jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Katerina M. Korch | Jacob C. Hayes | Raphael S. Kim | Jessica Sampson | Austin T. Kelly | Donald A. Watson
Source: ChemRxiv (preprint, 2022-04-05)
Field: Chemistry — Spectroscopy

Selected Ion Monitoring Using Low-Cost Mass Spectrum Detectors Provide a Rapid, General, and Accurate Method for Enantiomeric Excess Determination in High Throughput Experimentation High-Throughput Experimentation (HTE) workflows are efficient means of surveying a broad array of chiral catalysts in the development of catalytic asymmetric reactions. However, use of traditional HPLC-UV/vis methodology to determine enantiomeric excess (ee) from the resulting reactions is often hampered by coelution of other reaction components, resulting in erroneous ee determination when crude samples are used, and ultimately requiring product isolation prior to ee analysis. In this study, using four published reactions selected as model systems, we demonstrate that the use of LC-MS, SFC-MS, and selected ion monitoring (SIM) mass chromatography provides a highly accurate means to determine ee of products in crude reaction samples using commonplace, low-cost MS detectors. By using ion selection, co-eluting signals can be deconvoluted to provide accurate integrations of the target analytes. We also show that this method is effective for samples lacking UV/vis chromophores, making it ideal for HTE workflows in asymmetric catalysis. Analyte ; Detector ; Chemistry ; Throughput ; Catalysis ; Enantiomeric excess ; Chromatography ; Mass spectrometry ; Workflow ; Analytical Chemistry (journal) ; Computer science ; Combinatorial chemistry ; Organic chemistry ; Enantioselective synthesis Analytical Chemistry and Chromatography ; Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Nur Rahimah Said | Majid Rezayi | Ninie Suhana Abdul Manan | Amirhossein Sahebkar | Yatimah Alias
Source: Analytical Methods in Environmental Chemistry Journal (article, 2022-06-01)
Field: Materials Science — Polymers and Plastics

Analysis of complexation between new bidentate bis-NHC ligand and some metal cations at different temperature In this research, the determination and complexation process between 3,3'-(2,2'-(4-methyl-phenylenesulfonamido)bis(ethane-2,1-diyl))bis(1-benzyl-3H-benzo[d]imidazol-1-ium)dibromide with Ni2+, Zn2+, Pd2+, Ag+, and Hg2+ cations in the binary mixture of methanol (MeOH) and water (H2O) at different temperatures (15, 25, 35 and 45ºC) were studied using a conductometric method. The results show that the stoichiometry of the complexes in all binary mixed solvents for Ni2+, Zn2+, and Pd2+ were 1:1 (M:L), while in other cases 1:2 (M:L) and 2:1(M:L). The stability constants (log ) of complex formation have been determined by fitting molar conductivity curves using a computer program (GENPLOT). The obtained data shows that in the pure methanol solvent system, the stability order is Ni2+&lt; Pd2+&lt;Zn2+&lt;Hg2+&lt;Ag+ and the complexation process seems more stable in pure methanol in most cases. The thermodynamic parameters were determined conductometrically. The complexes in all cases were found to be enthalpy destabilized but entropy stabilized. The experimental data was tested by using an artificial neural network (ANN) program and was in good agreement with the estimated data. Chemistry ; Methanol ; Enthalpy ; Denticity ; Stoichiometry ; Metal ; Standard molar entropy ; Solvent ; Inorganic chemistry ; Molar conductivity ; Ligand (biochemistry) ; Physical chemistry ; Standard enthalpy of formation ; Thermodynamics ; Organic chemistry Conducting polymers and applications ; Multicomponent Synthesis of Heterocycles ; Ionic liquids properties and applications
Authors: Justus Wöhl | Wassja A. Kopp | Iryna Yevlakhovych | Leo Bahr | Hans‐Jürgen Koß | Kai Leonhard
Source: ChemRxiv (preprint, 2022-01-03)
Field: Chemistry — Analytical Chemistry

Completely computational model setup for spectroscopic techniques: the ab initio molecular dynamics indirect hard modeling (AIMD-IHM) approach The spectroscopic quantification of mixture compositions usually requires pure compounds and mixtures of known composition for calibration. Since they are not always available, methods to fill such gaps have evolved, which are, however, not generally applicable. Therefore, calibration can be extremely challenging, especially when multiple instable species, e.g. intermediates, exist in a system. This study presents a new calibration approach that uses ab initio Molecular Dynamics (AIMD)-simulated spectra as to set up and calibrate models for the physics-based spectral analysis method Indirect Hard Modeling (IHM). To demonstrate our approach called AIMD-IHM, we analyze Raman spectra of ternary hydrogen-bonding mixtures of acetone, methanol, and ethanol. The derived AIMD-IHM pure-component models and calibration coefficients are in good agreement with conventionally generated experimental results. The method yields compositions with prediction errors of less than 5% without any experimental calibration input. Our approach can be extended, in principle, to IR and NMR spectroscopy and allows for the analysis of systems that were hitherto inaccessible to quantitative spectroscopic analysis. Calibration ; Raman spectroscopy ; Ternary operation ; Molecular dynamics ; Component (thermodynamics) ; Ab initio ; Chemistry ; Computational chemistry ; Statistical physics ; Biological system ; Materials science ; Computer science ; Thermodynamics ; Physics ; Quantum mechanics ; Organic chemistry Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Advanced Chemical Sensor Technologies
Authors: Michael K. Bogdos | Patrick Müller | Bill Morandi
Source: ChemRxiv (preprint, 2022-11-07)
Field: Chemistry — Organic Chemistry

Structural Evidence for Aromatic Heterocycle N–O Bond Activation via Oxidative Addition Many methods report the scission of the N–O bonds of aromatic heterocycles and their subsequent functionalization. Oxidative addition is one of the presumed pathways through which aromatic N–O bond activation with transition metals is achieved. We report the first well-defined pathway of (benz)isoxazole’s aromatic N–O bond activation through oxidative addition. We also provide control experiments which show that aromatic N–O bonds may be broken by strong inorganic reductants. These results highlight that N–O bonds are susceptible to both reduction and oxidative addition, which has important implications for catalysis. Exploring the reactivity of one of these complexes towards a series or electrophiles led to the discovery of a Staudingertype β-lactam synthesis upon reaction with a ketene. Finally, we demonstrate that choice of different metal/ligand combinations allows for selective oxidative addition into either C–I bonds or N–O bonds in the presence of the other. Chemistry ; Electrophile ; Reactivity (psychology) ; Oxidative addition ; Bond cleavage ; Oxidative phosphorylation ; Electrophilic addition ; Ligand (biochemistry) ; Ketene ; Electrophilic aromatic substitution ; Aromaticity ; Reductive elimination ; Stereochemistry ; Medicinal chemistry ; Catalysis ; Combinatorial chemistry ; Organic chemistry ; Molecule ; Receptor Synthesis of β-Lactam Compounds ; Oxidative Organic Chemistry Reactions ; Synthesis and Catalytic Reactions
Authors: Satya Prakash Singh
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2022-10-20)
Field: Chemistry — Spectroscopy

PHYSICOCHEMICAL PROPERTIES OF SILICA NANOPARTICLES AND HEALTH HAZARDS Large-scale industrial production and global commercialization of Silica Nanoparticles in recent year had resulted in increased risk of human exposures. However, there is a lack of knowledge on the health and environmental effects of such substances and information on their handling and disposal is also frequently incomplete. The current article, review, the physicochemical properties of the different nanosized silica materials that can affect their interaction with biological systems. The article also discuss the biological mechanisms involve in generating toxicity of nanosilica (both crystalline and amorphous), genotoxicity, immunotoxicity, ecotoxicity, workplace exposure, handling practices and alternatives of disposal of silica aerogels nanoparticle. Nanoparticle ; Nanotechnology ; Chemical engineering ; Materials science ; Engineering Adsorption, diffusion, and thermodynamic properties of materials ; Analytical chemistry methods development ; Adsorption and biosorption for pollutant removal
Authors: Tamara Ehm | Hila Shinar | Guy Jacoby | Sagi Meir | Gil Koren | M. Segal | Joanna Korpanty | Matthew P. Thompson | Nathan C. Gianneschi | Michael M. Kozlov | Salome Azoulay‐Ginsburg | Roey J. Amir | Joachim O. Rädler | Roy Beck
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-11-01)
Field: Materials Science — Biomaterials

Self-Assembly of Tunable Intrinsically Disordered Peptide Amphiphiles Abstract Intrinsically disordered peptide amphiphiles (IDPAs) present a novel class of synthetic conjugates that consist of short hydrophilic polypeptides anchored to hydrocarbon chains. These hybrid polymer-lipid block constructs spontaneously self-assemble into dispersed nanoscopic aggregates or ordered mesophases in aqueous solution due to hydrophobic interactions. Yet, the possible sequence variations and their influence on the self-assembly structures is vast and have hardly been explored. Here, we measure the nanoscopic self-assembled structures of four IDPA systems that differ by their amino acid sequence. We show that permutations in the charge pattern along the sequence remarkably alter the headgroup conformation and consequently alters the pH-triggered phase transitions between spherical, cylindrical micelles and hexagonal condensed phases. We demonstrate that even a single amino acid mutation is sufficient to tune structural transitions in the condensed IDPA mesophases, while peptide conformations remain unfolded and disordered. Furthermore, alteration of the peptide sequence can render IDPAs to become susceptible to enzymatic cleavage and induces enzymatically activated phase transitions. These results hold great potential for embedding multiple functionalities into lipid nanoparticle delivery systems by incorporating IDPAs with desired properties. Peptide ; Micelle ; Amphiphile ; Sequence (biology) ; Nanoscopic scale ; Peptide sequence ; Self-assembly ; Aqueous solution ; Phase transition ; Phase (matter) ; Chemistry ; Materials science ; Crystallography ; Polymer ; Nanotechnology ; Biophysics ; Copolymer ; Organic chemistry ; Biochemistry ; Physics Supramolecular Self-Assembly in Materials ; RNA Interference and Gene Delivery ; Polydiacetylene-based materials and applications
Authors: Wei-Tse Hsu | Dominique Ramirez | Tarek Sammakia | Zhongping Tan | Michael R. Shirts
Source: ChemRxiv (preprint, 2022-03-01)
Field: Chemistry — Organic Chemistry

Identifying signatures of proteolyticstability and monomeric propensity inO-glycosylated insulin using molecularsimulation Insulin has been commonly adopted as a peptide drug to treat diabetes given its ability to facilitate the uptake of glucose from the blood. The development of oral insulin remains elusive over decades owing to its susceptibility to the enzymes in the gastrointestinal tract and poor permeability through the intestinal epithelium upon dimerization. Recent experimental studies have revealed that certain O-linked glycosylation patterns could enhance insulin’s proteolytic stability and reduce its dimerization propensity, but the understanding of such phenomena at the molecular level is still evasive. To address this challenge, we propose and test several structural determinants that could potentially in uence insulin’s proteolytic stability and dimerization propensity. We used these as the metrics to assess the properties of interest from 10 s aggregate molecular dynamics of each of 12 targeted insulin glyco-variants from multiple wild-type crystal structures. We found that glycan-involved hydrogen bonds and glycan-dimer occlusion were useful metrics predicting the proteolytic stability and dimerization propensity of insulin, as was in part the solvent accessible surface area of proteolytic sites, while other plausible metrics were not generally predictive. This work helps better explain how O-linked glycosylation in uences the proteolytic stability and monomeric propensity of insulin, illuminating a path towards rational molecular design of insulin glycoforms. Insulin ; Proteolytic enzymes ; Glycan ; Glycosylation ; Chemistry ; Biochemistry ; Glycoprotein ; Computational biology ; Biology ; Enzyme ; Endocrinology Carbohydrate Chemistry and Synthesis ; Glycosylation and Glycoproteins Research ; Enzyme Production and Characterization
Authors: Enguo Ju | Mengran Peng | Yuqin Wang | Shixian Lv | Dan Shao | Haixia Wang | Yu Tao | Yue Zheng | Mingqiang Li
Source: Research Square (preprint, 2022-08-09)
Field: Materials Science — Materials Chemistry

Dual-responsive disassembly of core-shell nanoparticles with self-supplied H2O2 and autocatalytic Fenton reaction for enhanced chemodynamic therapy Autocatalysis ; Fenton reaction ; Chemistry ; Dual (grammatical number) ; Core (optical fiber) ; Nanoparticle ; Biophysics ; Shell (structure) ; Chemical engineering ; Nanotechnology ; Hydrogen peroxide ; Materials science ; Catalysis ; Biochemistry ; Biology ; Engineering ; Composite material ; Art Advanced Nanomaterials in Catalysis ; Nanoplatforms for cancer theranostics ; Advanced Photocatalysis Techniques
Authors: D. A. Malcolm | Laia Vilà‐Nadal
Source: ChemRxiv (preprint, 2022-09-08)
Field: Materials Science — Materials Chemistry

First steps in the inverse design of porous metal oxide materials: lacunary WellsDawson anion Porous metal oxide materials have been obtained from a ring-shaped macrocyclic polyoxometalate structural building unit, [P8W48O184]40−. This is tungsten oxide building block with an integrated "pore" of 1 nm in diameter that, connected with transition metal linkers, is able to assemble zero to three-dimensional frameworks. Our investigation has been centered in the well-known [P2W18O62]6- Wells-Dawson structure, as well as its lacunary derivatives [P2W12O48]14-. Our aim is to predict new building blocks for ring-shaped porous material, hence we have constructed a few dozen different POMs, largely differing in their heteroatom (X) content, and have determined its electron densities, electronic and reduction/oxidation energies, and HOMO-LUMO gaps, the last of which gives at least tentative information surrounding the frameworks stability. Lacunary function ; Polyoxometalate ; Heteroatom ; Oxide ; Materials science ; Porosity ; Ring (chemistry) ; Metal ; Crystallography ; Transition metal ; Nanotechnology ; Chemical engineering ; Chemistry ; Metallurgy ; Composite material ; Mathematics ; Organic chemistry ; Pure mathematics Polyoxometalates: Synthesis and Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Advanced Nanomaterials in Catalysis
Authors: S. G. Menshikova | N. M. Chtchelkatchev | V. V. Brazhkin
Source: arXiv (Cornell University) (preprint, 2022-11-07)
Field: Materials Science — Materials Chemistry

Solidification of the Glass-Forming Al86Ni2Co6Gd6 Melt under High Pressure High pressures allow the synthesis of new metastable compounds that remain intact for a sufficiently long time at normal conditions. Until now, it has not been fully understood how pressure, glass-forming ability and solidification of liquids are interconnected. We have investigated the structure of the glass-forming eutectic alloy Al86Ni2Co6Gd6 obtained by rapid cooling from the melt having a temperature of 1800 K under a pressure of 10 GPa. X-ray diffraction analysis and electron microscopy show that the samples are homogeneous and dense. The structure is finely dispersed. New stable crystalline phases with cubic (cP4/2) and tetragonal (tI26/1) structures are formed in the alloy. The studies have shown that the average microhardness of the samples obtained at 10 GPa is almost 2 times higher than that of the original sample at atmospheric pressure and is about 1700 MPa. To understand the results, we used ab initio molecular dynamics and studied how the melt changes with pressure. It is shown that at a temperature of 1800 K, high pressure increases the concentration of icosahedral clusters in the melt so that at 10 GPa atoms inside the icosahedra form a percolation cluster, while at atmospheric pressure they do not. Thus, the glass-forming ability of a melt increases at high pressure strongly influencing solidification processes. Materials science ; Metastability ; Eutectic system ; Icosahedral symmetry ; Alloy ; Atmospheric pressure ; Tetragonal crystal system ; Diffraction ; Cluster (spacecraft) ; Crystallography ; Thermodynamics ; Chemical physics ; Metallurgy ; Chemistry ; Crystal structure ; Optics Material Dynamics and Properties ; Metallic Glasses and Amorphous Alloys ; Glass properties and applications
Authors: IDONGESIT MBONU | OLUSEGUN ABIOLA | HAMZAH BAWA
Source: TURKISH JOURNAL OF CHEMISTRY (article, 2022-01-01)
Field: Chemistry — Inorganic Chemistry

Homonuclear nickel(II) metal-organic framework-type supramolecule: adsorption and emission properties Coordination-driven self-assembly of nickel (II) ions with equimolar amounts of 1, 10 phenanthroline, and benzoic acid was used to create homonuclear nickel (II) MOF-type supramolecule. Single crystal X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, photoluminescence measurement, FT-IR, UV-visible spectroscopy, and nitrogen physisorption measurement were used to characterize the compound. The single crystal X-ray diffraction study reveals that the synthesized compound is two-dimensional with pores in the structure. The homonuclear nickel (II) MOF-type supramolecule crystallized in a triclinic crystal system, with space group P-1 (No.2) and unit cell parameters a = 9.2053(4) Ǻ, b = 13.2964(5) Ǻ, c = 15.8998(6) Ǻ, α = 66.296(2) °, β = 89.400(2) °, γ = 89.441(2) °. The crystal structure result shows ?- ? and intermolecular interactions between adjacent 1, 10-phenanthroline molecules. DSC result showed a gradual decomposition confirming thermal stability of the compound. The emission (468 nm) spectrum result shows energy peaks of a typical multiphonon phase, indicating luminescence process. The surface topology and single absorption maximum at 308 nm reveal formation of a distorted octahedral structure. Brunauer?Emmett?Teller and Langmuir surface area results 383.741 and 975.830 m2g?1, respectively, indicate high adsorption capacity. Langmuir isotherm model result of the compound shows an efficient adsorption property for storing energy. The excellent nickel (II) MOF-type supramolecule adsorption capacity and emission property opened the door to its use in energy storage applications especially in photovoltaic cells. Chemistry ; Nickel ; Triclinic crystal system ; Crystallography ; Homonuclear molecule ; Crystal structure ; Molecule ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Molecular Sensors and Ion Detection ; Supramolecular Self-Assembly in Materials
Authors: Zhou Wang | Ligang Wang | Hongfa Liu | Qi Yao | Xiaolong Li | Xiaolong Wang
Source: Highlights in Science Engineering and Technology (article, 2022-12-13)
Field: Materials Science — Materials Chemistry

Study on CO2 corrosion behavior and protection technology of gas storage injection production well casing Wen 23 depleted gas reservoir gas storage is the largest underground gas storage in central and eastern China. It shoulders the important tasks of peak shaving, emergency gas supply and smooth operation of pipelines in the natural gas market in central and eastern China.During the construction period of the gas reservoir, a series of anti-corrosion measures, such as high-efficiency annular anti-corrosion protective fluid, have been designed, taking all kinds of corrosion risks of injection and production well casing into full consideration, and the anti-corrosion effect is remarkable.However, after the phase I project was constructed and put into operation, it was found that some injection and production wells had obvious leakage of annulus protection fluid. Based on the identification results of "three aspects and eleven leakage paths", it is believed that the leakage of tubing threads and packers is the main leakage path of annulus protection fluid.The natural gas produced by the original component detection of the gas reservoir contains a small amount of CO2, which may cause corrosion perforation to the downhole casing under certain circumstances.Through the corrosion perforation experiment on P110 steel selected for injection production well casing, combined with electrochemical test and surface analysis and other corrosion characterization methods, the anti-corrosion coating design for Wen 23 gas storage is completed.The research results show that the corrosion inhibition efficiency of the new salt resistant anti-corrosion coating is more than 80%, the electrochemical slow-release efficiency is more than 85%, and the anti-corrosion effect is outstanding. It can provide a strong technical guarantee for the safe, stable and stable operation of the injection production well of the gas storage. Casing ; Corrosion ; Leakage (economics) ; Petroleum engineering ; Natural gas ; Perforation ; Annulus (botany) ; Completion (oil and gas wells) ; Materials science ; Pipeline transport ; Coating ; Metallurgy ; Environmental science ; Waste management ; Engineering ; Composite material ; Environmental engineering Corrosion Behavior and Inhibition ; Hydrogen embrittlement and corrosion behaviors in metals ; Concrete Corrosion and Durability
Authors: Hua Fu | Huiyuan Chen | Weijun Song
Source: Research Square (preprint, 2022-12-02)
Field: Chemistry — Inorganic Chemistry

Efficient ZIF-67 alginate composite hydrogel material and its application to enhanced copper (II) adsorption from aqueous solutions Abstract Metal-organic framework materials(ZIF-67) were loaded on Sodium alginate/polyvinyl(PVA/SA) hydrogel by in situ growth method for adsorption of heavy metal Cu (II). The structure of hydrogels composited with MOFs and polymers was designed to improve the poor mechanical properties of natural polymer gel materials and the inconvenience of powdered MOFs materials in practical applications. Synthesized hydrogel spheres were characterized by FT-IR, SEM, XRD, XPS, etc. The adsorption results showed that the optimum adsorption process of Cu (II) pH was 5.0. The adsorption kinetics and isotherm suggest that the adsorption process follows the Freundlich isotherm and the pseudo-second-order models. The experimental maximum adsorption capacity was 128.4 mg/g, 3.3 times and 1.8 times higher than ordinary SA and PVA/SA hydrogel spheres. The selectively experimental results show that PVA/SA@ZIF-67 exhibits better adsorption performance (especially for ion Cu(II), Pb(II) ) and it also indicates that PVA/SA@ZIF-67 has application potential when applied in some specific fields of wastewater treatment. More importantly, PVA/SA@ZIF-67 exhibited exceptional mechanical stability and showed excellent recycling capability in the cyclic adsorption process. Adsorption ; Aqueous solution ; Self-healing hydrogels ; Chemical engineering ; Materials science ; Freundlich equation ; Composite number ; Polyvinyl alcohol ; Polymer ; X-ray photoelectron spectroscopy ; Metal ions in aqueous solution ; Copper ; Metal-organic framework ; Metal ; Sodium alginate ; Precipitation ; Composite material ; Polymer chemistry ; Chemistry ; Organic chemistry ; Sodium ; Metallurgy Metal-Organic Frameworks: Synthesis and Applications ; Graphene and Nanomaterials Applications ; Adsorption and biosorption for pollutant removal