jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Qiwen Pang | Li Yang | Xin Xie | Jie Tang | Qian Liu | Cheng Peng | Xiang Li | Bo Han
Source: Frontiers in Chemistry (review, 2022-10-21)
Field: Chemistry — Organic Chemistry

The emerging role of radical chemistry in the amination transformation of highly strained [1.1.1]propellane: Bicyclo[1.1.1]pentylamine as bioisosteres of anilines Bicyclo[1.1.1]pentylamines (BPCAs), emerging as sp<sup>3</sup>-rich surrogates for aniline and its derivatives, demonstrate unique structural features and physicochemical profiles in medicinal and synthetic chemistry. In recent years, compared with conventional synthetic approaches, the rapid development of radical chemistry enables the assembly of valuable bicyclo[1.1.1]pentylamines scaffold directly through the amination transformation of highly strained [1.1.1]propellane. In this review, we concisely summarize the emerging role of radical chemistry in the construction of BCPAs motif, highlighting two different and powerful radical-involved strategies including <i>C</i>-centered and <i>N</i>-centered radical pathways under appropriate conditions. The future direction concerning BCPAs is also discussed at the end of this review, which aims to provide some inspiration for the research of this promising project. Propellane ; Bicyclic molecule ; Chemistry ; Amination ; Aniline ; Combinatorial chemistry ; Nanotechnology ; Organic chemistry ; Materials science ; Catalysis Radical Photochemical Reactions ; Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods
Authors: Chandan Maurya | Sangeeta Bajpai
Source: Journal of Applied Science and Education (JASE) (article, 2022-03-01)
Field: Chemistry — Organic Chemistry

Biological Applications of Metal Complexes of Dithiocarbamates Dithiocarbamates are organosulphur ligands and form chelate compounds with metals. Their uses are reported in the field of accelerating vulcanization, pesticide, material science, organic synthesis, etc. Recent research demonstrated the potential of metal complexes of these ligands as good antifungal, antibacterial, and antitumor agents. Dithiocarbamate complexes have also been reported to use as a plasmonic sensor, as an inhibitor of proteasome, and for antioxidant and antileishmanial activity. This brief review presents the biological activities of metal complexes of dithiocarbamate. Dithiocarbamate ; Chelation ; Antifungal ; Chemistry ; Metal ; Combinatorial chemistry ; Vulcanization ; Antioxidant ; Organic chemistry ; Biology ; Microbiology Organometallic Compounds Synthesis and Characterization ; Metal complexes synthesis and properties ; Synthesis and Reactivity of Sulfur-Containing Compounds
Authors: Zainab K Al-Khazragie | Bushra K Al-Salami | Adnan J. M Al-Fartosy
Source: International Journal of Drug Delivery Technology (article, 2022-06-25)
Field: Chemistry — Organic Chemistry

Synthesis, Characterization, and Antioxidant, Antimicrobial and Toxic Properties of Novel Δ2 -1,3,4-thiadiazoline and Δ2 -1,3,4-selenadiazoline Derivatives Two new series of N-(4-acetyl-5-aryl-4,5-dihydro-1,3,4-thiadiazol-2-yl)acetamide and N-(4-acetyl-5-aryl-4,5-dihydro1,3,4-selenadiazol-2-yl)acetamide compounds (where aryl = 4-nitrophenyl, 4-hydroxy-3-methoxyphenyl, 3-ethoxy-4- hydroxyphenyl, 2-chloroquinolinyl, and 6-chloro-4-oxo-4H-chromenyl) were synthesized in good yields by heterocyclization of thiosemicarbazones (TSCs) and selenosemicarbazones (SSCs) with acetic anhydride, respectively. The new TSCs and SSCs compounds was prepared by condensation reaction of thiosemicarbazide and Selenosemicarbazide with aromatic aldehydes in acidic medium. The structures of newly synthesized 1,3,4-thiadiazoline (TDZs) and 1,3,4-selenadiazoline (SDZs) derivatives were characterized by the analytical and spectroscopic method such as IR, 1 H NMR, 13C NMR, mass spectra and elemental analysis. The purity of compound and evaluation of Rf value were determined by TLC. The toxicity of new compounds was assayed via the determination of their LD50 value by using Dixon’ s up and down method. The antibacterial activity of 1,3,4-thiadiazoline and 1,3,4-selenadiazoline compounds were tested in vitro against Staphylococcus aureus, Bacillus, Escherichia coli and Pseudomonas aeruginosa. Finally, antioxidant efficiency of all compounds were detected according to β-carotene bleaching method. Acetamide ; Acetic anhydride ; Chemistry ; Aryl ; Antimicrobial ; Carbon-13 NMR ; Proton NMR ; Antioxidant ; Nuclear chemistry ; Benzimidazole ; Elemental analysis ; Organic chemistry Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Structural and Chemical Analysis of Organic and Inorganic Compounds
Authors: Funda Tay | Murat Duran | İsmail Kayağil | Leyla Yurttaş | Gamze Göğer | Fatih Göğer | Fati̇h Demi̇rci̇ | Şeref Demirayak
Source: Brazilian Journal of Pharmaceutical Sciences (article, 2022-01-01)
Field: Chemistry — Organic Chemistry

Synthesis, antimicrobial and antioxidant activities of pyridyl substituted thiazolyl triazole derivatives In this present study, 63 different 5-[4-methyl-2-(pyridin-3/4-yl)thiazole-5-yl]-4-substituted-3-substituted benzylthio-4H-1,2,4-triazole derivatives were synthesized, and evaluated for their in vitro antimicrobial activity against various human pathogenic microorganisms and antioxidant activity. The derivatives were synthesized in a multi-step synthesis procedure including triazole and thiazole ring closure reactions, respectively. The synthesized derivatives (A1-24; B1-39) were screened for their antibacterial, antifungal, and antioxidant activities compared to standard agents. The derivatives possessing 3-pyridyl moiety particularly exhibited relatively high antibacterial activity (MIC= < 3.09-500 µg/mL) against Gram-positive bacteria, and compounds possessing 4-pyridyl moiety showed remarkable antioxidant activity. Thiazole ; Antimicrobial ; Moiety ; Chemistry ; Antioxidant ; Antifungal ; Triazole ; Antibacterial activity ; 1,2,4-Triazole ; Combinatorial chemistry ; In vitro ; Bacteria ; Organic chemistry ; Stereochemistry ; Biochemistry ; Microbiology ; Biology Synthesis and biological activity ; Click Chemistry and Applications ; Multicomponent Synthesis of Heterocycles
Authors: Dibyangana Parbat | Uttam Manna
Source: Materials Advances (article, 2022-09-27)
Field: Materials Science — Surfaces, Coatings and Films

Responsive and reactive layer-by-layer coatings for deriving functional interfaces In this review, some important designs of stimuli responsive and chemically reactive multilayer coatings were presented to display the inherent ability of such interfaces in associating different relevant, functional and bio-inspired properties. Layer (electronics) ; Materials science ; Layer by layer ; Nanotechnology ; Computer science Polymer Surface Interaction Studies ; Surface Modification and Superhydrophobicity ; Supramolecular Self-Assembly in Materials
Authors: Gustav Ferrand‐Drake del Castillo | Maria Kyriakidou | Zeynep Adali | Kunli Xiong | Rebekah L. N. Hailes | Andreas Dahlin
Source: Angewandte Chemie (article, 2022-03-15)
Field: Materials Science — Surfaces, Coatings and Films

Electrically Switchable Polymer Brushes for Protein Capture and Release in Biological Environments** Abstract Interfaces functionalized with polymers are known for providing excellent resistance towards biomolecular adsorption and for their ability to bind high amounts of protein while preserving their structure. However, making an interface that switches between these two states has proven challenging and concepts to date rely on changes in the physiochemical environment, which is static in biological systems. Here we present the first interface that can be electrically switched between a high‐capacity (&gt;1 μg cm −2 ) multilayer protein binding state and a completely non‐fouling state (no detectable adsorption). Switching is possible over multiple cycles without any regeneration. Importantly, switching works even when the interface is in direct contact with biological fluids and a buffered environment. The technology offers many applications such as zero fouling on demand, patterning or separation of proteins as well as controlled release of biologics in a physiological environment, showing high potential for future drug delivery in vivo. Nanotechnology ; Polymer ; Adsorption ; Fouling ; Protein adsorption ; Drug delivery ; On demand ; Chemistry ; Interface (matter) ; Materials science ; Biophysics ; Computer science ; Membrane ; Organic chemistry ; Biochemistry Polymer Surface Interaction Studies ; Molecular Junctions and Nanostructures ; Hydrogels: synthesis, properties, applications
Authors: G. Barriga González | J. Muñoz Espinoza
Source: Journal of the Chilean Chemical Society (article, 2022-06-01)
Field: Chemistry — Organic Chemistry

THERMODYNAMIC AND REACTIVITY ASPECT OF &amp;#946;-CYCLODEXTRINE INCLUSION COMPLEXES WITH COUMARIN DERIVATIVES In this study, the thermodynamic and reactivity characteristics of coumarin-derived ligand inclusion complexes with CD were described, in addition to the in situ reactivity of these ligands and their changes in the complex cavity. For this purpose, computational tools such as molecular docking, second order perturbative analysis (E2PERT), ONIOM2 (DFT/PM6) methods were employed to obtain the global and local reactivity indices, and thermodynamic parameters, in addition to noncovalent interaction (NCI) analysis. As a result, it can be observed that the inclusion complexes are stable and viable given the ability to form non-covalent interactions, but their formation is not spontaneous under the modeling conditions. The global and local reactivity indices show that the ligands change their chemical reactivity inside the inclusion complex, demonstrating that the studied ligands present AOX SET activity outside the cavity, and HAT activity inside the cavity, mainly the C1 and C3 ligands. Reactivity (psychology) ; Chemistry ; Coumarin ; Covalent bond ; Docking (animal) ; Ligand (biochemistry) ; Inclusion (mineral) ; Molecule ; Computational chemistry ; Molecular model ; Stereochemistry ; Combinatorial chemistry ; Organic chemistry ; Biochemistry ; Receptor Free Radicals and Antioxidants ; Photochemistry and Electron Transfer Studies ; Metal complexes synthesis and properties
Authors: Tingting Cheng | Yuying Guo | Yuxin Xie | Laibin Zhao | Ting Wang | Alan Meng | Zhenjiang Li
Source: Research Square (preprint, 2022-12-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Customizing the structure and chemical composition of ultralight carbon foams for superior microwave absorption performance Abstract Developing biomass-derived three-dimensional porous carbon materials (porous carbon foam, PCF) has become a common strategy to obtain lightweight and efficient electromagnetic microwave-absorbing materials. Without the introduction of a template and subsequent activation process, several ultra-lightweight honeycomb PCF samples were successfully prepared from dried ballonflower (DB) by simple calcination, and the calcination temperature plays a decisive role in regulating the pore size, composition and microwave absorption properties of PCF samples. Furthermore, it is worth noting that different cutting directions also affected the hole size of the PCF sample as well as the microwave absorption performances. Under the combined effects of multiple reflections and scattering of PCF porous structure, dipole polarization of abundant heterogeneous atoms and good conductive loss of carbon material, the vertical cutting sample PCF-900V exhibits optimal microwave absorption performances with the minimal reflection loss (RL min ) value of -46.95 dB at 1.46 mm thickness and the effective absorption bandwidth (EAB) value of 5.52 GHz at 1.72 mm matching thickness respectively, indicating its great potential application as a promising lightweight and efficient microwave absorbing material. Reflection loss ; Microwave ; Materials science ; Calcination ; Porosity ; Absorption (acoustics) ; Composite material ; Carbon fibers ; Discrete dipole approximation ; Scattering ; Optics ; Composite number ; Chemistry ; Organic chemistry ; Computer science ; Catalysis Electromagnetic wave absorption materials ; Advanced Antenna and Metasurface Technologies ; Flame retardant materials and properties
Authors: Frances E. Bugden | Guy J. Clarkson | Mark D. Greenhalgh
Source: European Journal of Organic Chemistry (article, 2022-12-16)
Field: Chemistry — Organic Chemistry

Lithiation‐Functionalisation of Triazoles Bearing Electron‐Withdrawing <i>N</i> ‐Substituents: Challenges and Solutions** Abstract The regioselective lithiation of 1,2,3‐triazoles provides an opportunity to introduce additional functionality, however this simple functionalisation strategy using triazoles bearing electron‐withdrawing N ‐substituents has not been investigated until now. Herein, we demonstrate that the lithiated triazole intermediates can readily decompose, even at −78 °C. In addition, lithiation‐deuteration studies reveal lithiation can take place competitively on both the triazole and the electron‐withdrawn aryl ring. Careful control of reaction conditions is therefore required to i) minimise decomposition pathways; and ii) facilitate regioselective functionalisation of the triazole. Regioselectivity ; Chemistry ; Ring (chemistry) ; Combinatorial chemistry ; Triazole ; Polar effect ; Decomposition ; Aryl ; Organic chemistry ; Catalysis Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Synthesis and Biological Evaluation
Authors: Jan Paulo T. Zaragoza | Adam R. Offenbacher | Shenshen Hu | Christine L. Gee | Zachary M. Firestein | Natalie Minnetian | Zhenyu Deng | Flora Fan | Anthony T. Iavarone | Judith P. Klinman
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-04-01)
Field: Chemistry — Physical and Theoretical Chemistry

Temporal and Spatial Resolution of a Protein Quake that Activates Hydrogen Tunneling in Soybean Lipoxygenase Abstract The enzyme soybean lipoxygenase (SLO) provides a prototype for deep tunneling mechanisms in hydrogen transfer catalysis. This work combines room temperature X-ray studies with extended hydrogen deuterium exchange experiments to detect a radiating cone of aliphatic side chains that extends from the iron active site of SLO to the protein-solvent interface. Employing eight variants of SLO, nanosecond fluorescence Stokes shifts have been measured using a probe appended to the identified surface loop. We report a remarkable identity of the enthalpies of activation for the Stokes shifts decay rates and the millisecond C-H bond cleavage step that is restricted to side chain mutants within the identified thermal network. While the role of dynamics in enzyme function has been predominantly attributed to a distributed protein conformational landscape, these new data implicate a thermally initiated, cooperative protein quake as the source of the activation of SLO. These findings indicate a direct coupling of distal protein motions surrounding the exposed fluorescent probe to active site motions controlling catalysis. Chemistry ; Active site ; Quake (natural phenomenon) ; Nanosecond ; Fluorescence ; Catalysis ; Protein dynamics ; Enzyme catalysis ; Photochemistry ; Chemical physics ; Biophysics ; Protein structure ; Crystallography ; Physics ; Biochemistry ; Optics ; Biology Photochemistry and Electron Transfer Studies ; Photosynthetic Processes and Mechanisms ; Electron Spin Resonance Studies
Authors: Sergio Moles Quintero | Michael M. Haley | Miklós Kertész | Juan Casado
Source: Angewandte Chemie (article, 2022-08-20)
Field: Chemistry — Organic Chemistry

Polycyclic Hydrocarbons from [4<i>n</i>]Annulenes: Correlation versus Hybridization Forces in the Formation of Diradicaloids Abstract The conceptual connections between [4 n ] Hückel antiaromaticity, disjoint orbitals, correlation energy, pro‐aromaticity and diradical character for a variety of extended π‐conjugated systems, including some salient recent examples of nanographenes and polycyclic aromatic radicals, are provided based on their [4 n ]annulene peripheries. The realization of such structure–property relationships has led to a beneficial pedagogic exercise establishing design guidelines for diradicaloids. The antiaromatic fingerprint of the [4 n ]annulene peripheries upon orbital interactions due to internal covalent connectors gives insights into the diradicaloid property of a diversity of π‐conjugated molecules that have fascinated chemists recently. Antiaromaticity ; Annulene ; Aromaticity ; Diradical ; Conjugated system ; Chemistry ; Graphyne ; Computational chemistry ; Molecule ; Helicene ; Chemical physics ; Density functional theory ; Organic chemistry ; Physics ; Polymer ; Quantum mechanics Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Synthesis and characterization of novel inorganic/organometallic compounds
Authors: Hitomi Ohmagari | Nicolas Marets | Jun Kamata | Mayo Yoneyama | Takumi Miyauchi | Y. Takahashi | Yukina Yamamoto | Yuto Ogihara | Daisuke Saito | Kenta Goto | A. Ishii | Masako Kato | Miki Hasegawa
Source: Frontiers in Chemistry (article, 2022-12-07)
Field: Materials Science — Materials Chemistry

Thermosensitive visible-light-excited visible-/NIR-luminescent complexes with lanthanide sensitized by the π-electronic system through intramolecular H-bonding Visible-luminescent lanthanide (Ln<b>L</b>) complexes with a highly planar tetradentate ligand were successfully developed for a visible-light solid-state excitation system. <b>L</b> was designed by using two 2-hydroxy-3-(2-pyridinyl)-benzaldehyde molecules bridged by ethylenediamine, which was then coordinated to a series of Ln ions (Ln = Nd, Sm, Eu, Gd, Tb, Dy, and Yb). From the measurement of single-crystal X-ray analysis of Eu<b>L</b>, two phenolic O atoms and two imine N atoms in <b>L</b> were coordinated to the Eu ion, and each π-electronic system took coplanar with the edged-pyridine moiety through an intramolecular hydrogen bond. The enol group on the phenolic skeleton changed to the keto form, and the pyridine was protonated. Thus, intramolecular proton transfer occurred in <b>L</b> after the complexation. Other complexes take isostructure. The space group is <i>P</i>-1, and the <i>c</i>-axis shrinks with decreasing temperature without a phase transition in Eu<b>L</b>. The yellow color caused by the planar structure of <b>L</b> can sensitize ff emission by visible light, and the luminescence color of each complex depends on central Ln ions. Furthermore, a phosphorescence band also appeared at rt with ff emission in Ln<b>L</b>. Drastic temperature dependence of luminescence was clarified quantitatively. Intramolecular force ; Luminescence ; Lanthanide ; Chemistry ; Phosphorescence ; Photochemistry ; Excited state ; Crystallography ; Pyridine ; Hydrogen bond ; Protonation ; Ion ; Molecule ; Fluorescence ; Materials science ; Stereochemistry ; Organic chemistry Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes ; Luminescence and Fluorescent Materials
Authors: Thomas A. R. Purcell | Matthias Scheffler | Luca M. Ghiringhelli | Christian Carbogno
Source: arXiv (Cornell University) (preprint, 2022-04-27)
Field: Materials Science — Materials Chemistry

Accelerating Materials-Space Exploration for Thermal Insulators by Mapping Materials Properties via Artificial Intelligence Reliable artificial-intelligence models have the potential to accelerate the discovery of materials with optimal properties for various applications, including superconductivity, catalysis, and thermoelectricity. Advancements in this field are often hindered by the scarcity and quality of available data and the significant effort required to acquire new data. For such applications, reliable surrogate models that help guide materials space exploration using easily accessible materials properties are urgently needed. Here, we present a general, data-driven framework that provides quantitative predictions as well as qualitative rules for steering data creation for all datasets via a combination of symbolic regression and sensitivity analysis. We demonstrate the power of the framework by generating an accurate analytic model for the lattice thermal conductivity using only 75 experimentally measured values. By extracting the most influential material properties from this model, we are then able to hierarchically screen 732 materials and find 80 ultra-insulating materials. Computer science ; Field (mathematics) ; Artificial intelligence ; Mathematics Machine Learning in Materials Science ; Topic Modeling ; Catalysis and Oxidation Reactions
Authors: S. Di Stefano | Carlo Petrone | Stephan Russenschuck | Francesco Braghin
Source: Physical Review Accelerators and Beams (article, 2022-05-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Data-driven modeling of nonlinear materials in normal-conducting magnets Accurate numerical modeling of normal-conducting accelerator magnets requires a reliable characterization of the iron saturation and hysteresis as well as a precise knowledge of the magnet geometry as built. Computations of the field quality are not easily achieving the accuracy required by the accelerator operation, particularly for eddy-current effects in fast-ramping magnets. This paper proposes a (measurement) data-driven model for the nonlinear magnetization of normal-conducting magnets. The model adopts a volume integral formulation compatible with eddy-current simulations. A two-step updating procedure is applied. The first step is the fitting of material parameters directly in the magnet model. The second step is the updating of the magnetization by measurements of the integral field harmonics. The result is a full-order updated model that can be employed in static or dynamic simulations. Finally, the procedure is validated on an iron-dominated, normal-conducting magnet. Magnet ; Eddy current ; Harmonics ; Nonlinear system ; Computation ; Hysteresis ; Magnetization ; Computer science ; Physics ; Saturation (graph theory) ; Field (mathematics) ; Mechanics ; Mechanical engineering ; Magnetic field ; Computational physics ; Control theory (sociology) ; Materials science ; Voltage ; Condensed matter physics ; Engineering ; Mathematics ; Algorithm Magnetic Properties and Applications ; Electric Motor Design and Analysis ; Non-Destructive Testing Techniques
Authors: Mary K. Chaves | Ron C. Kelly | Jacqueline E. Milne | Susan Burke
Source: Pharmaceutical Development and Technology (article, 2022-05-28)
Field: Chemistry — Analytical Chemistry

Data-driven approach to mitigate quality impact of hygroscopic pharmaceutical raw materials throughout the supply chain The challenges of working with hygroscopic pharmaceutical raw materials can have a significant impact on the industry's ability to make high-quality medicines. In order to mitigate the impact to the manufacturing process or product quality it is critical to understand the hygroscopicity of the raw materials across the entire supply chain so that the proper management strategies can be implemented, from the raw material manufacturing to the use of the raw material in the drug manufacturing process. Employing suitable controls protects these materials from physical and chemical changes due to moisture uptake such as caking or hydrolysis. We have developed a fit for purpose and data-driven approach to hygroscopicity classifications of over 200 commonly used chemicals, excipients, media and resins in drug manufacturing processes. Dynamic vapor sorption data is presented with supporting thermal gravimetric analysis and X-ray powder diffraction data where pertinent. Approximately 60% of all raw materials tested were determined to be hygroscopic. Strategies for applying this data to reduce the potential impact of hygroscopic materials on the manufacturing of pharmaceuticals are discussed with examples. Supply chain ; Raw material ; Quality (philosophy) ; Process engineering ; Pharmaceutical technology ; Business ; Materials science ; Biochemical engineering ; Nanotechnology ; Chemistry ; Chromatography ; Marketing ; Engineering Spectroscopy and Chemometric Analyses ; Drug Solubulity and Delivery Systems ; Food composition and properties