jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Thomas Petersen
Source: arXiv (Cornell University) (preprint, 2023-12-08)
Field: Chemistry — Physical and Theoretical Chemistry

Toward Modeling the Structure of Electrolytes at Charged Mineral Interfaces using Classical Density Functional Theory The organization of water molecules and ions between charged mineral surfaces determines the stability of colloidal suspensions and the strength of phase-separated particulate gels. In this article we assemble a density functional that measures the free energy due to the interaction of water molecules and ions near electric double layers. The model accounts for the finite size of the particles using fundamental measure theory, hydrogen-bonding between water molecules using Wertheim's statistical association theory, long-range dispersion interactions using Barker and Henderson's high temperature expansion, electrostatic correlations using a functionalized mean-spherical approximation, and Coulomb forces through the Poisson equation. These contributions are shown to produce highly correlated structures, aptly rendering the layering of counter-ions and co-ions at highly charged surfaces, and permitting the solvation of ions and surfaces to be measured by a combination of short-ranged association and long-ranged attraction. The model is tested in a planar geometry near soft, charged surfaces to reproduce the structure of water near graphene and mica. For mica surfaces, explicitly representing the density of the outer oxygen layer of the exposed silica tetrahedra in the domain permits water molecules to hydrogen-bind to the surface. When electrostatic interactions are included, water molecules assume a hybrid character, being accounted for implicitly in the dielectric constant but explicitly otherwise. The disjoining pressure between approaching like-charged surfaces is calculated, demonstrating the model's ability to probe pressure oscillations that arise during the expulsion of ions and water layers from the interfacial gap, and predict the strong inter-attractive stresses that form at narrow interfacial spacing when the surface charge is overscreened. Chemical physics ; Ion ; Density functional theory ; Solvation ; Molecule ; Disjoining pressure ; Electrostatics ; Electrolyte ; Chemistry ; Charge density ; van der Waals force ; Dielectric ; Mica ; Ionic bonding ; Materials science ; Computational chemistry ; Wetting ; Physics ; Physical chemistry ; Composite material ; Quantum mechanics Electrostatics and Colloid Interactions ; Iron oxide chemistry and applications ; Geophysical and Geoelectrical Methods
Authors: Fenfang Li
Source: Zeitschrift für Kristallographie - New Crystal Structures (article, 2023-09-14)
Field: Chemistry — Inorganic Chemistry

Crystal structure of bis(dimethylammonium) poly[(μ<sub>4</sub>-1,1′-(1,4-phenylenebis(methylene))bis(1H-pyrazole-3,5-dicarboxylato))-κ<sup>6</sup> <i>O</i> <sup>1</sup>, <i>N</i> <sup>2</sup>:<i>O</i> <sup>2</sup>:<i>O</i> <sup>3</sup>:<i>O</i> <sup>1</sup>′,<i>N</i> <sup>2</sup>′]nickel (II)], C<sub>22</sub>H<sub>26</sub>N<sub>6</sub>NiO<sub>8</sub> Abstract C 22 H 26 N 6 NiO 8 , monoclinic, P 2 1 / n (no. 14), a = 10.9372(7) Å, b = 10.4567(6) Å, c = 11.7618(7) Å, β = 116.5552(19)°, V = 1203.25(13) Å 3 , Z = 2, R gt ( F ) = 0.0406, wR ref ( F 2 ) = 0.1089, T = 297(2) K. Monoclinic crystal system ; Methylene ; Crystallography ; Crystal structure ; Crystal (programming language) ; Chemistry ; Stereochemistry ; Medicinal chemistry Metal-Organic Frameworks: Synthesis and Applications ; Metal complexes synthesis and properties ; Magnetism in coordination complexes
Authors: Chelsea N. Bridgmohan | Lichang Wang
Source: ChemRxiv (preprint, 2023-04-21)
Field: Chemistry — Organic Chemistry

DFT studies of proton transfer of 2, 4-dihydroxybenzoic acid derivatives In this work, the proton transfer and photophysical properties of 2,4-dihydroxybenzoic acid and its chlorinated and brominated derivatives were studied using Density Functional Theory (DFT) to understand the proton transfer mechanism of these molecules as matrices in matrix-assisted laser desorption-ionization (MALDI). Structures, IR, UV-Vis, and fluorescence spectra were obtained together with the energies of frontier orbitals from DFT and time-dependent DFT calculations. In addition, the proton affinity (PA) and gas phase acidity (GPA) of the molecules were determined to understand the heavy atom substitution effect. Upon substitution of Cl and Br, the UV-Vis absorption at ~330 nm increases with heavy atom substitutions. While no apparent change in the OH bond strength at the ground state, it is substantially weakened upon electronic excitation at both the first singlet and triplet excited states under heavy atom substitution. These results demonstrate that both the UV-Vis absorption and intersystem crossing play important roles in facilitating proton transfer in heavy atom substitution of 2,4-dihydroxybenzoic acid. Chemistry ; Intersystem crossing ; Density functional theory ; Excited state ; Singlet state ; Photochemistry ; Protonation ; Proton ; Molecule ; Absorption spectroscopy ; Ground state ; Computational chemistry ; Atomic physics ; Ion ; Organic chemistry Free Radicals and Antioxidants ; Photochemistry and Electron Transfer Studies ; Analytical Chemistry and Chromatography
Authors: Michael Seifert | Tomáš Rauch | Miguel A. L. Marques | Silvana Botti
Source: arXiv (Cornell University) (preprint, 2023-05-24)
Field: Materials Science — Materials Chemistry

Structure prediction and characterization of CuI-based ternary $p$-type transparent conductors Zincblende copper iodide has attracted significant interest as a potential material for transparent electronics, thanks to its exceptional light transmission capabilities in the visible range and remarkable hole conductivity. However, remaining challenges hinder the utilization of copper iodide's unique properties in real-world applications. To address this, chalcogen doping has emerged as a viable approach to enhance the hole concentration in copper iodide. In search of further strategies to improve and tune the electronic properties of this transparent semiconductor, we investigate the ternary phase diagram of copper and iodine with sulphur or selenium by performing structure prediction calculations using the minima hopping method. As a result, we find 11 structures located on or near the convex hull, 9 of which are unreported. Based on our band structure calculations, it appears that sulphur and selenium are promising candidates for achieving ternary semiconductors suitable as $p$-type transparent conducting materials. Additionally, our study reveals the presence of unreported phases that exhibit intriguing topological properties. These findings broaden the scope of potential applications for these ternary systems, highlighting the possibility of harnessing their unique electronic characteristics in diverse electronic devices and systems. Ternary operation ; Semiconductor ; Materials science ; Doping ; Electronic structure ; Copper ; Characterization (materials science) ; Conductivity ; Iodide ; Chalcogen ; Band gap ; Nanotechnology ; Chemical physics ; Optoelectronics ; Crystallography ; Computer science ; Inorganic chemistry ; Computational chemistry ; Chemistry ; Physical chemistry ; Metallurgy Copper-based nanomaterials and applications ; Quantum Dots Synthesis And Properties ; Nanocluster Synthesis and Applications
Authors: Ufuk Kılıç | Yousra Traouli | Matthew Hilfiker | Khalil Bryant | Stefan Schoeche | René Feder | Christos Argyropoulos | E. F. Schubert | M. Schubert
Source: arXiv (Cornell University) (preprint, 2023-12-01)
Field: Materials Science — Surfaces, Coatings and Films

Nanocolumnar Material Platforms:Universal structural parameters revealed from optical anisotropy Nanostructures represent a frontier where meticulous attention to the control and assessment of structural dimensions becomes a linchpin for their seamless integration into diverse technological applications. By using integrative and comprehensive methodical series of studies, we investigate the evolution of the depolarization factors in the anisotropic Bruggeman effective medium approximation, that are extremely sensitive to the changes in critical dimensions of the nanostructure platforms. To this end, we fabricate spatially coherent highly-ordered slanted nanocolumns from zirconia, silicon, titanium, and permalloy on silicon substrates with varying column lengths using glancing angle deposition. In tandem, broad-spectral range Mueller matrix spectroscopic ellipsometry data, spanning from the near-infrared to the vacuum ultraviolet (0.72 eV to 6.5 eV), is analyzed with a best-match model approach based on the anisotropic Bruggeman effective medium theory. We thereby extracted the anisotropic optical properties including complex dielectric function, birefringence, and dichroism. Most notably, our research unveils a universal, material-independent inverse relationship between depolarization factors and column length. We envision that the presented universal relationship will permit accurate prediction of optical properties of nanocolumnar thin films improving their integration and optimization for optoelectronic and photonic device applications. Anisotropy ; Materials science ; Nanostructure ; Mueller calculus ; Silicon ; Birefringence ; Ellipsometry ; Optoelectronics ; Photonics ; Optics ; Thin film ; Nanotechnology ; Physics Optical Coatings and Gratings ; Optical Polarization and Ellipsometry
Authors: Polina A. Morozova | Semyon D. Shraer | Artem D. Dembitskiy | Nikita Luchinin | С. С. Федотов
Source: Acta Crystallographica Section A Foundations and Advances (article, 2023-08-22)
Field: Materials Science — Surfaces, Coatings and Films

Charge-compensation mechanism and structural evolution in metal-ion battery cathodes studied by XAS and XRD X-ray absorption spectroscopy ; Cathode ; Materials science ; Mechanism (biology) ; Battery (electricity) ; Compensation (psychology) ; Metal ; Charge (physics) ; Ion ; Chemical physics ; Metallurgy ; Chemistry ; Physics ; Power (physics) ; Optics ; Physical chemistry ; Absorption spectroscopy ; Thermodynamics ; Psychology Electron and X-Ray Spectroscopy Techniques ; Advancements in Battery Materials ; Extraction and Separation Processes
Authors: Mr. Walke Sudhir Tukaram | Rajnikant Patel
Source: Journal for ReAttach Therapy and Developmental Diversities (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

“An Efficient Synthesis of Hybrid Chalcone And Acetyl Pyrazoline Derivatives As Potent Antimycobacterial And Antimicrobial Agents” The continuous increase of bacteria and viruses that are able to withstand antibiotics is a major problem for human health across the world. We must find new ways to treat these infections immediately. There is an urgent need to investigate new chemical scaffolds and hybrid molecules that may provide improved effectiveness, as many widely used antibiotics and antimycobacterial medicines are losing some of their effectiveness. To enhance the therapeutic benefits of many bioactive substances, one potential approach to drug design is to synthesize hybrid molecules that integrate their pharmacophores. Particularly in the fields of antibacterial and antimycobacterial therapies, hybrid chalcone and acetyl pyrazoline derivatives have attracted a lot of interest owing to their varied biological activities. Chalcones are naturally occurring chemicals that belong to the flavonoid family. They have shown a broad range of biological actions, such as antibacterial, anti-inflammatory, antioxidant, anticancer, and antimalarial characteristics. They can be easily modified chemically and used to produce new derivatives due to their very adaptable α, β-unsaturated ketone system and simple chemical structure. The capacity of chalcones to bind with DNA of bacteria and fungi, block enzymes, and disrupt microbial cell membranes is the main explanation for their biological activity. Chalcones are thought to be great starting points for novel antimicrobial agents because of their structural flexibility and wide range of activities.(Cheng et al., 2020) Conversely, pyrazolines are heterocyclic molecules with five carbon atoms that have shown strong biological activity, such as antibacterial, antifungal, anticancer, and anti-inflammatory properties. The capacity of pyrazoline derivatives to suppress the development of infectious microbes including mycobacteria, fungus, and bacteria has led to a surge in their popularity. Chalcone scaffolds may have their antibacterial action amplified by adding a pyrazoline component to them. In particular, acetyl pyrazoline derivatives offer promising new avenues for antimicrobial research due to their enhanced effectiveness against a wide range of resistant bacterial strains. Chalcone ; Antimycobacterial ; Antimicrobial ; Chemistry ; Combinatorial chemistry ; Pyrazoline ; Organic chemistry ; Mycobacterium tuberculosis ; Medicine ; Tuberculosis Synthesis and biological activity ; Multicomponent Synthesis of Heterocycles
Authors: Antonio Togni
Source: CHIMIA International Journal for Chemistry (article, 2023-10-25)
Field: Chemistry — Physical and Theoretical Chemistry

Do You Speak Chemistry? This article is a broad personal reflection about the language of chemistry, deriving from decades of experience in both research and teaching. The three levels of thought as represented by the Johnstone triangle, a critical attitude towards systematic nomenclature, the concept of pure substance, and the central significance of structural formulas as the most prominent form of representation in chemistry, are the main topics discussed. The chemical transliteration of the Platonic solids is presented as a mean of expression unique to chemistry. Representation (politics) ; Transliteration ; Expression (computer science) ; Chemistry ; Reflection (computer programming) ; Chemical nomenclature ; Epistemology ; Mathematics education ; Computer science ; Organic chemistry ; Psychology ; Philosophy ; Natural language processing ; Programming language ; Political science History and advancements in chemistry ; Various Chemistry Research Topics
Authors: Haoyang Liu | Jianing Zhu
Source: MedScien (article, 2023-06-01)
Field: Chemistry — Organic Chemistry

Introduction of Retrosynthetic Analysis and Guidelines Application of Analyze Molecules Retrosynthesis is vital in breaking down complex target organic compounds based on known reactions. It serves as the reverse process of synthesis, which provides an alternative thinking path to aim for finding possibilities of synthesis reactions. In addition, different synthesis pathways can be discovered in the process of utilizing the retrosynthesis technology. It introduces the history of retrosynthetic synthesis using deoxygenation patterns which are different from disconnections, guidelines, and ordinary. In this work, a complete introduction to retrosynthesis and guidelines for people to apply retrosynthesis are well supported and introduced. The purpose of this paper is to serve as a detailed tutorial and offers specific rules for readers to learn. Retrosynthetic analysis ; Process (computing) ; Computer science ; Deoxygenation ; Engineering ; Programming language ; Chemistry Chemical Synthesis and Reactions ; Asymmetric Hydrogenation and Catalysis ; Chemical Synthesis and Analysis
Authors: Erik Weiand | F. Rodríguez-Ropero | Yuri Roiter | Peter König | Stefano Angioletti‐Uberti | Daniele Dini | James P. Ewen
Source: ChemRxiv (preprint, 2023-06-02)
Field: Chemistry — Organic Chemistry

Effects of Surfactant Adsorption on the Wettability and Friction of Biomimetic Surfaces The properties of solid-liquid interfaces can be markedly altered by surfactant adsorption. Here, we use molecular dynamics simulations to study the adsorption of ionic surfactants at the interface between water and heterogeneous solid surfaces with randomly arranged hydrophilic and hydrophobic regions, which mimic the surface properties of human hair. We use the coarse-grained MARTINI model to describe both the hair surfaces and surfactant solutions. We consider negatively-charged virgin and bleached hair surface models with different grafting densities of neutral octadecyl and anionic sulfonate groups. The adsorption of cationic cetrimonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) surfactants from water are studied above the critical micelle concentration. The simulated adsorption isotherms suggest that cationic surfactants adsorb to the surfaces via a two-stage process, initially forming monolayers and then bilayers at high concentrations, which is consistent with previous experiments. Anionic surfactants weakly adsorb via hydrophobic interactions, forming only monolayers on both virgin and medium bleached hair surfaces. We also conduct non-equilibrium molecular dynamics simulations, which show that applying cationic surfactant solutions to bleached hair successfully restores the low friction seen with virgin hair. Friction is controlled by the combined surface coverage of the grafted lipids and the adsorbed CTAB molecules. Treated surfaces containing monolayers and bilayers both show similar friction, since the latter are easily removed by compression and shear. Further wetting MD simulations show that bleached hair treated with CTAB increases the hydrophobicity to similar levels seen for virgin hair. Treated surfaces containing CTAB monolayers with the tailgroups pointing predominantly away from the surface are more hyrophobic than bilayers due to the electrostatic interactions between water molecules and the exposed cationic headgroups. Pulmonary surfactant ; Adsorption ; Monolayer ; Cationic polymerization ; Wetting ; Chemistry ; Chemical engineering ; Sodium dodecyl sulfate ; Bromide ; Critical micelle concentration ; Micelle ; Contact angle ; Organic chemistry ; Aqueous solution Surfactants and Colloidal Systems ; Advancements in Transdermal Drug Delivery ; Textile materials and evaluations
Authors: Kurt V. Mikkelsen
Source: Journal of Nanosciences Research & Reports (article, 2023-07-29)
Field: Materials Science — Materials Chemistry

Density Functional Theory Investigation on Boron-Subphthalocyanine In this article a Density Functional Theory (DFT) description of derivatives of boron-subphthalocyanines (SubPc) is investigated. Investigated structures are peripherally functionalized derivatives Boron ; Density functional theory ; Materials science ; Chemistry ; Computational chemistry ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Organic Chemistry Cycloaddition Reactions ; Organic and Molecular Conductors Research
Authors: Kanchan Sarkar | Darius Hübner | Daniel Stottmeister | Axel Groß
Source: ChemRxiv (preprint, 2023-10-03)
Field: Chemistry — Inorganic Chemistry

Unraveling the Intricacies of Surface Salt Formation on Mg(0001): Implications for Chloride-Ion Batteries We present a density functional theory study of the initial steps of chlorine deposition on the Mg(0001) surface. Such processes occur in chloride-ion batteries in which lithium and magnesium are used as anode materials. In addition, it is also of fundamental interest, as halide adsorption on metal electrodes is an important process in interfacial electrochemistry. We discuss the adsorption properties and determine the stable adsorption structures, both with respect to the free chlorine molecule but also as a function of the electrode potential. We find indications of the immediate formation of the MgCl2 surface salt structure upon exposure of Cl to a Mg surface. These findings are discussed with respect to the conversion of the Mg anode to a MgCl2 configuration which provides the thermodynamical driving force for the discharge of a Cl-ion battery. Anode ; Adsorption ; Chlorine ; Electrochemistry ; Halide ; Inorganic chemistry ; Chloride ; Salt (chemistry) ; Magnesium ; Ion ; Electrode ; Chemistry ; Density functional theory ; Battery (electricity) ; Molecule ; Lithium (medication) ; Metal ; Chemical engineering ; Materials science ; Computational chemistry ; Physical chemistry ; Organic chemistry ; Thermodynamics Inorganic Fluorides and Related Compounds ; Ammonia Synthesis and Nitrogen Reduction ; Advancements in Battery Materials
Authors: Hao Nguyen | Grant J. Dixon | Florence Y. Dou | Shaun Gallagher | Stephen Gibbs | Dylan M. Ladd | Emanuele Marino | Justin C. Ondry | James P. Shanahan | Eugenia S. Vasileiadou | Stephen Barlow | Daniel R. Gamelin | David Ginger | David M. Jonas | Mercouri G. Kanatzidis | Seth R. Marder | Daniel Morton | Christopher B. Murray | Jonathan S. Owen | Dmitri V. Talapin | Michael F. Toney | Brandi M. Cossairt
Source: ChemRxiv (preprint, 2023-05-08)
Field: Materials Science — Materials Chemistry

Design rules for obtaining narrow luminescence from semiconductors made in solution Solution processed semiconductors are in demand for present and next-generation optoelectronic technologies ranging from displays to quantum light sources because of their scalability and ease of integration into devices with diverse form factors. One of the central requirements for semiconductors used in these applications is a narrow photoluminescence (PL) linewidth. Narrow emission linewidths are needed to ensure both color and single-photon purity, raising the question of what design rules are needed to obtain narrow emission from semiconductors made in solution. In this review we first examine the requirements for colloidal emitters for a variety of applications including light-emitting diodes, photodetectors, lasers, and quantum information science. Next, we will delve into the sources of spectral broadening, including “homogeneous” broadening from dynamical broadening mechanisms in single-particle spectra, heterogeneous broadening from static structural differences in ensemble spectra, and spectral diffusion. Then, we compare the current state of the art in terms of emission linewidth for a variety of colloidal materials including II-VI quantum dots (QDs) and nanoplatelets, III-V QDs, alloyed QDs, metal-halide perovskites including nanocrystals and 2D structures, doped nanocrystals, and, finally, as a point of comparison, organic molecules. We end with some conclusions and connections, including an outline of promising paths forward. Laser linewidth ; Photoluminescence ; Optoelectronics ; Materials science ; Quantum dot ; Semiconductor ; Nanocrystal ; Diode ; Nanotechnology ; Laser ; Optics ; Physics Quantum Dots Synthesis And Properties ; Perovskite Materials and Applications ; Chalcogenide Semiconductor Thin Films
Authors: Ryan P. King | Jenny Y. Yang
Source: ChemRxiv (preprint, 2023-09-19)
Field: Chemistry — Organic Chemistry

Modular Preparation of Cationic Bipyridines and Azaarenes via C–H Activation Bipyridines are ubiquitous in organic and inorganic chemistry because of their redox and photochemical properties and their utility as ligands to transition metals. Cationic substituents on bipyridines and azaarenes are valuable as powerful electron-withdrawing functionalities that also enhance solubility in polar solvents, but there are no general methods for direct functionalization. A versatile method for the preparation of trimethylammonium- and triarylphosphonium-substituted bipyridines and azaheterocycles is disclosed. This methodology showcases a C–H activation of pyridine N-oxides that enables a highly modular and scalable synthesis of a diverse array of cationically charged azaarenes. The addition of trimethylammonium functionalities on bipyridine derivatives resulted in more anodic reduction potentials (up to 700 mV) and increased electrochemical reversibility compared to the neutral unfunctionalized bipyridine. Additonally, metallation of 4-triphenylphosphinated biquinoline to make the corresponding Re(CO)3Cl complex resulted in reduction potentials 400 mV more anodic than the neutral derivative. Cationic polymerization ; Chemistry ; Pyridine ; Combinatorial chemistry ; Bipyridine ; Redox ; Electrochemistry ; Anode ; Solubility ; Organic chemistry ; Electrode ; Physical chemistry Catalytic C–H Functionalization Methods ; Radical Photochemical Reactions ; Chemical Synthesis and Analysis