting-and-p-h-activable-smart-ruthenium-peptide-conjugates-for-targeted-therapy-of-breast-cancer.pdf |
60c73fb7bdbb899560a38057 | 10.26434/chemrxiv.7471397.v1 | Using Melanogenesis to Study Antioxidants | Building upon our research on the non-enzymatic
synthesis of melanins, we explored the possibility that the reactions involved
in the synthesis of melanins could serve as the basis for the study of and
search for compounds with anti-oxidant properties. The synthesis of melanins can
be achieved through air-mediated oxidation or through
reactive-oxygen-species-mediated oxidation and can readily be monitored by the
changes in color. In addition, a broad variety of different precursors can be
used to generate melanins. Thus, using melanogenesis as the foundation for an
anti-oxidant assay, one can evaluate the effects of potential anti-oxidants
against air- or reactive-oxygen-species mediated oxidations and evaluate the
consistency of the anti-oxidant effects when different precursors for
melanogenesis are used. | Koen Vercruysse; Iesha Brown; Sha'Kendria Summers | Biochemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2018-12-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73fb7bdbb899560a38057/original/using-melanogenesis-to-study-antioxidants.pdf |
67236d82f9980725cfae5a30 | 10.26434/chemrxiv-2024-wkvw7 | Triptycene-based 2.5D Metal-Organic Frameworks: Atomically Ac-curate Structures and One-Dimensional Antiferromagnetism from Hydrogen-Bonding Bridged Protonated Building Units | Recent advances in two-dimensional π-d conjugated conductive metal-organic frameworks (2D cMOFs) have highlighted their potential as sophisticated, active materials in electrochemical energy storage devices, electrocatalysis, and sensors. However, a lack of high-quality structural characterization severely limits understanding their physical properties. Specifically, rapid and irre-versible nucleation and aggregation, induced by strong interlayer π-π interactions, have hindered crystal growth in these cMOFs. In this study, by utilizing triptycene-based ligands, 2,3,6,7,14,15-hexahydroxy triptycene (HHTripH2) and 9,10-dimethyl-2,3,6,7,14,15-hexahydroxy triptycene (HHTripMe2), we successfully mitigated interlayer π-π interactions and achieved SCXRD quality crystals of two triptycene-based 2D MOFs: Cu3(TripH2)2 and Cu3(TripMe2)2. The crystal structures reveal a protonated catechol ligand and an interlayer hydrogen-bonding-guided stacking motif. Notably, the steric effect of the two axial methyl groups in the TripMe2 ligand modifies the structure of Cu3(TripMe2)2 from regular AB stacking to interpenetration, significantly enhancing the stability of the crystals. ESR and susceptibility measurements indicate that these modifications facilitate hydrogen-bonding-guided 1D antiferromagnetic behavior in the Cu(cat)2 secondary building units (SBUs). This study reveals the critical roles of high-quality crystal structures and protonation/deprotonation of coordinating atoms in understanding the properties of 2D MOFs. | Qi Chen; Kunio Awaga; Zhongyue Zhang | Materials Science; Inorganic Chemistry; Coordination Chemistry (Inorg.); Magnetism; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-11-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67236d82f9980725cfae5a30/original/triptycene-based-2-5d-metal-organic-frameworks-atomically-ac-curate-structures-and-one-dimensional-antiferromagnetism-from-hydrogen-bonding-bridged-protonated-building-units.pdf |
60c74a47469df4a990f43ce3 | 10.26434/chemrxiv.12130011.v2 | Overcoming Back Electron Transfer Facilitates the Implementation of Electron Donor-Acceptor Complexes in Catalysis | Electron donor-acceptor (EDA) complexes can
controllably generate radicals under mild conditions through selective
photoexcitation events. However, unproductive reactivity from fast deactivation
of the photoexcited complexes through back electron transfer has slowed the
development of EDA complexes in synthetic methodology. Here, we disclose the
study of EDA complexes derived from 2-methoxynaphthalene donor and acylated
ethyl isonicotinate <i>N</i>-oxide acceptor that undergo a fast N–O bond
fragmentation event upon photoexcitation. This reaction design not only
overcomes the limitations of back electron transfer but also enables the
regeneration of the donor species, representing a rare example EDA
photochemistry in a catalytic regime. The synthetic utility is demonstrated
through visible light-driven radical trifluoromethylation and Minisci
alkylation reactions. The scalability of the EDA complex promoted reaction evidenced
by the successful multigram-scale trifluoromethylation of methyl N-Boc
pyrrole-2-carboxylate in a continuous flow manifold. | Edward McClain; Timothy Monos; Mayuko Mori; Joel Beatty; Corey Stephenson | Organic Synthesis and Reactions; Photochemistry (Org.); Organocatalysis; Photocatalysis; Redox Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74a47469df4a990f43ce3/original/overcoming-back-electron-transfer-facilitates-the-implementation-of-electron-donor-acceptor-complexes-in-catalysis.pdf |
60c73e190f50dbebeb3955e6 | 10.26434/chemrxiv.6668996.v1 | Light- or Dark-Colored, L-DOPA-Based Melanins | <p>This report is a
continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis
of melanin-like pigments.
We
synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub>
</sub>oxidation. We compared their physic-chemical properties and evaluated
their capacity to affect the interleukin release from immune cells. The use of
higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like
materials with a distinct chemical signature in their FT-IR spectra and a
lighter color. All pigments enhanced the interleukin release from immune cells. The possibility
that lighter-colored melanins can be generated is discussed in the context of
the importance of melanin-based pigmentation in human physiology.</p> | Koen Vercruysse; Margaret M. Whalen | Biochemistry; Cell and Molecular Biology; Physical and Chemical Properties | CC BY NC ND 4.0 | CHEMRXIV | 2018-06-26 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e190f50dbebeb3955e6/original/light-or-dark-colored-l-dopa-based-melanins.pdf |
60c74aabf96a0027ca2874b6 | 10.26434/chemrxiv.12240338.v1 | Transport Phenomena at Test and Control Lines in Lateral Flow Immunoassays Reveal a Path to Expanding Their Dynamic Range | <p>This study presents theoretical underpinnings for how the dynamic range of a lateral flow immunoassay (LFIA) may be expanded by real-time imaging. The dynamic range of a sandwich LFIA is limited by the ‘hook effect’, according to which, test line signal intensities reduce with increasing analyte concentration beyond a threshold analyte concentration. Rey et al. (<i>Anal Chem</i>, 2017, 89(9)) have shown experimentally that the hook effect in sandwich LFIAs may be mitigated by real-time imaging of test and control line, but theoretical understanding of the transport phenomena that govern this phenomenon is lacking. In fact, transport phenomena at the control line of an LFIA have never been modelled. In this paper, we use a transport-reaction model to understand how the kinetics of signal generation at the test and control lines of an LFIA relate to analyte concentration. Using this model, we developed a method for determination of analyte concentration accurately over a much larger range than the traditional end-point detection method. The model was validated using a commercially available lateral flow assay (home pregnancy test) on which real time imaging was conducted using a time-lapse app on a smartphone; there was a strong agreement between the predictions of our model and experiments results. The newly developed readout method increased the dynamic range for the detection of human chorionic gonadotropin (hCG) to 3 orders of magnitude (compared to ~1.5 orders of magnitude achieved by traditional end-point detection), without any modification to the test strip.</p> | Sathishkumar N; Bhushan Toley | Analytical Chemistry - General | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74aabf96a0027ca2874b6/original/transport-phenomena-at-test-and-control-lines-in-lateral-flow-immunoassays-reveal-a-path-to-expanding-their-dynamic-range.pdf |
6770babafa469535b91ed412 | 10.26434/chemrxiv-2025-2492b | Synthesis of Functionalized Biochar Hybrid Particles for Textile Wastewater Treatment | In this study, biochar was synthesized using Mustard Seed cake as raw biomass with the carbonization method. Biochar materials, namely, Mustard Seed cake biochar was prepared at 500 °C temperatures. This biochar was further modified with Conc. Nitric acid solution. The surface modified biochar was characterized using Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The potential of synthesized adsorbent was evaluated for the elimination of methylene blue and malachite green dye from textile wastewater as a function of numerous provisions, namely, contact time, pH of solution, number of adsorbents, and initial concentrations of adsorbates. Various kinetic and isotherm models were examined to consider and explain the sorption mechanisms. Methylene Blue can be removed 97% of the time with functionalized biochar (0.03g/25 ml). Like that, 0.06g/25 ml of functionalized biochar may remove 95% of the maximal amount of Malachite Green. Surface Functionalized biochar showed high pollutant removal efficiency with maximum removal of % for MG and % for MB dye. Kinetic studies showed that the pseudo-second-order kinetic model showed better agreement with kinetic
experimental data than other kinetic models. The linear Isotherm models showed that Freundlich, and Temkin isotherms are best fitted on the adsorption of Dyes with R2 =0.998. The results of this research showed that the synthesized adsorbents can be applied efficiently for various cycles to remove MG and MB from textile wastewater on pilot scale.
| Muhammad Irfan; Muhammad Noman Tahir; Muhammad Shahid; Saz Muhammad | Materials Science; Catalysis; Analytical Chemistry; Biochemical Analysis; Biocatalysis; Nanocatalysis - Reactions & Mechanisms | CC BY 4.0 | CHEMRXIV | 2025-01-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6770babafa469535b91ed412/original/synthesis-of-functionalized-biochar-hybrid-particles-for-textile-wastewater-treatment.pdf |
642c523716782ec9e6579f8c | 10.26434/chemrxiv-2023-9pdgb | Hexafluoroisopropanol (HFIP) as a multifunctional agent in gold-catalyzed cycloisomerizations and sequential transfor-mations | Despite the unique position of gold catalysis in contemporary organic synthesis, this area of research is notorious for requiring activators and/or additives that enable catalysis by generating cationic forms of gold catalysts. Cycloisomeriza-tion reactions occupy a significant portion of the gold-catalyzed reaction space, while they represent a diverse family of reactions which are frequently utilized in synthesis. Herein, hexafluoroisopropanol (HFIP) is shown to be a uniquely simple tool for gold-catalyzed cycloisomerizations, rendering the use of external activators obsolete, and leading to high-ly active catalytic systems with ppm levels of catalyst loading in certain cases. HFIP assumes a dual role as solvent and activator, operating via the dynamic activation of the Au-Cl bond through hydrogen bonding, which initiates the catalytic cycle. This special mode of catalysis can enable efficient and scalable cyclization reactions of propargylamides and ynoic acids with simple [AuCl(L)] complexes. A thorough screening of ancillary ligands and counter anions has been per-formed, establishing this methodology as an alternative to elaborate ligand/catalyst design and to the use of activators. Additionally, this concept is applied in C-C bond forming cycloisomerization reactions leading to 2H-chromenes and to the design of catalytic systems for sequential or one-pot transformations leading to activated ketoesters, a functionalized N-heterocyclic carbene (NHC) precursor salt, and a compound bearing the bioactive indole core, among others. Im-portantly, through mechanistic investigations including a “snapshot” of the species of interest in the solid state, we were able to unambiguously detect the key H-bonding interaction between HFIP and the gold catalyst, shedding light on the intermolecular mode of activation that enables catalysis. In the cases examined herein, HFIP is not only an excellent sol-vent, but also a potent activator and a valuable synthetic handle when incorporated into functional groups of products. | Nikolaos Tzouras; Leandros Zorba; Entzy Kaplanai; Nikolaos Tsoureas; David Nelson; Steven Nolan; Georgios Vougioukalakis | Organic Chemistry; Catalysis; Organometallic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/642c523716782ec9e6579f8c/original/hexafluoroisopropanol-hfip-as-a-multifunctional-agent-in-gold-catalyzed-cycloisomerizations-and-sequential-transfor-mations.pdf |
65ace0d766c1381729ee959e | 10.26434/chemrxiv-2023-8v37k-v2 | Overview of Electrode Advances in Commercial
Li-ion Batteries | This review paper presents a comprehensive analysis of the electrode materials used for Li-ion batteries. We explore key areas of electrode materials for Li-ion batteries and discuss the advancements and challenges associated with them. Through an extensive literature review, we identify the current state of research, methodologies, and applications related to Li-ion battery electrodes. Our study covers a wide range of subtopics, including the theoretical aspects of the basic functioning of lithium-ion batteries and the crystal structures of different electrode materials. Additionally, we discuss emerging trends and future directions in the development of high-performance commercial battery electrodes, providing insights into promising avenues for further research. By synthesizing existing knowledge and analyzing the latest research, this review aims to provide a valuable resource for researchers, practitioners, and stakeholders interested in developing state-of-the-art high-performance Li-ion batteries. The findings and perspectives presented in this paper contribute to a deeper understanding of the electrode materials for Li-ion batteries and their advantages and disadvantages, ultimately fostering advancements and innovation in the commercial electrode technology. | SARTHAK PATNAIK | Materials Science; Energy; Energy Storage | CC BY 4.0 | CHEMRXIV | 2024-01-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65ace0d766c1381729ee959e/original/overview-of-electrode-advances-in-commercial-li-ion-batteries.pdf |
626c8257742e9fb58470a94e | 10.26434/chemrxiv-2022-l60sc | Synthesis of Highly Congested Tertiary Alcohols via the [3,3] Radical Deconstruction of Breslow Intermediates | Pericyclic processes such as [3,3]-sigmatropic rearrangements leading to the rapid generation of molecular complexity constitute highly valuable tools in organic synthesis. Herein, we report the formation of particularly hindered tertiary alcohols via rearrangement of Breslow intermediates formed in situ from readily available N-allyl thiazolium salts and benzaldehyde derivatives. Experimental mechanistic studies performed suggest that the reaction proceeds via a close radical pair which recombine in a regio- and diastereoselective manner, formally leading to [3,3]-rearranged products. | Roger Machín Rivera; Nikolas Burton; Luke Call; Marshall Tomat; Vincent Lindsay | Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2022-05-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/626c8257742e9fb58470a94e/original/synthesis-of-highly-congested-tertiary-alcohols-via-the-3-3-radical-deconstruction-of-breslow-intermediates.pdf |
60c747c9337d6c937fe273fc | 10.26434/chemrxiv.11788947.v1 | Indium Hydroxide/Silver/Carbon Nanocomposite: Synthesis via Galvanic Reaction between In Nanoparticles and Silver Nitrate, Characterization and Its Photocatalytic Activity | <p>Sub-10 nm indium metal
nanoparticles (In NPs) stabilized on conductive carbon were reacted with silver
nitrate in dark in water at room temperature in a galvanic replacement manner
to produce indium hydroxide/silver/carbon nanocomposite (In(OH)<sub>3</sub>/Ag/C). The
chosen carbon imparted colloidal stability, high surface area and water
dispersibility suitable for photodegradation of harmful dyes in water. The size
and shape of indium hydroxide and silver nanoparticles produced were found to
be similar to that of the In NPs started with. The nanocomposite was
characterized by Transmission Electron Microscopy (TEM), Energy Dispersive
X-ray Spectroscopy (EDAX), Powder X-Ray Diffraction (PXRD) and
Thermogravimetric Analysis (TGA). The galvanic reaction between In NPs and
silver nitrate was tracked with UV-Vis Spectroscopy in a control experiment
without conducting carbon to confirm that the reaction was indeed
thermodynamically spontaneous as indicated by the positive electromotive force
(EMF) of +1.14 V calculated for In/Ag<sup>+</sup> redox couple. The nanocomposite’s
photocatalytic performance was evaluated to be 90% under UVC radiation
when 10 ppm of methylene blue and 13 wt% of indium hydroxide/silver loading on
carbon were used. <b></b></p> | Pui Munn Wong; Teck Hock Lim; Joon Ching Juan; Jau Choy Lai | Nanocatalysis - Catalysts & Materials; Nanostructured Materials - Nanoscience | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c747c9337d6c937fe273fc/original/indium-hydroxide-silver-carbon-nanocomposite-synthesis-via-galvanic-reaction-between-in-nanoparticles-and-silver-nitrate-characterization-and-its-photocatalytic-activity.pdf |
60c7560d0f50db6efe39800b | 10.26434/chemrxiv.8299274.v3 | Structure illumination microscopy imaging of lipid vesicles in live bacteria with naphthalimide-appended organometallic complexes | There is a lack of molecular probes for imaging bacteria, in comparison to the array of such tools available for the imaging of mammalian cells. Here, organometallic molecular probes have been developed and assessed for bacterial imaging, designed to have the potential to support multiple imaging modalities. The chemical structure of the probes is designed around a metal-naphthalimide structure. The 4-amino-1,8-naphthalimide moiety, covalently appended through a pyridine ancillary ligand, acts as a luminescent probe for super-resolution microscopy. On the other hand, the metal centre, rhenium(I) or platinum(II) in the current study, enables techniques such as nanoSIMS. While the rhenium(I) complex was not sufficiently stable to be used as probe, the platinum(II) analogue showed good chemical and biological stability. Structured illumination microscopy (SIM) imaging on live <i>Bacillus cereus</i> confirmed the suitability of the probe for super-resolution microscopy. NanoSIMS analysis was used to monitor the uptake of the platinum(II) complex within the bacteria and demonstrate the potential of this chemical architecture to enable multimodal imaging. The successful combination of these two moieties introduces a platform that could lead to a versatile range of multi-functional probes for bacteria.<br /> | Anna Maria Ranieri; Matteo Vezzelli; Kathryn Leslie; Song Huang; Stefano Stagni; Denis Jacquemin; Haibo Jiang; Alysia Hubbard; Luca Rigamonti; Elizabeth Watkin; Mark Ogden; Elizabeth New; Massimiliano Massi | Imaging Agents; Microscopy; Spectroscopy (Organomet.); Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-03-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7560d0f50db6efe39800b/original/structure-illumination-microscopy-imaging-of-lipid-vesicles-in-live-bacteria-with-naphthalimide-appended-organometallic-complexes.pdf |
60c74889469df47d1bf43a4d | 10.26434/chemrxiv.11919093.v1 | C(sp3)-H Fluorination with a Copper(II)/(III) Redox Couple | <p>Despite
the growing interest in the synthesis of fluorinated organic compounds, few
methods are able to incorporate fluoride ion directly into alkyl C-H bonds. Here,
we report the C(sp<sup>3</sup>)-H fluorination reactivity of a formally
copper(III) fluoride complex. The C-H fluorination intermediate, <b>L</b>CuF,
along with its chloride and bromide analogs, <b>L</b>CuCl and <b>L</b>CuBr,
were prepared directly from halide sources with a chemical oxidant and fully
characterized. While all three copper(III) halide complexes capture carbon radicals
efficiently to afford C(sp<sup>3</sup>)-halogen bonds, <b>L</b>CuF is two
orders of magnitude more efficient at hydrogen atom abstraction (HAA) than <b>L</b>CuCl
and <b>L</b>CuBr. Alongside reported kinetic data for other <b>L</b>Cu(III)
species, we established a positive correlation between ligand basicity and the rate
of HAA. The capability of <b>L</b>CuF to perform both hydrogen atom abstraction and radical capture was
leveraged to enable fluorination of allylic and benzylic C-H bonds and α-C-H
bonds of ethers at room temperature.</p> | Jamey Bower; Andrew Cypcar; Brenda Henriquez; S. Chantal E. Stieber; Shiyu Zhang | Bonding; Coordination Chemistry (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-03-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74889469df47d1bf43a4d/original/c-sp3-h-fluorination-with-a-copper-ii-iii-redox-couple.pdf |
645ccb9ffb40f6b3ee670f87 | 10.26434/chemrxiv-2023-5jw30 | Quantum Dynamics of Oblique Vibrational States in the Hénon-Heiles System | In this paper, we study the quantum time evolution of oblique non-stationary vibrational states in a Hénon-Heiles oscillator system with two dissociation channels. The oblique non-stationary states we are interested in are the eigenfunctions of the anharmonic zeroth-order Hamiltonian operator resulting from the transformation to oblique coordinates, which are defined as those coming from non-orthogonal coordinate rotations that express the matrix representation of the second-order Hamiltonian in a block diagonal form characterized by the polyadic quantum number $n = n_1 + n_2$. The survival probabilities calculated show that the oblique non-stationary states evolve within their polyadic group with a high degree of coherence up to the dissociation limits on the short time scale. The degree of coherence is certainly much higher than that exhibited by the local non-stationary states extracted from the conventional orthogonal rotation of the original normal coordinates. We also show that energy exchange between the oblique vibrational modes occurs in a much more regular way than the exchange between the local modes. | Jose Zuniga; Adolfo Bastida; Alberto Requena | Physical Chemistry; Quantum Mechanics | CC BY NC ND 4.0 | CHEMRXIV | 2023-05-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/645ccb9ffb40f6b3ee670f87/original/quantum-dynamics-of-oblique-vibrational-states-in-the-henon-heiles-system.pdf |
61122c34abc9e263eb6a4e62 | 10.26434/chemrxiv-2021-s1dtc | Viscose-derived activated carbons fibers as highly efficient adsorbents for dimethoate removal from water | Extensive use of pesticides resulting in their accumulation in the environment presents a hazard for their non-target species, including humans. Hence, efficient remediation strategies are needed, and adsorption is seen as the most straightforward approach in this sense. We have studied activated carbon fibers (ACFs) derived from viscose fibers impregnated with diammonium hydrogen phosphate (DAHP). By changing the amount of DAHP in the impregnation step, the chemical composition and textural properties of ACFs are effectively tuned, affecting their performance for dimethoate removal from water. The prepared ACFs effectively reduced the toxicity of treated water samples, both deionized water solutions and spiked tap water samples, under batch conditions and in dynamic filtration experiments. Using the results of physicochemical characterization and dimethoate adsorption measurements, multiple linear regression models were made to predict performance towards dimethoate removal from water reliably. These models can be used to quickly screen among larger sets of possible adsorbents and guide the development of novel, highly efficient adsorbents for dimethoate removal from water. | Ana Jocic; Stefan Breitenbach; Danica Bajuk-Bogdanović; Igor Pašti; Christoph Unterweger; Christian Fürst; Tamara Lazarević-Pašti | Materials Science; Earth, Space, and Environmental Chemistry; Carbon-based Materials; Fibers; Environmental Science | CC BY NC 4.0 | CHEMRXIV | 2021-08-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61122c34abc9e263eb6a4e62/original/viscose-derived-activated-carbons-fibers-as-highly-efficient-adsorbents-for-dimethoate-removal-from-water.pdf |
60c747c4bb8c1a03543dab00 | 10.26434/chemrxiv.11778882.v1 | Predicting Core Level Photoelectron Spectra of Amino Acids Using Density Functional Theory | <div>Core level photoelectron spectroscopy is a widely used technique to study amino acids. Interpretation of the individual contributions from functional groups and their local chemical environments to overall spectra requires both high-resolution reference spectra and theoretical insights, for example from density functional theory calculations. This is a particular challenge for crystalline amino acids due to the lack of experimental data and the limitation of previous calculations to gas phase molecules. </div><div>Here, a state of the art multiresolution approach is used for high precision gas phase calculations and to validate core hole pseudopotentials for plane-wave calculations. This powerful combination of complementary numerical techniques provides a framework for accurate ΔSCF calculations for molecules and solids in systematic basis sets. It is used to successfully predict C and O 1<i>s</i> core level spectra of glycine, alanine and serine and identify chemical state contributions to experimental spectra of crystalline amino acids.</div> | Jo Pi; Martina Stella; Nathalie Fernando; Aaron Lam; Anna Regoutz; Laura Ratcliff | Spectroscopy (Anal. Chem.); Computational Chemistry and Modeling; Quantum Mechanics; Radiation | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c747c4bb8c1a03543dab00/original/predicting-core-level-photoelectron-spectra-of-amino-acids-using-density-functional-theory.pdf |
60c73e9b567dfe1933ec3856 | 10.26434/chemrxiv.7067669.v1 | Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation | We report a six coordinate DyIII single-molecule magnet<br />(SMM) with an energy barrier of 1110 K for thermal relaxation of<br />magnetization. The sample shows no retention of magnetization<br />even at 2 K and this led us to find a good correlation between the<br />blocking temperature and the Raman relaxation regime for SMMs.<br />The key parameter is the relaxation time (𝜏<sub>switch</sub>) at the point where<br />the Raman relaxation mechanism becomes more important than<br />Orbach. | Marcus
J. Giansiracusa; Andreas Kostopoulos; George F. S. Whitehead; David Collison; Floriana Tuna; Richard Winpenny; Nicholas Chilton | Coordination Chemistry (Inorg.); Lanthanides and Actinides; Magnetism | CC BY NC ND 4.0 | CHEMRXIV | 2018-09-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e9b567dfe1933ec3856/original/correlating-blocking-temperatures-in-single-molecule-magnets-with-raman-relaxation.pdf |
652669e9bda59ceb9a552eef | 10.26434/chemrxiv-2023-0wzz0 | Diastereoselective self-assembly of low-symmetry PdnL2n nanocages through coordination-sphere engineering | Metal-organic cages (MOCs) are popular host architectures assembled from ligands and metal ions/nodes. Assembling structurally complex, low-symmetry MOCs with anisotropic cavities can be limited by the formation of statistical isomeric libraries. We set out to investigate the use of primary coordination-sphere engineering (CSE) to bias diastereoselectivity within homo- and heteroleptic PdnL2n cages. Unexpected differences in stereoselectivity between alternative donor groups led us to recognise the significant impact of the second coordination sphere on isomer stabilities. From this, molecular-level insight into the origins of the diastereoselectivity was gained, highlighting the importance of both host-guest and host-solvent interactions, in addition to ligand design. This detailed understanding allows precision engineering of low-symmetry MOC assemblies without wholesale redesign of the ligand framework, and fundamentally provides a theoretical scaffold for the development of stimuli-responsive, shape-shifting MOCs. | Paulina Molinska; Andrew Tarzia; Louise Male; Kim Jelfs; James Lewis | Inorganic Chemistry; Coordination Chemistry (Inorg.); Supramolecular Chemistry (Inorg.); Transition Metal Complexes (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2023-10-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/652669e9bda59ceb9a552eef/original/diastereoselective-self-assembly-of-low-symmetry-pdn-l2n-nanocages-through-coordination-sphere-engineering.pdf |
65a1185466c1381729487c90 | 10.26434/chemrxiv-2024-4gf9b | Machine learning approaches in predicting allosteric sites | Allosteric regulation is a fundamental biological mechanism that can control critical cellular processes
via allosteric modulator binding to protein distal functional sites. The advantages of allosteric
modulators over orthosteric ones have sparked the development of numerous computational
approaches, such as the identification of allosteric binding sites, to facilitate allosteric drug discovery.
Building on the success of Machine Learning (ML) models for solving complex problems in biology and
chemistry, several ML models for predicting allosteric sites have been developed. In this review, we
provide an overview of these models and discuss future perspectives powered by the field of Artificial
Intelligence such as protein Language Models. | Francho Nerín-Fonz; Zoe Cournia | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Bioinformatics and Computational Biology; Computational Chemistry and Modeling; Artificial Intelligence | CC BY NC ND 4.0 | CHEMRXIV | 2024-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65a1185466c1381729487c90/original/machine-learning-approaches-in-predicting-allosteric-sites.pdf |
60c752f1337d6c65ffe287d8 | 10.26434/chemrxiv.13345163.v1 | Response to Comment on “Boosted Molecular Mobility During Common Chemical Reactions” | <h2>Günther et al. report that their control experiment using randomized magnetic field gradient sequences disagreed with findings we had reported using linear gradients. However, we
show that measurements in our laboratory are consistent using both methods.<br /></h2> | huan wang; Myeonggon Park; Ruoyu Dong; junyoung kim; Yoon-Kyoung Cho; tsvi tlusty; steve granick | Chemical Kinetics; Transport phenomena (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-12-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c752f1337d6c65ffe287d8/original/response-to-comment-on-boosted-molecular-mobility-during-common-chemical-reactions.pdf |
60c74f179abda2ff7ff8d79d | 10.26434/chemrxiv.12846050.v1 | Alloy CsCdxPb1-xBr3 Perovskite Nanocrystals: The Role of Surface Passivation in Preserving Composition and Blue Emission | Various strategies have been proposed to engineer the
band gap of metal halide perovskite nanocrystals (NCs) while preserving their structure
and composition and thus ensuring spectral stability of the emission color. An aspect that has only been marginally
investigated is how the type of surface passivation influences the structural/color
stability of AMX<sub>3</sub> perovskite NCs composed of two different M<sup>2+</sup> cations. Here, we report the synthesis of blue-emitting
Cs-oleate capped CsCd<sub>x</sub>Pb<sub>1-x</sub>Br<sub>3</sub> NCs, which
exhibit a cubic perovskite phase containing also Cd-rich domains of Ruddlesden-Popper phases (RP- phases). The RP domains spontaneously transforms into pure orthorhombic perovskite ones
upon NC ageing and the
emission color of the NCs shifts from blue to green over days. On the other hand, post-synthesis ligand
exchange with various Cs-carboxylate
or ammonium bromide salts, right after NC
synthesis, provides monocrystalline
NCs with cubic phase, highlighting the metastability of the RP domains. When
the NCs are treated with Cs-carboxylates (including Cs-oleate), most of the Cd<sup>2+</sup>
ions are expelled from the NCs, the NCs’ phase evolves from cubic to
orthorhombic and their emission color changes from blue to green. Instead, when the NCs are
coated with ammonium bromides, the
loss of Cd<sup>2+</sup> ions is
suppressed and
the NCs tend to retain their blue emission (both in colloidal dispersions and
in electroluminescent devices), as
well as their cubic phase, over time. The improved
compositional and structural stability in these latter cases is ascribed to the
saturation of surface vacancies, which may act as channels for the expulsion of
Cd<sup>2+</sup> ions from the NCs. | Muhammad Imran; Julien Ramade; Francesco Di Stasio; Manuela De Franco; Joka Buha; Sandra Van Aert; Luca Goldoni; Simone Lauciello; Mirko Prato; Ivan Infante; Sara Bals; Liberato Manna | Nanostructured Materials - Nanoscience | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74f179abda2ff7ff8d79d/original/alloy-cs-cdx-pb1-x-br3-perovskite-nanocrystals-the-role-of-surface-passivation-in-preserving-composition-and-blue-emission.pdf |
60c756f1f96a000435288ba1 | 10.26434/chemrxiv.14346920.v1 | Kernel Methods for Predicting Yields of Chemical Reactions | The use of machine learning methods for the prediction of reaction yield is an emerging area.
We demonstrate the applicability of support vector regression (SVR) for predicting reaction yields,
using combinatorial data. Molecular descriptors used in regression tasks related to chemical reac?tivity have often been based on time-consuming, computationally demanding quantum chemical
calculations, usually density functional theory. Structure-based descriptors (molecular fingerprints
and molecular graphs) are quicker and easier to calculate, and are applicable to any molecule.
In this study, SVR models built on structure-based descriptors were compared to models built on
quantum chemical descriptors. The models were evaluated along the dimension of each reaction
component in a set of Buchwald-Hartwig amination reactions. The structure-based SVR models
out-performed the quantum chemical SVR models, along the dimension of each reaction compo?nent. The applicability of the models was assessed with respect to similarity to training. Prospec?tive predictions of unseen Buchwald-Hartwig reactions are presented for synthetic assessment, to
validate the generalisability of the models, with particular interest along the aryl halide dimension. | Alexe Haywood; Joseph Redshaw; Magnus Hanson-Heine; Adam Taylor; Alex Brown; Andy Mason; Thomas Gaertner; Jonathan Hirst | Machine Learning; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c756f1f96a000435288ba1/original/kernel-methods-for-predicting-yields-of-chemical-reactions.pdf |
60fb1766537d1081967f1497 | 10.26434/chemrxiv-2021-3jdm1 | Anisotropic Foams Via Frontal Polymerization | The properties of foams, an important class of cellular solids, are most sensitive to the volume fraction and openness of its elementary compartments; size, shape, orientation, and the interconnectedness of the cells are other important design attributes. Control of these morphological traits would allow the tailored fabrication of useful materials including highly porous solids, anisotropic heat conductors, tough composites, among others. While approaches like ice templating has produced foams with elongated cells, there is a need for rapid, versatile, and energy efficient methods that also control the local order and macroscopic alignment of cellular elements. Here we describe a fast and convenient method to obtain anisotropic structural foams using frontal polymerization. We fabricated foams by curing mixtures of dicyclopentadiene and a physical blowing agent via frontal ring opening metathesis polymerization (FROMP). The materials were characterized using micro-computed tomography and an image analysis protocol to quantify morphological characteristics including volume fraction and anisotropy. The cellular structure, porosity, and hardness of the foams changed with blowing agent, concentration, and resin viscosity. Moreover, we used a full factorial combination of variables to correlate each parameter with the structure of the obtained foams. We found a strong correlation between the resin viscosity and the foam’s cellular structure. Furthermore, a specific combination of input parameters controlled the transitions from (i) isotropic to anisotropic cellular structures, (ii) porous to non-porous, and (iii) soft to hard foams. Our results demonstrate the controlled production of foams with specific morphologies using the simple and efficient method of frontal polymerization. This work shows promise for creating foams with aligned cellular structures that allow anisotropic mass and energy transport properties in high performance structural solids. | Diego M. Alzate-Sanchez; Morgan M. Cencer; Michael Rogalski; Mariana Kersh; Nancy Sottos; Jeffrey S. Moore | Materials Science; Carbon-based Materials; Materials Processing; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2021-07-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60fb1766537d1081967f1497/original/anisotropic-foams-via-frontal-polymerization.pdf |
63324981e6150214f727ce9a | 10.26434/chemrxiv-2022-f2r01 | Recharging Upconversion: Revealing Rubrene’s Replacement | One of the major limitations of solid-state perovskite-sensitized photon upconversion to date is that the only annihilator successfully paired with the perovskite sensitizer has been rubrene, raising the question of whether this approach of triplet sensitization is universal or limited in scope. Additionally, the inherent energetic mismatch between the perovskite bandgap and the rubrene triplet energy has restricted the apparent anti-Stokes shift achievable in the upconversion process. To increase the apparent anti-Stokes shift for upconversion processes, anthracene derivates are of particular interest due to their deeper highest occupied molecular orbital levels and higher triplet energies. Here, we demonstrate successful sensitization of the triplet level of 1-chloro-9,10-bis(phenylethynyl)anthracene using the established formamidinium methylammonium lead triiodide perovskite, resulting in upconverted emission at 550 nm under 780 nm excitation. We draw a direct comparison to rubrene to unravel the underlying differences in the upconversion processes. | Colette Sullivan; Lea Nienhaus | Physical Chemistry; Energy; Interfaces; Photochemistry (Physical Chem.); Spectroscopy (Physical Chem.); Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-10-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63324981e6150214f727ce9a/original/recharging-upconversion-revealing-rubrene-s-replacement.pdf |
626821fbef2adef58f3e17ea | 10.26434/chemrxiv-2022-34klf | Hanging-droplet sample preparation improves sensitivity of spatial proteomics | Spatial proteomics holds great promise for revealing tissue heterogeneity in both physiological and pathological conditions. However, one significant limitation of most spatial proteomics workflows is the requirement of large sample amounts that blurs cell-type-specific or microstructure-specific information. In this study, we developed an improved sample preparation approach for spatial proteomics and integrated it with our previously-established laser capture microdissection (LCM) and microfluidics sample processing platform. Specifically, we developed a hanging drop (HD) method to improve the sample recovery by positioning a nanowell chip upside-down during protein extraction and tryptic digestion steps. Compared with the commonly-used sitting-drop method, the HD method keeps the tissue voxel away from the container surface, and thus improves the accessibility of the extraction/digestion buffer to tissue sample. The HD method can increase the MS signal by 7 fold, leading to a 66% increase in the number of identified proteins. An average of 721, 1489, and 2521 proteins can be quantitatively profiled from laser-dissected 10-µm-thick mouse liver tissue voxels with areas of 0.0025, 0.01, and 0.04 mm2, respectively. The improved system was further validated in the study of cell-type-specific proteomes of mouse uterine tissues. | Yumi Kwon; Paul Piehowski; Rui Zhao; Ryan Sontag; Ronald Moore; Kristin Burnum-Johnson; Richard Smith; Weijun Qian; Ryan Kelly; Ying Zhu | Analytical Chemistry; Mass Spectrometry | CC BY NC ND 4.0 | CHEMRXIV | 2022-04-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/626821fbef2adef58f3e17ea/original/hanging-droplet-sample-preparation-improves-sensitivity-of-spatial-proteomics.pdf |
60c747fb702a9b407e18aebc | 10.26434/chemrxiv.11663805.v2 | Fractional Occupation Numbers and SIC-Scaling Methods with the Fermi-Lowdin Orbital SIC Approach | We derive an alternate expression for the Fermi-Lowdin Orbital Self-Interaction Correction (FLO-SIC) energy gradient and re-visit how the FLO-SIC methodology can be seen as a constrained unitary transformation acting on canonical Kohn-Sham orbitals. We present a new performance and accuracy analysis of the FLO-SIC approach, which we have recently implemented in the massively-parallelized NWChem quantum chemistry software package. Our FLO-SIC implementation has been tested for the prediction of total energies, atomization energies, and ionization potentials of small molecules and relatively large aromatic systems. The ionization potentials of multi-electron systems are calculated with the adaptation of fractional occupation numbers within FLO-SIC. We also carefully examine the possible improvements of these predictions with various SIC scaling methods based on kinetic energy densities and gradients of electronic densities. | Fredy W. Aquino; Ravindra Shinde; Bryan Wong | Computational Chemistry and Modeling; Theory - Computational; Physical and Chemical Properties; Quantum Mechanics; Structure | CC BY NC ND 4.0 | CHEMRXIV | 2020-01-31 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c747fb702a9b407e18aebc/original/fractional-occupation-numbers-and-sic-scaling-methods-with-the-fermi-lowdin-orbital-sic-approach.pdf |
60c748689abda23a03f8ca8c | 10.26434/chemrxiv.11905557.v1 | Mono- Versus Bicyclic Carbene Metal Amide Photoemitters: Which Design Leads to Best Performance? | New
luminescent “carbene-metal-amide” (CMA) Cu, Ag and Au complexes based on
monocyclic (C6) or bicyclic six-ring (BIC6) cyclic (alkyl)(amino)carbene
ligands illustrates the effects of LUMO energy stabilization, conformational
flexibility and excited state energy on the photoemission properties, leading
to near-quantitative quantum yields, short excited state lifetimes Cu > Au >
Ag down to 0.5 µs and high radiative rates of 10<sup>6</sup> s<sup>–1</sup>. | Florian Chotard; Vasily Sivchik; Mikko Linnolahti; Manfred Bochmann; Alexander Romanov | Optical Materials; Transition Metal Complexes (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c748689abda23a03f8ca8c/original/mono-versus-bicyclic-carbene-metal-amide-photoemitters-which-design-leads-to-best-performance.pdf |
64e9c24e79853bbd78762cbf | 10.26434/chemrxiv-2023-gx8rc | Bioorthogonal Photocatalytic Profiling of Mitochondrial Proteomes from Primary Living Samples | In situ profiling of subcellular proteomic networks in primary and living systems, such as primary cells derived from native tissues or clinic samples, is crucial for the understanding of life processes and diseases, yet challenging for the current proximity labeling methods (e.g., BioID, APEX) due to their necessity of genetic engineering. Here we report CAT-S, a new-generation bioorthogonal photocatalytic chemistry-enabled proximity labeling method, that extends proximity labeling to a wide range of primary living samples for in situ profiling of subcellular proteomes. Powered by the newly introduced thioQM labeling warhead and targeted bioorthogonal photocatalytic decaging chemistry, CAT-S enables in situ labeling of mitochondrial proteins in living cells with high efficiency and specificity. We applied CAT-S to distinct cell cultures, mouse tissues (kidney and spleen) as well as primary T cells from human blood, portraying the mitochondrial proteomic characteristics for various primary living samples, and unveiled a set of hidden mitochondrial proteins in human proteome. Furthermore, CAT-S allows quantitative analysis of the in situ proteomic perturbations on dysfunctional tissue samples, exampled by the comparative proteomics of diabetic mouse kidneys, and revealed the alterations of lipid metabolism machinery that drive the disease progression. Given the unique advantages of non-genetic operation, generality, efficiency as well as high spatiotemporal resolution, we envision that CAT-S may open new avenues as a proximity labeling strategy for in situ investigation of the native-state subcellular proteomic landscape of primary living samples that are otherwise inaccessible, promoting our understanding of the molecular mechanisms underlying biological and pathological processes. | Ziqi Liu; Fuhu Guo; Yufan Zhu; Shengnan Qin; Yuchen Hou; Feng Lin; Haotian Guo; Peng Chen; Xinyuan Fan | Biological and Medicinal Chemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64e9c24e79853bbd78762cbf/original/bioorthogonal-photocatalytic-profiling-of-mitochondrial-proteomes-from-primary-living-samples.pdf |
62f3de6ba014478353b2db96 | 10.26434/chemrxiv-2022-3t0hc | Interfacial connections between organic perovskite/n+ silicon/catalyst that allow integration of solar cell and catalyst for hydrogen evolution from water | The rapidly increasing solar conversion efficiency (PCE) of hybrid organic-inorganic perovskite (HOIP) thin-film semiconductors has triggered interest in their use for direct solar-driven water splitting to produce hydrogen. However, application of these low-cost, electronic-structure-tunable HOIP tandem photoabsorbers has been hindered by the instability of the photovoltaic-catalyst-electrolyte (PV+E) interfaces. Here, photolytic water splitting is demonstrated using an integrated configuration consisting of an HOIP/n+silicon single junction photoabsorber and a platinum (Pt) thin film catalyst. An extended electrochemical (EC) lifetime in alkaline media is achieved using titanium nitride (TiN) on both sides of the Si support to eliminate formation of insulating silicon oxide, and as an effective diffusion barrier to allow high-temperature annealing of the catalyst/TiO2-protected-n+silicon interface necessary to retard electrolytic corrosion. Halide composition was examined in the (Cs1-xFAx)PbI3 system with a bandgap suitable for tandem operation. A fill factor (FF) of 72.5% was achieved using a Spiro-OMeTAD-hole-transport-layer (HTL)-based HOIP/n+Si solar cell, and a high photocurrent density of -15.9 mA/cm2 (at 0V vs reversible hydrogen electrode) was attained for the HOIP/n+Si/Pt photocathode in 1M NaOH under simulated one-sun illumination. While this thin-film design creates stable interfaces, the intrinsic photo- and electro-degradation of the HOIP photoabsorber remains the main obstacle for future HOIP/Si tandem PEC devices. | Hengfei Gu; Fei Zhang; Shinjae Hwang; Anders B. Laursen; Xin Liu; So Yeon Park; Mengjin Yang; Rosemary C. Bramante; Hussein Hijazi; Leila Kasaei; Leonard C. Feldman; Yao-Wen Yeh; Philip E. Batson; Bryon W. Larson; Mengjun Li; Yifei Li; Kai Zhu; Eric Garfunkel; G. Charles Dismukes | Catalysis; Energy; Electrocatalysis; Photocatalysis; Photovoltaics; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-08-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62f3de6ba014478353b2db96/original/interfacial-connections-between-organic-perovskite-n-silicon-catalyst-that-allow-integration-of-solar-cell-and-catalyst-for-hydrogen-evolution-from-water.pdf |
66c57b36f3f4b052908f67c5 | 10.26434/chemrxiv-2024-qmfsc | Evaluating Postharvest Washing Methods for Micro-Nanoplastic Removal from Edible Vegetable Leaves | Micro and nano-plastics (MNPs) have become a significant contamination concern in various ecosystems. In agriculture, they contaminate edible plants through different sources, such as irrigation and air deposition, threatening food safety and human health. It is uncertain whether post-harvest cleaning methods can effectively remove MNPs from the surface of edible plants. This study used confocal Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS) to assess the efficacy of household and industrial postharvest washing methods in removing MNPs from vegetable leaf surfaces. In particular, the cleaning techniques included tap water washing, vegetable detergent washing, and sonication cleaning. The plastic particles tested included 42 µm polystyrene (PS), 6 µm polymethyl methacrylate (PMMA), and 61 nm PS. In evaluating cleaning methods to remove MNPs from basil leaves, the tap water washing method demonstrated high removal efficacy for 42 µm PS (93.1%) but lower efficacy for 6 µm PMMA (51.6%). Vegetable detergent was the most effective method for PMMA removal (73.3%). The sonication method exhibited the highest removal efficacy of 59.8% among the three washing methods for removing 61 nm PS. This is the first time that the efficacies of common washing methods to remove MNPs from fresh produce were evaluated and compared using confocal Raman spectroscopy and SERS. The research offers critical insights and approaches for assessing the removal efficacy of commonly used washing techniques in decontaminating MNPs from fresh produce. The findings highlight the need to develop more effective washing methods to enhance MNPs removal in the future. | Mingjiu Liu; Anupam Das; Lynn Terry; Huiyuan Guo | Earth, Space, and Environmental Chemistry; Agriculture and Food Chemistry; Environmental Science; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66c57b36f3f4b052908f67c5/original/evaluating-postharvest-washing-methods-for-micro-nanoplastic-removal-from-edible-vegetable-leaves.pdf |
65cf7145e9ebbb4db9818f8e | 10.26434/chemrxiv-2024-jxls8 | High-bandwidth low-current measurement system for automated and scalable probing of tunnel junctions in liquids | Tunnel junctions have long been used to immobilize and study the electronic transport properties of single molecules. The sensitivity of tunneling currents to entities in the tunneling gap has generated interest in developing electronic biosensors with single molecule resolution. Tunnel junctions can, for example, be used for sensing bound or unbound DNA, RNA, amino acids, and proteins in liquids. However, manufacturing technologies for on-chip integrated arrays of tunnel junction sensors are still in their infancy, and scalable measurement strategies that allow the measurement of large numbers of tunneling junctions are required to facilitate progress. Here, we describe an experimental setup to perform scalable, high bandwidth (> 10 kHz) measurements of low currents (pA–nA) in arrays of on-chip integrated tunnel junctions immersed in various liquid media. Leveraging a commercially available compact 100 kHz bandwidth low-current measurement instrument, we developed a custom two-terminal probe on which the amplifier is directly mounted to decrease parasitic probe capacitances to sub-pF levels. We also integrated a motorized 3-axis stage, which could be powered down using software control, inside the Faraday cage of the setup. This enabled automated data acquisition on arrays of tunnel junctions without worsening the noise floor despite being inside the Faraday cage. A deliberately positioned air gap in the fluidic path ensured liquid perfusion to the chip from outside the Faraday cage without coupling in additional noise. We demonstrated the performance of our setup using rapid current switching observed in electromigrated gold tunnel junctions immersed in deionized water. Our measurement setup and findings will contribute to developing the emerging field of tunnel junction sensors and can be readily extended towards higher bandwidth sensing, as well as to other types of electronic single molecule sensors. | Shyamprasad N. Raja; Saumey Jain; Javier Kipen; Joakim Jaldén; Göran Stemme; Anna Herland; Frank Niklaus | Nanoscience; Nanodevices | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65cf7145e9ebbb4db9818f8e/original/high-bandwidth-low-current-measurement-system-for-automated-and-scalable-probing-of-tunnel-junctions-in-liquids.pdf |
62a0a47bb749a056c49c5788 | 10.26434/chemrxiv-2022-gwvg4-v2 | One-shot trajectory learning of open
quantum systems dynamics | Nonadiabatic quantum dynamics are important for understanding light-harvesting processes, but their propagation with traditional methods can be rather expensive. Here we present a one-shot trajectory learning approach that allows to directly make ultra-fast prediction of the entire trajectory of the reduced density matrix for a new set of such simulation parameters as temperature and reorganization energy. The whole 10ps long propagation takes 70 milliseconds as we demonstrate on the comparatively large quantum system, the Fenna–Matthews–Olsen (FMO) complex. Our approach
also significantly reduces time and memory requirements for training. | ARIF ULLAH; Pavlo O. Dral | Theoretical and Computational Chemistry; Machine Learning | CC BY 4.0 | CHEMRXIV | 2022-06-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62a0a47bb749a056c49c5788/original/one-shot-trajectory-learning-of-open-quantum-systems-dynamics.pdf |
66e9dea7cec5d6c1425e1ab7 | 10.26434/chemrxiv-2024-dk7v6 | Chemical composition and antibacterial activity of the essential oil of Coreopsis lanceolata leaves | We have evaluated the antibacterial activity of the essential oil of the leaves of Coreopsis lanceolata (CL-EO) collected in southeastern Brazil. against a representative panel of cariogenic bacteria. The activity was evaluated in terms of its Minimum Inhibitory Concentration (MIC) values. CL-EO displays moderate activity against Streptococcus mutans, S. sanguinis, S. salivarus, S. sobrinus, Lactobacillus paracasei, and Enterococcus faecalis (MIC = 1000 µg/mL) and strong activity against S. mitis (MIC = 500 µg/mL). We have identified 1,11-tridecadiene-3,5,7,9-tetrayne (48.9%), β-bisabolene (22.8%), germacrene D (9.2%), and globulol (4.6%) as the major compounds in CL-EO. This is the first report on the chemical composition of the essential oil obtained from C. lanceolata leaves. | Richard Lima; Ana Carla Colli; Sara Souza; Milton Groppo; Carlos Martins; Antônio Crotti | Biological and Medicinal Chemistry; Organic Chemistry; Natural Products; Drug Discovery and Drug Delivery Systems; Microbiology | CC BY NC ND 4.0 | CHEMRXIV | 2024-09-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66e9dea7cec5d6c1425e1ab7/original/chemical-composition-and-antibacterial-activity-of-the-essential-oil-of-coreopsis-lanceolata-leaves.pdf |
6260ace8bdc9c2bdb2dd2be7 | 10.26434/chemrxiv-2022-t1q59 | Extreme Extensibility in Physically Crosslinked Nanocomposite Hydrogels Leveraging
Dynamic Polymer-Nanoparticle Interactions | Designing yield stress fluids to exhibit desired functional properties is an integral challenge in many applications such as 3D printing, drilling, food formulation, fiber spinning, adhesives and injectable biomaterials. Extensibility in particular has been found to be a highly beneficial characteristic for materials in these applications; however, few highly extensible, high water content materials have been reported to date. Herein we engineer a class of high water content nanocomposite hydrogel materials leveraging multivalent, non-covalent, polymer-nanoparticle (PNP) interactions between modified cellulose polymers and biodegradable nanoparticles. We show that modulation of the chemical composition of the PNP hydrogels controls the dynamic crosslinking interactions within the polymer network and directly impacts yielding and viscoelastic
responses. These materials can be engineered to stretch up to 2000% strain and occupy an unprecedented property regime for extensible yield stress fluids. Moreover, a dimensional analysis of the relationships between extensibility and the relaxation and recovery timescales of these nanocomposite hydrogels uncovers generalizable design criteria that will be critical for future development of extensible materials. | Abigail K. Grosskopf; Joseph L. Mann; Julie Baillet; Hector Lopez Hernandez; Anton A. A. Autzen; Anthony C. Yu; Eric A. Appel | Materials Science; Polymer Science; Nanoscience; Biocompatible Materials; Cellulosic materials; Hydrogels | CC BY NC 4.0 | CHEMRXIV | 2022-04-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6260ace8bdc9c2bdb2dd2be7/original/extreme-extensibility-in-physically-crosslinked-nanocomposite-hydrogels-leveraging-dynamic-polymer-nanoparticle-interactions.pdf |
60c74abd842e6571bcdb2fd5 | 10.26434/chemrxiv.12248786.v1 | Effect of Solvent Quality on the Phase Behavior of Polyelectrolyte Complexes | <div>
<div>
<div>
<p>The role of polyelectrolyte-solvent interactions, among other non-Coulomb interactions, in dictating the
thermodynamics and kinetics of polyelectrolyte complexation is prominent, yet sparingly studied. In this article, we present
systematic comparisons of the binodal phase behavior of polyelectrolyte complexes (PECs) comprising polyelectrolytes with
varying quality of backbone-solvent interactions. Experimental phase diagrams of polyelectrolyte complexes with either a peptide
or an aliphatic backbone highlight the influence of backbone chemistry on the composition of complexes and their salt resistance.
Corresponding theoretical phase diagrams, obtained from a framework combining the random phase approximation and Flory-
Huggins approach, reveal a transition from closed phase boundaries with confined two-phase regions for PECs in good solvents
to open phase boundaries, wherein two-phase systems are predicted to exist even at very high salt concentrations, for PECs in
poor solvents. These predictions compare fittingly with experimental observations of low salt resistance (~1 M NaCl) of PECs
comprising hydrophilic polyelectrolytes and persistence of complexes, stabilized by short-range hydrophobic interactions, even
at very high salt concentrations (~6 M NaCl) for PECs comprising hydrophobic polyelectrolytes.
</p>
</div>
</div>
</div> | Lu Li; Artem M. Rumyantsev; Samanvaya Srivastava; Siqi Meng; Juan de Pablo; Matthew Tirrell | Polyelectrolytes - Materials; Polyelectrolytes - Polymers; Polymers | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74abd842e6571bcdb2fd5/original/effect-of-solvent-quality-on-the-phase-behavior-of-polyelectrolyte-complexes.pdf |
64eb2db63fdae147faf1e1d3 | 10.26434/chemrxiv-2023-kzqcg | Near-Complete Destruction of PFAS in Aqueous Film-Forming Foam (AFFF) by Integrated Photo-Electrochemical Processes | Per- and polyfluoroalkyl substances (PFAS) are highly recalcitrant pollutants in the water environment worldwide. Aqueous film-foaming foam (AFFF) for fire-fighting is a major source of PFAS pollution. However, complete defluorination (i.e., cleaving all C−F bonds into F− ions) of PFAS by a non-thermal technology is rare. The destruction of the PFAS mixture in the complex organic matrix of AFFF is even more challenging. In this study, we designed and demonstrated a UV/sulfite−electrochemical oxidation (UV/S−EO) process. The tandem UV/S−EO leverages the complementary advantages of UV/S and EO modules in (i) PFAS transformation mechanism and (ii) engineering process design (e.g., foaming control, chemical dosage, and energy consumption). At ambient temperature and pressure, The UV/S−EO realized near-complete defluorination and mineralization of most PFAS and organics in AFFF (50−500x diluted, containing up to 200 mg L−1 organic fluorine and >4000 mg L−1 organic carbon). This work highlights the integration of molecular-level insight and engineering design toward solving major challenges of AFFF water pollution and stockpile disposal. | Yunqiao Guan; Zekun Liu; Nanyang Yang; Shasha Yang; Estefanny Quispe-Cardenas; Jinyong Liu; Yang Yang | Earth, Space, and Environmental Chemistry; Environmental Science; Hydrology and Water Chemistry; Wastes | CC BY 4.0 | CHEMRXIV | 2023-08-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64eb2db63fdae147faf1e1d3/original/near-complete-destruction-of-pfas-in-aqueous-film-forming-foam-afff-by-integrated-photo-electrochemical-processes.pdf |
673325c37be152b1d0d34eaa | 10.26434/chemrxiv-2024-v0vcg | Direct Edge-Functionalization of Corannulene-Coronene Hybrid Nanographenes | For more than a century, electrophilic aromatic substitution reactions have been central to the construction of a rich variety of organic molecules useful in all aspects of human life. Typically, small aromatic nuclei such as benzene provide an ideal substrate. An increase in the number of annulated aromatic rings enhances the number of potential reactive sites and frequently results into complex product mixtures. Thus, nanographenes, with a relatively large aromatic system, are seldom selective in their substitution positions. Moreover, nanographene substrates with scope for multiple substitution reactions and patterns remains rare. Herein, we demonstrate that a curved aromatic system based on a corannulene-coronene hybrid structure comprising of 48 conjugated sp2-carbon atoms allows for direct and regioselective edge-functionalization through bromination, nitration, formylation, and Friedel-Crafts acylation in good yields. The post-synthetically installed functional groups can be modified through versatile organic chemistry transformations including (mechanochemical) Suzuki-Miyaura, Sonogashira-Hagihara, and Buchwald-Hartwig amination reactions. Furthermore, the substitutions can be carried out in a sequential manner to yield hetero-functional structures. The edge-functionalization strategy enables modular access to nanostructures with appealing properties, such as strong fluorescence emission in the visible and the near-infrared regions (475-900 nm) with record Stokes shifts (>300 nm), at an exceptionally small carbon footprint (C48). | Jovana Stanojkovic; Natalia Terenti; Mihaiela Stuparu | Organic Chemistry; Nanoscience; Organic Synthesis and Reactions; Nanostructured Materials - Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-11-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/673325c37be152b1d0d34eaa/original/direct-edge-functionalization-of-corannulene-coronene-hybrid-nanographenes.pdf |
6123bf54b136d6f59e0d59ac | 10.26434/chemrxiv-2021-7520x-v2 | Prediction of Interfacial Properties of High-Performance Polymers and Flattened CNT-Reinforced Composites using Molecular Dynamics | The next generation of ultra-high strength composites for structural components of vehicles for manned missions to deep space will likely incorporate flattened carbon nanotubes (flCNTs). With a wide range of high-performance polymers to choose from as the matrix component, efficient and accurate computational modeling can be used to efficiently down-select compatible resins, drive the design of these composites by predicting interface behavior, and provide critical physical insight into the flCNT/polymer interface. In this study, molecular dynamics simulation is used to predict the interaction energy, frictional sliding resistance, and mechanical binding of flCNT/polymer interfaces for epoxy, bismaleimide (BMI), and benzoxazine high-performance resins. The results indicate that the BMI has stronger interfacial interaction and transverse tension binding with flCNT interfaces, while the benzoxazine demonstrates the strongest levels of interfacial friction resistance. Comparison of these results with similar results from the literature for other high-performance resins indicates that BMI demonstrates the best overall compatibility with flCNTs for use in high-performance structural composites. | Prathamesh Deshpande; Matthew Radue; Prashik Gaikwad; Swapnil Bamane; Sagar Patil; William Pisani; Gregory Odegard | Theoretical and Computational Chemistry; Materials Science; Polymer Science; Composites; Computational Chemistry and Modeling | CC BY 4.0 | CHEMRXIV | 2021-08-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6123bf54b136d6f59e0d59ac/original/prediction-of-interfacial-properties-of-high-performance-polymers-and-flattened-cnt-reinforced-composites-using-molecular-dynamics.pdf |
60c74da6337d6c819ae27e0d | 10.26434/chemrxiv.12588266.v2 | Ag(I)/TiO2-Photocatalyzed N-Methylation of Amino Acids with Methanol | <div><div><div><p>Silver(I)-loaded titanium dioxide (AgNO3/TiO2) catalyzes the direct N-methylation of amino acids with methanol under irradiation with UV light. This method produces a variety of N-methyl and N,N-dimethyl amino acids with retention of their optical purity.</p></div></div></div> | Yuna Morioka; Ivven Huang; Susumu Saito; Hiroshi Naka | Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Photochemistry (Org.); Food; Heterogeneous Catalysis; Photocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-07-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74da6337d6c819ae27e0d/original/ag-i-ti-o2-photocatalyzed-n-methylation-of-amino-acids-with-methanol.pdf |
66fee87bcec5d6c142103149 | 10.26434/chemrxiv-2024-q844g | A Framework for Optimizing Continuous Methane Monitoring System Configuration for Minimal Blind Time: Application and Insights from over 100 Operational Oil & Gas Facilities | Continuous monitoring systems (CMS) that utilize fixed-point sensors provide high temporal resolution point-in-space measurements of ambient methane concentration. This study introduces a modular framework for optimizing CMS configurations, encompassing sensor density (number of sensors) and near-optimal placement. By introducing a metric called ‘blind time’, this study attempts to capture periods where the network fails to make detections that could satisfy the regulatory requirement of quantifying emissions every 12 hours. This framework is then applied to 124 operational oil and gas production facilities with a wide variety of site characteristics and meteorological conditions. This study determines a representative blind time for near-optimum CMS configurations for operational facilities and then investigates the impact of different sensor network densities on the performance of the CMS. The results demonstrate that 3-sensor networks, when placed in near-optimum arrangements, can achieve blind time of less than 10% and a mean time to detection of approximately 82 minutes. | Noah Metzger; Ali Lashgari; Umair Ismail; David Ball; Nathan Eichenlaub | Earth, Space, and Environmental Chemistry | CC BY NC 4.0 | CHEMRXIV | 2024-10-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66fee87bcec5d6c142103149/original/a-framework-for-optimizing-continuous-methane-monitoring-system-configuration-for-minimal-blind-time-application-and-insights-from-over-100-operational-oil-gas-facilities.pdf |
60c7504c0f50dba206397561 | 10.26434/chemrxiv.13015994.v1 | H2 Formation Holds the Key to Opening the Fe Coordination Sites of Nitrogenase FeMo-cofactor for Dinitrogen Activation | The
present quantum-mechanical and molecular-mechanics study reveals the crucial
roles of H<sub>2</sub> formation, of H<sub>2</sub>S shift and of N<sub>2</sub>
bond expansion in the nitrogenase process of the reduction of N<sub>2</sub> to <a href="https://en.wikipedia.org/wiki/Ammonia">NH<sub>3</sub></a>. Proton and electron transfers to the Fe(C@Fe<sub>6</sub>S<sub>9</sub>)Mo
unit of the FeMo-co complex weaken the Fe-S and Fe-H bonds and expose the <b>Fe</b> coordination sites, coupled with energy
release due to H<sub>2</sub> generation. Thereby the two sites <b>Fe2</b> and <b>Fe6</b> become prepared for stronger N<sub>2</sub> adsorption, expanding
and attenuating the ǀN≡Nǀ bond.
After subsequent detachment of H<sub>2</sub>S from its Fe binding site into a holding site of the
rearranged protein residue, the <b>Fe6</b>
site becomes completely unfolded, and the N<sub>2</sub> triple bond becomes completely
activated to an ‑<u>N</u>=<u>N</u>- double bond for easy subsequent
hydrogenation to NH<sub>3</sub>. We explain in particular, why the obligatory H<sub>2</sub>
formation is an essential step in N<sub>2</sub> adsorption and activation | Yong Li; Wan-Lu Li; Jin-Cheng Liu; Jun-Bo Lu; W. H. Eugen Schwarz; Lyudmila
V. Moskaleva; Jun Li | Biocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7504c0f50dba206397561/original/h2-formation-holds-the-key-to-opening-the-fe-coordination-sites-of-nitrogenase-fe-mo-cofactor-for-dinitrogen-activation.pdf |
63a46c0be8047a3e9af22977 | 10.26434/chemrxiv-2022-tcb7t | Solving Response Expressions in the ADC/ISR Framework | We present an implementation for the calculation of molecular response properties using the ADC/ISR approach up to third order. For second order ADC(2), a memory-efficient ansatz avoiding the storage of double excitation amplitudes is investigated. We compare the performance of different numerical algorithms for the solution of the underlying response equations for ADC(2) and show that this memory-efficient ansatz strongly improves the convergence behavior for the investigated algorithms. All routines are implemented in an open-source Python library. | Maximilian Scheurer; Antonia Papapostolou; Thomas Fransson; Patrick Norman; Andreas Dreuw; Dirk Rehn | Theoretical and Computational Chemistry; Theory - Computational | CC BY NC 4.0 | CHEMRXIV | 2022-12-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63a46c0be8047a3e9af22977/original/solving-response-expressions-in-the-adc-isr-framework.pdf |
64cad04b4a3f7d0c0d7df4cc | 10.26434/chemrxiv-2023-2qdvc | Bifunctional Au-Sn-SiO2 catalysts promote the direct upgrading of glycerol to lactates | Valuable alkyl lactates can be obtained from (waste) glycerol, through a two-step process that entails (i) the oxidation to dihydroxyacetone (DHA) and (ii) a rearrangement of DHA with an alcohol. While the latter reaction is effectively catalyzed by Sn-based heterogeneous catalysts, the former reaction can be carried out with Au-based catalysts. The overall process, however, is penalized by a limited selectivity of supported gold nanoparticles in the first reaction, which strongly restrains the overall lactate yield. To avoid transitional purification steps, it appears interesting to run the process as a cascade reaction, in one step, and ideally with bifunctional catalysts. The preparation of such catalysts, however, remains a challenge. Here, bifunctional catalysts are prepared in one step, through a straightforward aerosol-assisted sol-gel route. The catalysts feature small Au nanoparticles (3-4 nm) embedded at the surface of mesoporous Sn-doped silica microspheres. The preparation successfully leads to insert both active sites in their most active forms, and in close proximity. With the bifunctional catalysts, the selectivity for the final product of the cascade reaction (methyl lactate) is higher than the DHA selectivity when only the first reaction is carried out. This highlights a beneficial substrate channeling effect which helps avoiding side reactions. Interestingly, the bifunctional catalysts also markedly outcompeted mechanical mixtures of the corresponding Au- and Sn-based catalysts. Thus, the spatial proximity between the two active sites in bifunctional catalysts is identified as a key to stir the cascade reaction towards high yield. | Margot Van der Verren; Anna Corrias; Vit Vykoukal; Ales Styskalik; Carmela Aprile; Damien P. Debecker | Materials Science; Catalysis; Catalysts; Heterogeneous Catalysis; Nanocatalysis - Reactions & Mechanisms | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64cad04b4a3f7d0c0d7df4cc/original/bifunctional-au-sn-si-o2-catalysts-promote-the-direct-upgrading-of-glycerol-to-lactates.pdf |
6299a762195959994dbf51a4 | 10.26434/chemrxiv-2022-gnwjm | Platform of spectral analysis based on a tunable coupling between metasurface and molecular vibration | Coupling of metasurface resonance with a molecular vibration from weak - to - strong is demonstrated using different polymer based materials and metal-insulator-metal (MIM) metasurfaces. It is shown that the strength of coupling between MIM metasurface and molecular absorbance in the I-layer of organic nano-film depends on the dipole mode of the molecular vibration and the molecular number density. In the case of strong coupling, when Rabi splitting is observed at the molecular absorption band, the coupling efficiency reaches several percent of the particular molecular vibration modes in the volume below nano-disks of MIM metasurface. | Yoshiaki Nishijima; Saulius Juodkazis | Nanoscience; Plasmonic and Photonic Structures and Devices | CC BY 4.0 | CHEMRXIV | 2022-06-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6299a762195959994dbf51a4/original/platform-of-spectral-analysis-based-on-a-tunable-coupling-between-metasurface-and-molecular-vibration.pdf |
66d0f9a5f3f4b0529090377e | 10.26434/chemrxiv-2024-hjzcr-v2 | Modeling the ionization efficiency of small molecules in positive electrospray ionization | Technological advancements in liquid chromatography (LC) electrospray ionization (ESI) high resolution mass spectrometry (HRMS) have made it an increasingly popular analytical technique in non-targeted analysis (NTA) of environmental and biological samples. One critical limitation of current methods in NTA is the lack of available analytical standards for many of the compounds detected in biological and environmental samples. Computational approaches can provide estimates of concentrations by modeling the ionization efficiency of a compound expressed as the relative response factor (RRF). In this paper, we explore the application of molecular dynamics (MD) in the development of a predictive model for RRF. We obtained measurements of RRF for 48 compounds with LC - quadrupole time-of-flight (QTOF) MS and calculated their RRF by dividing the observed peak areas by their concentrations. We used the CGenFF force field to generate the topologies and GROMACS to conduct the (MD) simulations (t = 1 ns). We calculated the Lennard-Jones and Coulomb interactions between the analytes and all other molecules in the ESI droplet, which were then used to construct a multilinear regression model for predicting RRF. The best performing model showed a coefficient of determination (R2) of 0.82 and a mean absolute error (MAE) of 0.13 log units. This performance is comparable to other predictive models including machine learning models. While there is a need for further evaluation of diverse chemical structures, our approach showed great promise in predictions of RRF. | Dimitri Abrahamsson; Lelouda-Athanasia Koronaiou; Trevor Johnson; Dimitra Lambropoulou | Theoretical and Computational Chemistry; Analytical Chemistry; Earth, Space, and Environmental Chemistry; Analytical Chemistry - General; Mass Spectrometry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d0f9a5f3f4b0529090377e/original/modeling-the-ionization-efficiency-of-small-molecules-in-positive-electrospray-ionization.pdf |
629a07644f43d6708c2e566d | 10.26434/chemrxiv-2022-1cr26-v2 | Luminescence quenching in epitaxially grown PCN-224 type metal-organic frameworks | Core-shell and multivariant metal-organic frameworks (MOFs) of the PCN-224 type were prepared using metal-free and metalated porphyrin building blocks. Probing these MOFs with luminescence quenching upon exposure to oxygen reveals efficient gas transport and oxygen quenching in the core of the MOF. Undesirable energy transfer results in diminished contribution of the phosphorescence component in all mixed MOFs except for the physical mixture of individual crystals used as a reference. | Tobias Burger; Miriam Velásquez-Hernández; Robert Saf; Sergey M. Borisov; Christian Slugovc | Analytical Chemistry; Spectroscopy (Anal. Chem.); Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2022-06-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/629a07644f43d6708c2e566d/original/luminescence-quenching-in-epitaxially-grown-pcn-224-type-metal-organic-frameworks.pdf |
60f965d2537d10533a7ed161 | 10.26434/chemrxiv-2021-7xpm9 | Nacre-like alumina composites reinforced by zirconia particles | Nacre-like alumina is a class of bio-inspired ceramic composite manufactured by field-assisted sintering of green bodies made primarily of alumina platelets with an anisotropic microstructure. Here we investigate the addition of zirconia particles to enhance the mechanical properties of the composite. The resulting structure is a nacre- like anisotropic structure which features deflection and reinforcement during crack propagation. Monoclinic zirconia has no impact on the mechanical properties of the composite while tetragonal zirconia improves its fracture resistance properties. Both types of zirconia seem to slow down grain growth during sintering. The addition of zirconia stabilised in the tetragonal phase is thus a good option to obtain a composite with a fine microstructure and higher mechanical properties than a standard nacre-like alumina, with a flexural strength of 626 ± 39 MPa and a crack initiation toughness of 6.1 ± 0.6 MPa.m0.5. | Ronan Henry; Hassan Saad; Sandrine Dankic-Cottrino; Sylvain Deville; Sylvain Meille | Materials Science; Ceramics; Composites | CC BY 4.0 | CHEMRXIV | 2021-07-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60f965d2537d10533a7ed161/original/nacre-like-alumina-composites-reinforced-by-zirconia-particles.pdf |
66645c02e7ccf7753a4d068b | 10.26434/chemrxiv-2024-qvz7r | Size-dependent Magneto-catalytic Effect in Ferromagnetic Nanoparticles | The magneto-catalytic effect (MCE) indicates that the paramagnetic (PM) state of a ferromagnet could exhibit a distinct chemical reactivity from its ferromagnetic (FM) ground state. Recently, we have system-atically investigated the MCE on cobalt-catalyzed ammonia synthesis by ab initio spin dynamics. Howev-er, our model is still in the scope of ideal single-crystal facets rather than realistic nanoparticles (NPs). In this work, we employ an atomistic model using a nearest-neighbor Heisenberg Hamiltonian exchange to computationally study the size dependence of the MCE at nanoscale particles. As a result, the optimal reac-tion temperature for cobalt NPs to achieve the Sabatier optimal activity for ammonia synthesis can be de-creased by 300 K at an adequate particle size compared with that derived from bulk. We believe our find-ings could bridge the gap between the properties of bulk phase transition and the localized chemical reac-tions at heterogeneous interfaces. | Gaomou Xu; Tao Wang | Theoretical and Computational Chemistry; Catalysis; Heterogeneous Catalysis | CC BY 4.0 | CHEMRXIV | 2024-06-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66645c02e7ccf7753a4d068b/original/size-dependent-magneto-catalytic-effect-in-ferromagnetic-nanoparticles.pdf |
6731ccc3f9980725cfd10e57 | 10.26434/chemrxiv-2024-t16qt | Stable and responsive atropisomerism around a carbon–iodine bond | Atropisomerism, a critical form of molecular chirality originating from restricted bond rotation, enhances molecular diversity and plays a fundamental role in drug discovery, enantioselective catalysis, and materials science. While atropisomers with chiral axes composed of second-row elements, especially bulky biaryls, are common, stable atropisomerism around a “heavy” axis involving third-row or heavier elements remains rare. Here, we expand the scope of atropisomerism to the carbon–iodine bond, introducing the first stable atropisomers around this exceptionally long, flexible axis. Through a molecular design combining a conformationally restricted benziodoxole (BX) scaffold with a bulky fused aryl (Rind) groups, we achieve rotational barriers around the aryl–iodine bond exceeding 30 kcal mol–1 and racemization half-lives surpassing 50 years at room temperature, establishing the C–I bond as a viable stereogenic element. Notably, these C–I atropisomers exhibit acid-responsive racemization rates that vary with acidity, enabling semi-static or dynamic atropisomerism. This feature allows these compounds to serve as 19F-labeled NMR probes for weak chiral acids and as substrates for deracemization mediated by strong chiral acids. | Naohiko Yoshikai; Shohei Abe; Jun Kikuchi; Arimasa Matsumoto | Organic Chemistry; Organic Compounds and Functional Groups; Physical Organic Chemistry; Stereochemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-11-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6731ccc3f9980725cfd10e57/original/stable-and-responsive-atropisomerism-around-a-carbon-iodine-bond.pdf |
60c75481702a9bb2a718c533 | 10.26434/chemrxiv.13669214.v1 | A Graph-Convolutional Neural Network for Addressing Small-Scale Reaction Prediction | We describe a graph-convolutional neural network
(GCN) model whose reaction prediction capable as potent as the transformer
model on sufficient data, and adopt the Baeyer-Villiger oxidation to explore
their performance differences on limited data. The top-1 accuracy of GCN model
(90.4%) is higher than that of transformer model (58.4%). | Yejian Wu; Chengyun Zhang; Ling Wang; Hongliang Duan | Organic Synthesis and Reactions; Chemoinformatics; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-02-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75481702a9bb2a718c533/original/a-graph-convolutional-neural-network-for-addressing-small-scale-reaction-prediction.pdf |
60c74ff1bdbb89226fa39e4e | 10.26434/chemrxiv.12964598.v1 | Pd Supported Catalysts with Intrinsic Surface Electropositive Sites for Improved Selective Hydrogenation of Cinnamaldehyde | <p>Uniform-spherical
Pd nanoparticles (NPs) supported catalysts were prepared by a mild-temperature chemical
reduction method. Pd colloidal
suspension was wet-impregnated on various supports, P25-TiO<sub>2</sub>, SiO<sub>2</sub>,
and γ-Al<sub>2</sub>O<sub>3</sub>.<sub> </sub> In XPS, asymmetric Pd 3d<sub>5/2</sub> peak
reveals % surface concentration of Pd<sup>2+</sup> and Pd<sup>0 </sup>species.<sup>
</sup> The surface Pd<sup>2+</sup>/Pd<sup>0</sup>
ratio on the catalyst surface varied between ~1 to 0.15 depending on strong-metal
support interactions (SMSI) inferred from XPS and H<sub>2</sub>-TPR studies. A
linear correlation between Pd<sup>2+</sup>/Pd<sup>0</sup> ratio and turnover
frequency (TOF) was observed, with 1% Pd/P25-TiO<sub>2</sub> showing the
highest TOF/selectivity with Pd<sup>2+</sup>/Pd<sup>0</sup> ratio ~1.0, whereas
1% Pd/γ-Al<sub>2</sub>O<sub>3 </sub>showed the lowest TOF/selectivity with
lowest Pd<sup>2+</sup>/Pd<sup>0</sup> ratio 0.15. Interestingly, H<sub>2</sub>-TPR reveals PdH
decomposition peaks along with the Ti<sup>4+</sup> reduction peak, and XPS Ti
2p of 1% Pd/P25-TiO<sub>2</sub> indicates the presence of Ti<sup>3+</sup> in
TiO<sub>2</sub> lattice, which may have generated due to H<sub>2</sub>-spillover
from Pd to P25-TiO<sub>2</sub>. Hence, we
observed excellent COL selectivity (~90%) and 100 % conversion with 1.5% Pd/P25-TiO<sub>2
</sub>catalyst. Excellent COL selectivity
may be ascribed to small Pd NPs (~3 nm) with intrinsic surface electropositive
sites (Pd<sup>2+</sup>) created by partial reduction on the catalyst surface along
with SMSI. These electropositive sites
(Pd<sup>2+</sup>) promote preferential C=O adsorption. On the other hand, post-reduced catalyst in H<sub>2
</sub>@300 °C (1% Pd/P25-TiO<sub>2</sub>-PRH<sub>2</sub>) with large Pd NPs (~7
nm) showed significant selectivity loss (>50 %), which confirm significance
of small Pd NPs with electropositive sites. </p> | Surya Kumar Vatti; Kandasamy Konda R Krishnamurthy; Balasubramanian Viswanathan | Nanocatalysis - Catalysts & Materials; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74ff1bdbb89226fa39e4e/original/pd-supported-catalysts-with-intrinsic-surface-electropositive-sites-for-improved-selective-hydrogenation-of-cinnamaldehyde.pdf |
65ed9d2366c1381729ace1ef | 10.26434/chemrxiv-2024-vs01c | Percolation-induced ferrimagnetism from vacancy order in [Gua]Mn1–xFe2x/3(HCOO)3 hybrid perovskites | We report the magnetic behaviour of the hybrid perovskites [Gua]Mn1–xFe2x/3(HCOO)3 (0 < x < 0.88), showing that vacancy ordering drives bulk ferrimagnetism for x > 0.6. The behaviour is rationalised in terms of a simple microscopic model of percolation-induced ferrimagnetism. Monte Carlo simulations driven by this model reproduce the experimental dependence of magnetic susceptibility on x and show that, at intermediate compositions, domains of short-range vacancy order lead to the emergence of local magnetisation. Our results open up a new avenue for the design of multiferroic hybrid perovskites. | Johnathan Bulled; Alexandra Willis; Zoe Faure Beaulieu; Simon Cassidy; Jonas Bruckmoser; Hanna Boström; Andrew Goodwin | Physical Chemistry; Inorganic Chemistry; Magnetism; Solid State Chemistry; Materials Chemistry; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2024-03-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65ed9d2366c1381729ace1ef/original/percolation-induced-ferrimagnetism-from-vacancy-order-in-gua-mn1-x-fe2x-3-hcoo-3-hybrid-perovskites.pdf |
66422509418a5379b0268d18 | 10.26434/chemrxiv-2024-h72dt | Synthesis of pi-Extended [1.1]Paracyclophanes, [1.1][n]PCP (n = 2, 3, and 4), and Their Through-space Conjugation | [1.1][n]Paracyclophanes ([1.1][n]PCPs) (3) with n = 2, 3, and 4, which consist of two [n]paraphenylene units connected by methylene bridges, were synthesized using short synthetic pathways with good overall yields. Single-crystal X-ray diffraction analyses reveal that the paraphenylene unit in 3 is bent, resulting in an elliptic core structure of 3. The facing bridgehead carbons of the paraphenylene units are separated by a distance much shorter than the sum of the van der Waals radii of sp2-carbon atoms. UV-vis absorption spectra, fluorescence spectra, electrochemical measurements, and theoretical calculations were used to demonstrate the presence of through-space (TS) conjugation in 3. Furthermore, host-guest complex formation between 3D (n = 3) and tetracyanoquinodimethane in the solid state was revealed. | Shigeru Yamago; Eiichi Kayahara; Saya Hirata; Yoshiyuki Mizuhata; Yuka Yasuda; Yu Kusakabe; Hironori Kaji | Organic Chemistry; Organic Synthesis and Reactions; Physical Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-05-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66422509418a5379b0268d18/original/synthesis-of-pi-extended-1-1-paracyclophanes-1-1-n-pcp-n-2-3-and-4-and-their-through-space-conjugation.pdf |
60c748dc337d6c0d3ee27613 | 10.26434/chemrxiv.11991042.v1 | Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets Through a Transient CO-O Complex | We combine PLIF and NAP-XPS to investigate the CO oxidation reaction at vicinal Pt(111) surfaces in the millibar regime, using a curved sample. We find that the catalytic activation of Pt occurs in all vicinal planes simultaneously,<br />irrespectively of the reaction parameters. The systematic analysis of chemical species across the entire curved surface provides the clues for this surprising behavior. As the surface CO concentration decreases when approaching ignition, minor amounts of oxygen build up at both steps and (111) terraces. First-principles theory indicates that the latter is forming a CO-Pt-O complex that binds CO molecules to terraces strongly, leveling its adsorption energy to that of low-coordinated steps, and explaining why CO abruptly desorbs at the same temperature along the di erent crystal facets that make up the curved Pt surface. | Fernando Garcia-Martinez; Carlos Garc´ıa-Fern´andez; Juan Pablo Simonovi; Adrian Hunt; Andrew Walter; Iradwikanari Waluyo; Florian Bertram; Lindsay R. Merte; Mikhail Shipilin; Sebastian Pfaff; Sara Blomberg; Johan Zetterberg; Johan Gustafson; Edvin Lundgren; Daniel S´anchez-Portal; Frederik Schiller; Enrique ortega | Heterogeneous Catalysis; Nanocatalysis - Reactions & Mechanisms | CC BY NC ND 4.0 | CHEMRXIV | 2020-03-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c748dc337d6c0d3ee27613/original/catalytic-oxidation-of-co-on-a-curved-pt-111-surface-simultaneous-ignition-at-all-facets-through-a-transient-co-o-complex.pdf |
60c74edabb8c1af5a83db809 | 10.26434/chemrxiv.12813773.v1 | Effective Regulation of Polycaprolactone Molecular Weight and Oligomers Content Using Tetraphenyltin Catalyst | <p>There is a lack
of effective approaches that produce polycaprolactone materials (PCL) with a
high molecular weight, narrow polymer dispersity index (PDI), and fewer
formation of oligomers. The immigration of the remained oligomers predominantly
causes poor PCL quality and induces odor release. This limits the extensive
application of PCL materials. This study investigates the effects of different
catalysts and loadings on the PCL performance along with the formation of
oligomers in detail. The oligomers were successfully separated using gel
permeation chromatography (GPC). This was followed by a quantitative and
qualitative identification using high-resolution mass spectrometry (HRMS) and
low field nuclear magnetic (L-field NMR) analysis. The results show that tetraphenyltin
is an effective catalyst to promote the reaction and produce high-performance PCL that possesses the highest Mn
(65000), narrowest PDI (1.37), and the lowest content of oligomers (7.466 wt.%). Density functional theory (DFT) studies that were
combined with characterizing key intermediates verified that an anhydride bond
was formed close to the end hydroxyl group in the PCL chain because of the
special catalytic mechanism. This unusual chemical structure successfully
inhibited the chain from being broken by the “back-biting” behavior, which is
helpful for lowering the content of oligomers. This
study can provide a scalable synthetic approach to creating high-performance
polymers.</p><p><br /></p> | Caihong Gong; Jinxia Li; Chunwang Yi; Shuanglin Qu | Biopolymers; Organic Polymers; Polymerization (Polymers); Polymerization catalysts; Polymerization kinetics | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74edabb8c1af5a83db809/original/effective-regulation-of-polycaprolactone-molecular-weight-and-oligomers-content-using-tetraphenyltin-catalyst.pdf |
60f76162032114f18eb6aedf | 10.26434/chemrxiv-2021-5jq28 | Photoinduced Hydrocarboxylation via Thiol-Catalyzed Delivery of Formate Across Alkenes | Herein we disclose a new photochemical process to prepare carboxylic acids from formate salts and alkenes. This redox-neutral hydrocarboxylation proceeds in high yields across diverse functionalized alkene substrates with excellent regioselectivity. This operationally simple procedure can be readily scaled with low photocatalyst loading (0.01% photocatalyst) without the need for a flow reactor or any precautions to exclude air or moisture. Furthermore, this new reaction can leverage commercially available formate carbon isotologues to enable the direct synthesis of isotopically labeled carboxylic acids. Mechanistic studies support the working model involving a thiol-catalyzed radical chain process wherein the atoms from formate are delivered across the alkene substrate via CO2•– as a key reactive intermediate. | Sara Alektiar; Zachary Wickens | Organic Chemistry; Catalysis; Organic Synthesis and Reactions; Photochemistry (Org.); Organocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2021-07-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60f76162032114f18eb6aedf/original/photoinduced-hydrocarboxylation-via-thiol-catalyzed-delivery-of-formate-across-alkenes.pdf |
6733bea67be152b1d0df129c | 10.26434/chemrxiv-2024-v3w9x-v2 | On the mechanism of electron-beam-induced structural degradation in ZIF-8 and its electron dose tolerance | Zeolitic-imidazolate frameworks (ZIFs) are crystalline microporous materials with promising potential for gas adsorption and catalysis application. Further research advances include studies on integrating ZIFs into nanodevice concepts. In detail for the application, e.g., electron-beam-assisted structural modifications or patterning, there is a need to understand potential structural degradation processes caused by such electron beams.
Advanced transmission electron microscopy (TEM) has demonstrated its ability to study structures at the nanoscale. Here, we systematically investigated electron-beam-induced loss in crystallinity in ZIF-8 under various experimental conditions, using as measure the attenuation of the relative intensity and the relative displacement of electron diffraction Bragg planes with increasing cumulative electron dose. The {110} Bragg planes reflect the overall stability of the ZIF-8 unit-cell structure, while the {431} Bragg planes assess the stability of its micropore structure. We considered a relative loss of Bragg plane intensity of 37% as the threshold for determining the critical electron dose, which varied for different Bragg planes, with 35.6 ± 8.4 e-Å-2 for {110} and 11.4 ± 3.0 e-Å-2 for {431}. However, the critical dose per breakage of N-Zn bonds in a ZnN4 tetrahedra per different Bragg plane was found to be ~ 3 e-Å-2, which indicates continuous, simultaneous breakage of N-Zn bonds throughout the crystal, confirming radiolysis as the dominant damage mechanism.
In addition, we investigated the effects of TEM experiment parameters, including acceleration voltage, electron dose rate, cryogenic sample temperature, in-situ sample drying, and change in conductivity of the sample substrate (e.g., graphene). Our results unravel the degradation mechanisms in ZIF-8 and provide threshold parameters for maximizing resolution in electron-beam-assisted experiments and processes.
| Pritam Banerjee; Kathrin L. Kollmannsberger; Roland A. Fischer; Joerg Jinschek | Materials Science; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-11-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6733bea67be152b1d0df129c/original/on-the-mechanism-of-electron-beam-induced-structural-degradation-in-zif-8-and-its-electron-dose-tolerance.pdf |
60c74f68bb8c1a7af03db90f | 10.26434/chemrxiv.12895997.v1 | Encapsulation of Tricopper Cluster in a Protein-like Cavitand Enables Facile Redox Processes from CuICuICuI to CuIICuIICuII States | One-pot reaction of tris(2-aminoethyl)amine (TREN), [CuI
(MeCN)4]PF6, and paraformaldehyde affords a mixedvalent [TREN4CuIICuICuI
(3-OH)](PF6)3 complex. The macrocyclic azacryptand TREN4 contains four TREN motifs, three of
which provide a bowl-shape binding pocket for the [Cu3(3-OH)]3+ core. The fourth TREN caps on top of the tricopper cluster to
form a cavitand, imposing conformational constraints and preventing solvent interaction. Contrasting the limited redox capability of
synthetic tricopper complexes reported so far, [TREN4CuIICuICuI
(3-OH)](PF6)3 exhibits several reversible single-electron redox
events. The distinct electrochemical behaviors of [TREN4CuIICuICuI
(3-OH)](PF6)3 and its solvent-exposed analog
[TREN3CuIICuIICuII
(3-O)](PF6)4 suggest that isolation of tricopper core in a protein-like cavitand enables facile electron transfer,
allowing potential application of synthetic tricopper complexes as redox catalysts. Indeed, the fully reduced [TREN4CuICuICuI
(3-
OH)](PF6)2 can reduce O2 under acidic conditions. The geometric constraints provided by the cavitand are reminiscent of Nature’s
multicopper oxidases (MCOs). For the first time, a synthetic tricopper cluster was isolated and fully characterized at CuICuICuI
(4a), CuIICuICuI
(4b), and CuIICuIICuI
(4c) state, providing structural and spectroscopic models for many intermediates in MCOs.
Fast electron transfer rates (105
- 106 M −1
s
−1
) were observed for both CuICuICuI
/CuIICuICuI
and CuIICuICuI
/CuIICuIICuI
redox couples, approaching the rapid electron transfer rates of copper sites in MCO. | Shiyu Zhang; Weiyao Zhang; Curtis Moore | Bioinorganic Chemistry; Coordination Chemistry (Inorg.); Electrochemistry; Small Molecule Activation (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74f68bb8c1a7af03db90f/original/encapsulation-of-tricopper-cluster-in-a-protein-like-cavitand-enables-facile-redox-processes-from-cu-i-cu-i-cu-i-to-cu-ii-cu-ii-cu-ii-states.pdf |
620a360d7d068afb7e1f14aa | 10.26434/chemrxiv-2022-qfj83 | Highly sensitive electrochemical sensor for the detection of Shiga toxin-producing E. coli using interdigitated micro-electrodes selectively modified with a chitosan-gold nanocomposite | Shiga toxin-producing E. coli (STEC) is a food-borne pathogen of significant concern due to the severity of the disease it can cause. Herein we report the development of a highly sensitive, label-free, electrochemical DNA-based sensor for detection of stx1 gene using interdigitated gold microelectrodes (IDEs) on fully integrated silicon chips. Each IDE comprised a working IDE, used for DNA probe immobilisation and generator IDE used for accumulation of methylene blue. First, the working IDE was modified with gold nanoparticles (Au NPs) and chitosan gold nanocomposite. Afterwards, amine-modified probe DNA was immobilised on the chitosan modified electrode using glutaraldehyde as a linker. The label-free electrochemical detection was undertaken using methylene blue as a redox molecule, which intercalated into the double-strand DNA after applying an open potential circuit at the generator IDEs. Reduction of methylene blue was recorded using square wave voltammetry (SWV). Using this label-free detection, we have achieved linear response between 10-16 and 10-6 M synthetic target strand with the lowest limit of detection of 100 aM after 20 minutes hybridisation time. The chromosomal DNA from four different E. coli strains (two stx1 positives and two stx1 negatives) was used to confirm the selectivity of the presented method. This novel on-chip biosensor for the detection of STEC has the potential to be used in point-of-use detection, for example, on the farm. | Luiza Wasiewska; Fernando Diaz; Han Shao; Catherine Burgess; Geraldine Duffy; Alan O'Riordan | Analytical Chemistry; Agriculture and Food Chemistry; Electrochemical Analysis | CC BY 4.0 | CHEMRXIV | 2022-03-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/620a360d7d068afb7e1f14aa/original/highly-sensitive-electrochemical-sensor-for-the-detection-of-shiga-toxin-producing-e-coli-using-interdigitated-micro-electrodes-selectively-modified-with-a-chitosan-gold-nanocomposite.pdf |
6372bfc874b7b6da1efd9527 | 10.26434/chemrxiv-2022-x9ztv | Ringtail: a Python tool for efficient management and storage of virtual screening results | Virtual screening using molecular docking is now routinely used for the rapid evaluation of very large ligand libraries. As such, it has become an increasingly common approach in early-stage drug discovery. These screenings generate large amounts of data proportional to the size of the compound library used, which must be stored and filtered before visual analysis. As the size of compound libraries which can feasibly be screened grows, so do the challenges in result management and storage. Here we introduce Ringtail, a new Python tool in the AutoDock Suite for efficient storage and analysis of virtual screening data based on portable SQLite databases. Although Ring- tail is designed to work with AutoDock-GPU and AutoDock Vina out-of-the-box, its modular design allows for easy extension to support input file types from other dock- ing software, different storage solutions, and its incorporation into other applications. Ringtail’s SQLite database output can dramatically reduce the required storage by selecting individual poses to store and by taking advantage of the relational database format. We observed disk usage reductions of between 36-46 fold compared to raw AutoDock-GPU DLG output for a 50-pose docking and, and more than 3 times more efficient than achievable by only the reduction of stored poses. Filtering times are also dramatically reduced, requiring minutes to filter millions of ligands. Thus, Ring- tail a tool that can immediately integrate into existing virtual screening pipelines using AutoDock-GPU and Vina, and both scriptable and modifiable to fit specific user needs. | Althea Hansel-Harris; Andreas Tillack; Diogo Santos-Martins; Matthew Holcomb; Stefano Forli | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Bioinformatics and Computational Biology; Computational Chemistry and Modeling; Chemoinformatics - Computational Chemistry | CC BY 4.0 | CHEMRXIV | 2022-11-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6372bfc874b7b6da1efd9527/original/ringtail-a-python-tool-for-efficient-management-and-storage-of-virtual-screening-results.pdf |
640ecd3c7290f69f8ee7179f | 10.26434/chemrxiv-2023-b6jxk | One-step antibacterial modification of polypropylene nonwoven fabrics via oxidation using photo-activated chlorine dioxide radicals | In the fields of sanitation and medicine, there is an urgent need for the development of convenient methods for imparting antibacterial properties to materials. Polypropylene nonwoven fabrics (PP NWFs) are one of the most common polymer materials; however, it is difficult to impart antibacterial properties to PP NWFs due to their low reactivity and complicated structures. In this study, we discovered that oxidation using photo-activated chlorine dioxide radical (ClO2) gas is a useful method for antibacterial modification of PP NWFs, without the need for any antibacterial agents or multi-step treatments. The as-prepared PP NWFs exhibited excellent antibacterial activity against both Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Interestingly, the solvent used to wash the product was analyzed to reveal the formation of nanoparticles around 80 nm in diameter during the oxidation step, particularly at 80 C. | Keita Yamamoto; Haruyasu Asahara; Kazuo Harada; Yuki Itabashi; Kei Ohkubo; Tsuyoshi Inoue | Biological and Medicinal Chemistry; Polymer Science | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/640ecd3c7290f69f8ee7179f/original/one-step-antibacterial-modification-of-polypropylene-nonwoven-fabrics-via-oxidation-using-photo-activated-chlorine-dioxide-radicals.pdf |
679932156dde43c908bf9bb4 | 10.26434/chemrxiv-2024-ff7s8-v2 | Microenvironment effects from first principles multiscale modeling of electrochemical CO2 reduction | Electrochemical CO2 reduction will be a key player in net-zero technologies, yet its industrial implementation is limited. Improvements by fine-tuning the microenvironments, electrolyte environments around the catalytic sites, have been scarce due to the interplay between electrode kinetics and transport. Here, we couple atomistic insights with continuum transport via ab-initio multiscale modeling, explicitly including electrolyte effects at all scales. The model was validated on Ag planar electrodes in several liquid electrolytes and the current dependence with voltage aligns with experimental observations. We show that a balance between CO2 diffusion and cation accumulation needs be achieved to obtain optimal rates. In ionomers, this limitation can be overcome since organic cations-based microenvironments are present at a fixed concentration, but water management becomes critical. Our approach paves the way towards rational microenvironment design in electrochemical CO2 conversion. | Francesca Lorenzutti; Ranga Seemakurthi; Evan Johnson; Santiago Morandi; Pavle Nikacevic; Nuria Lopez; Sophia Haussener | Theoretical and Computational Chemistry; Energy; Chemical Engineering and Industrial Chemistry | CC BY 4.0 | CHEMRXIV | 2025-01-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/679932156dde43c908bf9bb4/original/microenvironment-effects-from-first-principles-multiscale-modeling-of-electrochemical-co2-reduction.pdf |
60c74436469df4e7a2f432d3 | 10.26434/chemrxiv.9758600.v1 | Comparison Between SMILES-Based Differential Neural Computer and Recurrent Neural Network Architectures for De Novo Molecule Design | In recent years, deep learning for de novo molecular generation has become a rapidly growing research area. Recurrent neural networks (RNN) using the SMILES molecular representation is one of the most common approaches used. Recent study shows that the differentiable neural computer (DNC) can make considerable improvement over the RNN for modeling of sequential data. In the current study, DNC has been implemented as an extension to REINVENT, an RNN-based model that has already been used successfully to make de novo molecular design. The model was benchmarked on its capacity to learn the SMILES language on the GDB-13 and MOSES datasets. The DNC shows improvement on all test cases conducted at the cost of significantly increased computational time and memory consumption. | Simon Viet Johansson; Oleksii Prykhodko; Josep Arús-Pous; Ola Engkvist; Hongming Chen | Computational Chemistry and Modeling; Machine Learning; Artificial Intelligence; Chemoinformatics - Computational Chemistry | CC BY NC 4.0 | CHEMRXIV | 2019-09-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74436469df4e7a2f432d3/original/comparison-between-smiles-based-differential-neural-computer-and-recurrent-neural-network-architectures-for-de-novo-molecule-design.pdf |
65cbed619138d231610f1a7b | 10.26434/chemrxiv-2023-9b5k7-v3 | Making sense of chaos: uncovering the mechanisms of conformational entropy | During protein folding, proteins transition from a disordered polymer into a globular structure, markedly decreasing their conformational degrees of freedom and consequently leading to a substantial reduction in entropy. Nonetheless, folded proteins still retain significant entropy as they fluctuate between the conformations that make up their native state. This residual entropy contributes to crucial functions like binding or catalysis. Here, we outline three major ways that protein use conformational entropy to perform their functions; first, pre-paying entropic cost through ordering of the ground state; second, spatially redistributing entropy, where an decrease in entropy in one area is reciprocated by an increase in entropy elsewhere; third, populating catalytically-competent ensembles, where conformational entropy within the enzymatic scaffold aids in lowering transition state barriers. Given the growing evidence of the biological significance of conformational entropy, emerging largely from NMR and simulation studies, solving the current challenge of structurally defining the ensembles encoding conformational entropy will open new paths for control of binding, catalysis, and allostery. | Stephanie Wankowicz; James Fraser | Biological and Medicinal Chemistry; Biochemistry; Biophysics; Chemical Biology | CC BY 4.0 | CHEMRXIV | 2024-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65cbed619138d231610f1a7b/original/making-sense-of-chaos-uncovering-the-mechanisms-of-conformational-entropy.pdf |
67812b9381d2151a029837d3 | 10.26434/chemrxiv-2024-5f7x4-v2 | Ruthenocenoporphyrinoids - π-Conjugation Transmitted Across 1,3-Substituted Ruthenocene | Synthesis of ruthenocenoporphyrinoids, wherein the [RuCp*]+ moiety coordinates to the cyclopentadienyl π-surface of the 21-carba-23-selenaporphyrin macrocyclic platform has been developed. The NICS 2D maps and EDDB plots gave an insight into the aromaticity and effectiveness of π-conjugation across 1,3-substituted ruthenocene in obtained hybrid molecules. | Anna Berlicka; Aleksandra Walczak; Michał Białek; Katarzyna Ślepokura; Piotr Chmielewski; Lechosław Latos-Grażyński | Physical Chemistry; Organometallic Chemistry; Coordination Chemistry (Organomet.); Ligand Design; Structure | CC BY 4.0 | CHEMRXIV | 2025-01-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67812b9381d2151a029837d3/original/ruthenocenoporphyrinoids-conjugation-transmitted-across-1-3-substituted-ruthenocene.pdf |
660ad03a9138d23161e35596 | 10.26434/chemrxiv-2024-4719t | Mothra: Multi-objective de novo Molecular Generation using Monte Carlo Tree Search | In the field of drug discovery, identifying compounds that satisfy multiple criteria, such as target protein affinity, pharmacokinetics, and membrane permeability, is challenging because of the vast chemical space. Until now, multi-objective optimization using generative models has often involved linear combinations of different reward functions, turning multi-objective optimization into a single-objective task and causing problems with weighting for each individual objective. Herein we propose a scalable multi-objective molecular generative model developed using deep learning techniques. This model integrates the capabilities of recurrent neural networks for molecular generation and Pareto multi-objective Monte Carlo tree search to determine the optimal search direction. Through this integration, our model can generate compounds using enhanced evaluation functions that include important aspects like target protein affinity, drug similarity, and toxicity. The proposed model addresses the limitations of previous linear combination methods, and its effectiveness is demonstrated via extensive experimentation. The improvements achieved in the evaluation metrics underscore the potential utility of our approach toward drug discovery applications. In addition, we provide the source code for our model such that researchers can easily access and use our framework in their own investigations. The source code is available at https://github.com/sekijima-lab/Mothra. | Takamasa Suzuki; Dian Ma; Nobuaki Yasuo; Masakazu Sekijima | Theoretical and Computational Chemistry; Organic Chemistry; Organic Compounds and Functional Groups; Machine Learning; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/660ad03a9138d23161e35596/original/mothra-multi-objective-de-novo-molecular-generation-using-monte-carlo-tree-search.pdf |
639daf0104902aea3f065dc3 | 10.26434/chemrxiv-2022-g304d | Phase Behaviour of Alkyl Ethoxylate Surfactants in a Dissipative Particle Dynamics Model | We present a dissipative particle dynamics (DPD) model capable of capturing the liquid state phase behaviour of non-ionic surfactants from the alkyl ethoxylate (CnEm) family. The model is based upon our recent work [Anderson et al., J. Chem. Phys. 2017, 147, 094503] but adopts tighter control of the molecular structure by setting the bond angles with guidance from molecular dynamics simulations. Changes to the geometry of the surfactants were shown to have little effect on the predicted micelle properties of sampled surfactants, or the water-octanol partition coefficients of small molecules, when compared to the original work. With these modifications the model is capable of reproducing the binary water-surfactant phase behaviour of nine surfactants (C8E4, C8E5, C8E6, C10E4, C10E6, C10E8, C12E6, C12E8 and C12E12) with a good degree of accuracy. | Richard Anderson; David Gunn; Tseden Taddese; Ennio Lavagnini; Patrick Warren; David Bray | Theoretical and Computational Chemistry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2022-12-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/639daf0104902aea3f065dc3/original/phase-behaviour-of-alkyl-ethoxylate-surfactants-in-a-dissipative-particle-dynamics-model.pdf |
63dde2071f23f0032d3b550e | 10.26434/chemrxiv-2023-93qzq | Unveiling the Critical Role of Ion Coordination Configuration of Ether Electrolytes for High Voltage Lithium Metal Batteries | Ethers with distinctive reduction stability are emerging as the promising solution to the issues of lithium (Li) metal anode. However, their inferior oxidation stability (<4.0 V vs. Li/Li+) cannot meet the ever-growing needs of high-voltage cathodes. Studies of ether electrolytes have been focusing on the archetype glyme structure with ethylene oxide moieties. Herein, we systematically vary the methylene units in the ether backbone and unveil the crucial effect of ion-ether coordination configuration on the electrolyte oxidation stability. The 1,3-dimethoxypropane (DMP, C3) molecule forms a unique six-membered chelating complex with Li+, whose stronger solvating ability suppresses undesired oxidation side reactions. In addition, the favored hydrogen transfer reaction between DMP and salt anion induces a dramatic enrichment of LiF (a total atomic ratio of 76.7%) on the cathode surface. As a result, the DMP-based electrolyte demonstrates stable cycling of nickel-rich cathodes under a high voltage of 4.7 V (87% capacity retention after 150 cycles). This study offers fundamental insights into rational electrolyte design with wide electrochemical stability window for developing high-energy-density batteries. | Shunqiang Chen; Jiajia Fan; Zhuangzhuang Cui; Lijiang Tan; Digen Ruan; Xin Zhao; Jinyu Jiang; Shuhong Jiao; Xiaodi Ren | Energy; Energy Storage; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-02-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63dde2071f23f0032d3b550e/original/unveiling-the-critical-role-of-ion-coordination-configuration-of-ether-electrolytes-for-high-voltage-lithium-metal-batteries.pdf |
61f178cf4b95002eba0ad43a | 10.26434/chemrxiv-2022-vf5gm | Direct Light Activation of Hypervalent Iodine Reagents: Substrate-Controlled C-C or C-H Alkynylation of Cyclopropanes | We report the direct light activation of ethynylbenziodoxolone (EBX) reagents for the oxyalkynylation of aryl- and amino-cyclopropanes as well as styrenes. Irradiation with visible light at 440 nm promoted the reaction without the need of a photocatalyst. By the choice of the aryl group on the cyclopropane, it was possilbe to completely switch the outcome of the reaction from the oxyalkynylation of the C-C bond to the alkynylation of the C-H bond. This effect has been speculatively attributed to the conformational control induced by the aryl group on the cyclopropane ring | Tin. V. T. Nguyen; Jerome Waser | Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Photochemistry (Org.) | CC BY 4.0 | CHEMRXIV | 2022-01-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61f178cf4b95002eba0ad43a/original/direct-light-activation-of-hypervalent-iodine-reagents-substrate-controlled-c-c-or-c-h-alkynylation-of-cyclopropanes.pdf |
6442866edf78ec501525d6d2 | 10.26434/chemrxiv-2023-z1hq1 | Role of Cyclopentyl methyl ether co-solvent in Improving SEI layer stability in Hard Carbon Anode for Sodium-ion Batteries | The conversion of polyethylene terephthalate (PET) municipal waste via the carbonization process into hard carbon (WPET-HC) delivers a high-performing, low-cost, sustainable anode material for sodium-ion batteries (SIBs). To further optimize the anode, electrolytes and interfacial chemistry are critical in improving cycling stability and rate capability. Herein, cyclopentyl methyl ether (CPME), a weakly solvating and a wide temperature solvent, is used as an alternative co-solvent to ethylene carbonate (EC) to deliver a high initial coulombic efficiency (ICE) up to 75%. The larger interlayer spacing, low surface area, and slit-shaped micro and mesoporous presence in the WPET-HC structure enhance the low potential plateau capacity to 68%, showing a more battery-type anode material from plastic trash. The WPET-HC delivered the excellent reversible capacity of 356 mAh g-1 at the current density of 30 mA g-1 with superior cycling of 91% after 100 cycles using CPME-PC-based electrolyte. The reduction of CPME co-solvent forms a more inorganic SEI than EC-generated SEI, providing a stable and thin SEI layer boosting the ICE and cycling stability of the anode. The low-temperature battery metric for CPME-PC-based electrolytes showed ~30% added capacity and improved ICE value compared to EC-PC-based electrolytes. The CPME-PC-based electrolyte maintained the higher capacity retention of 88% and 74% at 10℃ and 0℃, respectively, with a coulombic efficiency of 100%, revealing the excellent stability of the electrolyte with the HC anode. The work provides an eco-friendly approach to developing hard carbons from plastic trash and reports for the first time the use of greener, low-solvating CPME in improving the reversible capacity and ICE for low-temperature applications of SIBs. | Nagmani .; Dhrubajyoti Das; Sreeraj Puravankara | Materials Science; Energy; Carbon-based Materials; Energy Storage; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6442866edf78ec501525d6d2/original/role-of-cyclopentyl-methyl-ether-co-solvent-in-improving-sei-layer-stability-in-hard-carbon-anode-for-sodium-ion-batteries.pdf |
64353407a41dec1a56df1ba4 | 10.26434/chemrxiv-2023-vtfq8-v2 | Influence of precursor structure on the formation of tungsten oxide polymorphs | Understanding material nucleation processes is crucial for the development of synthesis pathways for tailormade materials. However, we currently have little knowledge of the influence of the precursor solution structure on the formation pathway of materials. We here use in situ total scattering to show how the precursor solution structure influences which crystal structure is formed during the hydrothermal synthesis of tungsten oxides. We investigate the synthesis of tungsten oxide from the two polyoxometalate salts, ammonium metatungstate and ammonium paratungstate. In both cases, a hexagonal ammonium tungsten bronze (NH4)0.25WO3, is formed as the final product. If the precursor solution contains metatungstate clusters, this phase forms directly in the hydrothermal synthesis. However, if the paratungstate B cluster is present at the time of crystallization, a metastable intermediate phase in the form of a pyrochlore-type tungsten oxide, WO30*5H2O, initially forms. The pyrochlore structure then undergoes a phase transformation into the tungsten bronze phase. Our studies thus experimentally show that the precursor cluster structure present at the moment of crystallization directly influences the formed crystalline phase and suggest that the precursor structure just prior to crystallization can be used as a tool for targeting specific crystalline phases of interest. | Mikkel Juelsholt; Olivia Aalling-Frederiksen; Troels Lindahl Christiansen; Emil T. S. Kjær; Niels Lefeld; Andrea Kirsch; Kirsten M. Ø. Jensen | Nanoscience; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64353407a41dec1a56df1ba4/original/influence-of-precursor-structure-on-the-formation-of-tungsten-oxide-polymorphs.pdf |
60c750f70f50db270b39768f | 10.26434/chemrxiv.13071821.v2 | Trioxatriangulenium (TOTA+) as a Robust Carbon-based Lewis Acid in Frustrated Lewis Pair Chemistry | We report the reactivity between the Lewis acidic trioxatriangulenium ion (TOTA<sup>+</sup>) and a series of Lewis bases such as phosphines and <i>N</i>-heterocyclic carbene (NHC). The nature of the Lewis acid-base interaction was analyzed via variable temperature (VT) NMR spectroscopy, single-crystal X-ray diffraction, UV-visible spectroscopy, and DFT calculations. While small and strongly nucleophilic phosphines, such as PMe<sub>3</sub>, led to the formation of a stable Lewis acid-base adduct, frustrated Lewis pairs (FLPs) were observed for sterically hindered bases such as P(<i><sup>t</sup></i>Bu)<sub>3</sub>. The TOTA<sup>+</sup>-P(<i><sup>t</sup></i>Bu)<sub>3</sub> FLP was characterized as an encounter complex, and was found to promote the heterolytic cleavage of disulfide bonds, formaldehyde fixation, dehydrogenation of 1,4-cyclohexadiene, heterolytic cleavage of C–Br bond, and interception of Staudinger reaction intermediate. Moreover, TOTA<sup>+</sup> and NHC was found to first undergo single-electron transfer (SET) to form [TOTA]<sup>•</sup>[NHC]<sup> •+</sup>, which was confirmed via electron paramagnetic resonance (EPR) spectroscopy, and subsequently form a [TOTA-NHC]<sup>+</sup> adduct or a mixture of products depending the reaction condition used. | Aslam Shaikh; Jose M Veleta; Jules Moutet; thomas Gianetti | Frustrated Lewis Pairs | CC BY NC ND 4.0 | CHEMRXIV | 2020-10-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c750f70f50db270b39768f/original/trioxatriangulenium-tota-as-a-robust-carbon-based-lewis-acid-in-frustrated-lewis-pair-chemistry.pdf |
61f91f32e4d9b86ba4ff2df0 | 10.26434/chemrxiv-2022-fd950 | Property-selected Asymmetric Azobenzenes for Photoswitchable Ligands | Suitable designed photoswitches based on azobenzenes are essential structural features for photopharmacological compounds. Optimized azobenzenes are important for serving as building blocks in „azo extension“ strategies, and for designing photodrugs with tailored properties. Herein we present the synthesis and characterization of a variety of asymmetric azobenzenes by addressing selected structural features of the diazene core, such as polarity, steric demand, and electronical properties. Systematic exploration led to photoswitches with a relaxation half-life of seconds, minutes, hours, or days. Furthermore, the influence of different substitution pattern on the photophysical properties was charted. For analysis of all switches, robust characterization as well as examination under near-to physiological conditions was established, in order to assist with photoswitch choice for specific biological applications. | Florian Kuellmer; Lucas Gregor; Hans-Dieter Arndt | Organic Chemistry; Bioorganic Chemistry; Organic Synthesis and Reactions; Photochemistry (Org.) | CC BY NC ND 4.0 | CHEMRXIV | 2022-02-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61f91f32e4d9b86ba4ff2df0/original/property-selected-asymmetric-azobenzenes-for-photoswitchable-ligands.pdf |
64b6bf41b053dad33a786b51 | 10.26434/chemrxiv-2023-hqtqv | NaBH4 Hydrolysis for Hydrogen Generation over Metal-Organic Frameworks (Cu-BTC) | Hydrogen gas (H2) is widely acknowledged as a sustainable and environmentally friendly energy carrier. In this study, we examined the potential of copper-based metal-organic frameworks (MOFs); copper-benzene-1,3,5-tricarboxylate (Cu-BTC), as catalysts for the release of hydrogen through the hydrolysis of sodium borohydride (NaBH4). Cu(BTC) exhibited a hydrogen generation rate (HGR) of 4386 mLH2 gcat-1 min-1 using low catalyst loading of 1 mg. The effect of the reactant weight percentage of NaBH4 )0.2-3 wt.%) at room temperature was investigated. Thermal analysis of the hydrolysis process revealed that Cu-BTC MOF exhibits low activation energy of 41.7 kJ mol-1. The study investigated the recyclability of the catalyst and found that it could sustain catalytic hydrogen generation for up to four cycles without any noticeable decline in performance. This research demonstrated that Cu(BTC) is an inexpensive, efficient, and reusable catalyst for generating hydrogen through hydride hydrolysis. | Hani Nasser Abdelhamid; Zeinab Hussein Hashem; Laila H. Abdel-Rahman; Santiago Gomez | Inorganic Chemistry; Nanoscience; Energy | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64b6bf41b053dad33a786b51/original/na-bh4-hydrolysis-for-hydrogen-generation-over-metal-organic-frameworks-cu-btc.pdf |
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