jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Prem Kumar Shrestha | Pawan Raj Shakya
Source: Journal of Nepal Chemical Society (article, 2020-08-06)
Field: Materials Science — Materials Chemistry

Synthesis and Structural Characterization of Some Lanthanide(III) Nitrate Complexes with a Mesogenic Schiff-Base, N,N’-di-4-(4’-heptadecyloxybenzoate) salicylidene-1,3-diaminopropane Derived from 2,4- dihydroxybenzaldehyde Complexes of La(III), Pr(III), Nd(III), Sm(III), Gd(III) and Dy(III) with the Schiff-base, N,N′-di-4-(4’-heptadecyloxybenzoate)salicylidene-1,3-diaminopropane, (abbreviated as H2L) have been synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic, electronic, infrared, 1H and 13C NMR spectral techniques. The nephelauxetic ratio (β), the bonding parameter (b1/2), Sinha’s parameter (%δ) and angular overlap parameter (η) have been calculated from the electronic spectra of Pr(III), Nd(III), Sm(III) and Dy(III) complexes. Infrared and NMR spectral data imply a bi-dentate bonding of the Schiff-base in its zwitterionic form (as LH2) to the Ln(III) ions through two phenolate oxygens, rendering the overall geometry around Ln(III) to distorted square antiprism. Polarized optical microscopy (POM) and differential scanning calorimetry (DSC) shows the liquid crystalline property of the ligand with a nematic (N) mesophase. Among the metal complexes, only that of the Gd(III) exhibits smectic B (SmB) and nematic (N) phases. Schiff base ; Lanthanide ; Crystallography ; Mesogen ; Chemistry ; Ligand (biochemistry) ; Square antiprism ; Carbon-13 NMR ; Differential scanning calorimetry ; Proton NMR ; Metal ions in aqueous solution ; Molar conductivity ; Ion ; Stereochemistry ; Organic chemistry ; Polymer Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes ; Chemical Thermodynamics and Molecular Structure
Authors: Harrison D. Root | Grégory Thiabaud | Jonathan L. Sessler
Source: Frontiers of Chemical Science and Engineering (article, 2020-01-08)
Field: Chemistry — Spectroscopy

Reduced texaphyrin: A ratiometric optical sensor for heavy metals in aqueous solution Chemistry ; Aqueous solution ; Metal ions in aqueous solution ; Metal ; Porphyrin ; Naked eye ; Redox ; Fluorescence ; Ligand (biochemistry) ; Absorption (acoustics) ; Selectivity ; Inorganic chemistry ; Qualitative inorganic analysis ; Photochemistry ; Detection limit ; Chromatography ; Organic chemistry ; Materials science Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Advanced biosensing and bioanalysis techniques
Authors: Namiq Q. Shikhaliyev | Abel M. Maharramov | Gulnar T. Suleymanova | G.V. Babаyeva | Gunay Z. Mammadova | Irada M. Shikhaliyeva | Aliyar A. Babazade | Valentine G. Nenajdenko
Source: ARKIVOC (article, 2020-12-24)
Field: Chemistry — Physical and Theoretical Chemistry

Halogen-bonding in 3-nitrobenzaldehyde-derived dichlorodiazadienes A set of 4,4-dichloro-1,2-diazabutadienes derived from 3-nitrobenzaldehyde was prepared by the copper catalyzed reaction of the corresponding hydrazones with CCl4 in the presence of TMEDA. The structure of all products was confirmed by 1 H and 13 C NMR spectra and ESI-MS. X-ray diffraction revealed ClO halogen binding in the crystal form for some dienes. Moreover, Br and Cl types of halogen bonds are observed. Azo dyes absorb in the UV-Vis region with the max located at about 234-437 nm in CH2Cl2, DMF and MeOH. Both absorption intensity and max is dependent on the solvent polarity and the electronwithdrawing/donating ability of para-substituents on the aromatic moiety of the dichlorodiazadienes. N N Cl Cl N X Halogen bond Halogen bond acceptor X = CH 3 , Cl, Br 3.075 (CH 3 ) < 3.245 (Cl) < 3.256 (Br) O O d d Chemistry ; Halogen ; Halogen bond ; Organic chemistry Crystallography and molecular interactions ; Structural and Chemical Analysis of Organic and Inorganic Compounds ; Chemical Thermodynamics and Molecular Structure
Authors: Mohamad Nor Amirul Azhar Kamis | Hamizah Mohd Zaki | Nornizar Anuar | Mohammad Noor Jalil
Source: Indonesian Journal of Chemistry (article, 2020-05-09)
Field: Chemistry — Physical and Theoretical Chemistry

Synthesis, Characterization and Morphological Study of Nicotinamide and &lt;i&gt;p&lt;/i&gt;-Coumaric Acid Cocrystal Cocrystallization is one of the potent methods used to modify the physicochemical properties of drugs. Cocrystal of nicotinamide (NIC):p-coumaric acid (COU) was synthesized by a slow evaporation method using acetonitrile. The cocrystals with different feed molar ratios (NIC:COU : 1:1, 1:2, and 2:1) were characterized using DSC, PXRD, and FTIR, which revealed the formation of different polymorphs for each feed molar ratio. A single crystal of the NIC:COU (1:1) cocrystal was analyzed using single crystal X-ray diffraction (SCD), and 1H-NMR revealed a greater cocrystal structure stability compared to the previously published cocrystal. The intermolecular hydrogen bonds, N-H···O, and O-H···O interactions played a major role in stabilizing the cocrystal structure. A molecular modeling technique was used for prediction and surface chemistry assessment of the morphology showed an elongated (along y-axis) octagonal crystal shape which was in a reasonable agreement with the experimental crystal morphology. The reduction in values of the cocrystal solubility in ethanol was supported by the DSC data and simulation of crystal facets where most the crystal facets exposed to polar functional groups. At the concentration of 31.3 µM, NIC:COU (1:1) cocrystal showed more effective DPPH scavenging with 77.06% increased activity compared to NIC at the same concentration. Cocrystal ; Chemistry ; Hydrogen bond ; Crystallography ; Nicotinamide ; Crystal (programming language) ; Acetonitrile ; Intermolecular force ; Single crystal ; p-Coumaric acid ; Fourier transform infrared spectroscopy ; Crystal structure ; Solubility ; Stereochemistry ; Nuclear chemistry ; Molecule ; Organic chemistry ; Chemical engineering ; Chromatography Crystallography and molecular interactions ; Crystallization and Solubility Studies ; Crystal structures of chemical compounds
Authors: Yamin Leprince‐Wang | Nathan Martin | Yamina Ghozlane Habba | Marie Le Pivert | Martine Capochichi‐Gnambodoe
Source: NanoWorld Journal (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

ZnO Nanostructure Based Photocatalysis for Water Purification Yamin Leprince-Wang, Nathan Martin, Yamina Ghozlane Habba, Marie Le Pivert and Martine Capochichi-Gnambodoe In recent years, semiconductor based photocatalysis has shown great potential for an application as a low-cost, environmentally friendly and sustainable water treatment technology. Its efficiency has been widely demonstrated on the removal of persistent organic compounds in water. Photocatalysis ; Nanostructure ; Materials science ; Nanotechnology ; Portable water purification ; Chemical engineering ; Environmental science ; Chemistry ; Environmental engineering ; Catalysis ; Engineering ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Copper-based nanomaterials and applications
Authors: Rosalind L. Booth | Gideon Grogan | Keith S. Wilson | Anne‐Kathrin Duhme‐Klair
Source: RSC Chemical Biology (review, 2020-01-01)
Field: Chemistry — Organic Chemistry

Artificial imine reductases: developments and future directions Biocatalytic imine reduction has been a topic of intense research by the artificial metalloenzyme community in recent years. Artificial constructs, together with natural enzymes, have been engineered to produce chiral amines with high enantioselectivity. This review examines the design of the main classes of artificial imine reductases reported thus far and summarises approaches to enhancing their catalytic performance using complementary methods. Examples of utilising these biocatalysts <i>in vivo</i> or in multi-enzyme cascades have demonstrated the potential that artIREDs can offer, however, at this time their use in biocatalysis remains limited. This review explores the current scope of artIREDs and the strategies used for catalyst improvement, and examines the potential for artIREDs in the future. Perspective (graphical) ; Imine ; Class (philosophy) ; Computer science ; Nanotechnology ; Data science ; Management science ; Artificial intelligence ; Chemistry ; Engineering ; Materials science ; Biochemistry Cyclopropane Reaction Mechanisms ; Enzyme Catalysis and Immobilization ; Asymmetric Hydrogenation and Catalysis
Authors: Celia Idelson | Leah Webster | Tobias Krämer | F. Mark Chadwick
Source: Dalton Transactions (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Asymmetric bis-PNP pincer complexes of zirconium and hafnium – a measure of hemilability Asymmetrically-bound pyrrolide-based bis-PNP pincer complexes of zirconium and hafnium have been formed. The [κ2-PNPPh][κ3-PNPPh]MCl2 species are in direct contrast to previous zirconium PNP pincer complexes. The pincer ligands are fluxional in their binding and the energy barrier for exchange has been approximated using VT-NMR spectroscopy and the result validated by DFT calculations. Hafnium ; Pincer movement ; Zirconium ; Measure (data warehouse) ; Chemistry ; Inorganic chemistry ; Organic chemistry ; Catalysis ; Computer science ; Data mining Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties ; Lanthanide and Transition Metal Complexes
Authors: Miguel Galvez
Source: Information Display (article, 2020-09-01)
Field: Materials Science — Surfaces, Coatings and Films

New Innovations in Coating Technologies for Display Glass Abstract Antiglare, antireflective, antifingerprint, and antimicrobial display coatings are constantly being improved. Here, we look at the approaches that are gaining traction amid the pandemic. Coating ; Materials science ; Computer graphics (images) ; Computer science ; Nanotechnology Optical Coatings and Gratings ; Photonic Crystals and Applications ; TiO2 Photocatalysis and Solar Cells
Authors: Teresa S. Ortner
Source: Communications Chemistry (article, 2020-10-30)
Field: Materials Science — Materials Chemistry

Precise deposition of platinum sub-nanoclusters on Cu-doped CeO2 for low temperature CO oxidation Platinum catalysts are widely employed for vehicle exhaust treatment, but their activity is poor when the catalyst is cold. Now, precise control of the interfacial structure of platinum sub-nanoclusters on copper-doped ceria delivers excellent activity at low temperatures. Nanoclusters ; Platinum ; Doping ; Deposition (geology) ; Materials science ; Nanotechnology ; Chemical engineering ; Chemistry ; Optoelectronics ; Catalysis ; Geology ; Engineering Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Copper-based nanomaterials and applications
Authors: Karin El Rifaii | H. H. Wensink | Thomas Bizien | Jean‐Christophe P. Gabriel | Laurent J. Michot | Patrick Davidson
Source: Langmuir (article, 2020-10-14)
Field: Chemistry — Organic Chemistry

Destabilization of the Nematic Phase of Clay Nanosheet Suspensions by Polymer Adsorption Complex aqueous mixtures comprised of swelling clays and hydrosoluble polymers naturally occur in soils and play a major role in pedogenesis. They are also very often used for formulating oil-well drilling fluids, paints, and personal-care products. The suspensions of some natural clays, thanks to their large nanoparticle aspect ratio, spontaneously form nematic liquid-crystalline phases where the particles align parallel to each other, which affects their flow properties. We observed that adding small amounts of hydrosoluble polymers to these clay suspensions destabilizes the nematic phase with respect to the isotropic (disordered) phase. The polymers that we used (poly(ethylene oxide) and dextran) were too small to adopt particle-bridging conformations and small-angle X-ray scattering experiments showed that the structure of the nematic phase is not altered by polymer doping. However, the adsorption isotherm shows that the macromolecules adsorb onto the clay nanosheets, effectively coating them with a polymer layer. Our extension of Onsager's theory for polymer-coated platelets properly captures the experimental phase diagram and shows how the nematic phase destabilization can be due to the polymer adsorbing more on the platelet faces than at the rim. Because the flow properties of the nematic phase are very different from those of the isotropic phase, the presence or absence of the former phase is an important factor to be determined and considered to explain the rheological behavior of these complex systems. Liquid crystal ; Polymer ; Materials science ; Phase (matter) ; Chemical engineering ; Adsorption ; Polymer adsorption ; Ethylene oxide ; Rheology ; Phase diagram ; Aqueous solution ; Chemical physics ; Polymer chemistry ; Composite material ; Organic chemistry ; Chemistry ; Copolymer Surfactants and Colloidal Systems ; Pickering emulsions and particle stabilization ; Liquid Crystal Research Advancements
Authors: Олег С. Чудин | Victor V. Verpekin | Alexandеr A. Kondrasenko | Galina V. Burmakina | D. A. Piryazev | A. D. Vasiliev | Нина И. Павленко | Dmitry V. Zimonin | Anatoly I. Rubaylo
Source: Inorganica Chimica Acta (article, 2020-01-23)
Field: Chemistry — Organic Chemistry

Chemistry of vinylidene complexes. XXV. Synthesis and reactions of binuclear µ-vinylidene RePt complexes containing phosphite ligands. Spectroscopic, structural and electrochemical study Chemistry ; Triphenylphosphine ; Ligand (biochemistry) ; Substitution reaction ; Medicinal chemistry ; Stereochemistry ; Nuclear magnetic resonance spectroscopy ; Redox ; Electrochemistry ; Catalysis ; Inorganic chemistry ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties ; Asymmetric Hydrogenation and Catalysis
Authors: Cyrielle Ibanez | Laurence Lecamp | Fabien Boust | P. Lebaudy | Fabrice Burel
Source: Journal of Photochemistry and Photobiology A Chemistry (article, 2020-07-24)
Field: Chemistry — Organic Chemistry

Elaboration of epoxy/silica composites by cationic photopolymerization: Kinetic study, optical and mechanical characterization Photopolymer ; Materials science ; Epoxy ; Composite material ; Cationic polymerization ; Fourier transform infrared spectroscopy ; Glass transition ; Composite number ; Refractive index ; Polymer chemistry ; Chemical engineering ; Polymer ; Polymerization Photopolymerization techniques and applications ; Silicone and Siloxane Chemistry ; Epoxy Resin Curing Processes
Authors: Yoram Vos | Ryan Lane | Christopher J. Peddie | Anouk H. G. Wolters | Jacob P. Hoogenboom
Source: Microscopy and Microanalysis (article, 2020-12-22)
Field: Materials Science — Surfaces, Coatings and Films

Retarding Field Integrated Fluorescence and Electron Microscope The authors present the application of a retarding field between the electron objective lens and sample in an integrated fluorescence and electron microscope. The retarding field enhances signal collection and signal strength in the electron microscope. This is beneficial for samples prepared for integrated fluorescence and electron microscopy as the amount of staining material added to enhance electron microscopy signal is typically lower compared to conventional samples in order to preserve fluorescence. We demonstrate signal enhancement through the applied retarding field for both 80-nm post-embedding immunolabeled sections and 100-nm in-resin preserved fluorescence sections. Moreover, we show that tuning the electron landing energy particularly improves imaging conditions for ultra-thin (50 nm) sections, where optimization of both retarding field and interaction volume contribute to the signal improvement. Finally, we show that our integrated retarding field setup allows landing energies down to a few electron volts with 0.3 eV dispersion, which opens new prospects for assessing electron beam induced damage by in situ quantification of the observed bleaching of the fluorescence following irradiation. Electron microscope ; Materials science ; SIGNAL (programming language) ; Fluorescence ; Environmental scanning electron microscope ; Scanning electron microscope ; Electron ; Optics ; Microscope ; Electron beam-induced deposition ; Transmission electron microscopy ; Electron beam processing ; Microscopy ; Fluorescence microscope ; Analytical Chemistry (journal) ; Scanning transmission electron microscopy ; Nanotechnology ; Chemistry ; Physics ; Computer science Electron and X-Ray Spectroscopy Techniques ; Advanced Electron Microscopy Techniques and Applications ; Integrated Circuits and Semiconductor Failure Analysis
Authors: Gabriel E. Gomez Pinheiro | Heiko Ihmels
Source: Journal of Fluorescence (article, 2020-12-19)
Field: Chemistry — Spectroscopy

Fluorimetric Detection of Zn2+, Mg2+, and Fe2+ with 3-Hydroxy-4-Pyridylisoquinoline as Fluorescent Probe The suitability of 3-hydroxy-4-pyridylisoquinoline to operate as fluorescent chemosensor for the detection of metal ions was investigated. For that purpose, the interactions of the title compound with selected metal ions were investigated by absorption and emission spectroscopy. The complexation of Zn<sup>2+</sup>, Fe<sup>2+</sup>, Mg<sup>2+</sup> with 1:1 and 2:1 stoichiometry leads to characteristic optical responses that depend significantly on the employed solvents, thus allowing for the fluorimetric identification and detection of particular metal cations in a matrix-based pattern analysis or by fluorimetric titrations. Chemistry ; Fluorescence ; Titration ; Metal ions in aqueous solution ; Stoichiometry ; Metal ; Absorption (acoustics) ; Fluorescence spectroscopy ; Analytical Chemistry (journal) ; Detection limit ; Ion ; Inorganic chemistry ; Photochemistry ; Chromatography ; Physical chemistry ; Organic chemistry Molecular Sensors and Ion Detection ; Electrochemical Analysis and Applications ; Porphyrin and Phthalocyanine Chemistry
Authors: Nataliya Karaush‐Karmazin | Artem V. Kuklin | Glib Baryshnikov | Lyudmila V. Begunovich | Hans Ågren | Boris F. Minaev
Source: New Journal of Chemistry (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Structure, stability and electronic properties of one-dimensional tetrathia- and tetraselena[8]circulene-based materials: a comparative DFT study Computations reveal how the electronic and optical properties can be controlled in nanostructures. Chemistry ; Electronic structure ; Stability (learning theory) ; Computational chemistry ; Nanotechnology ; Crystallography Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Graphene research and applications
Authors: Bence Kutus | Jun Zhu | Jian Luo | Qi‐Qiang Wang | Alexandru Lupan | Amr A. A. Attia | De‐Xian Wang | Johannes Hunger
Source: ChemPhysChem (article, 2020-07-09)
Field: Chemistry — Spectroscopy

Enhancement of Ion Pairing of Sr(II) and Ba(II) Salts by a Tritopic Ion‐Pair Receptor in Solution Tritopic ion-pair receptors can bind bivalent salts in solution; yet, these salts have a tendency to form ion-pairs even in the absence of receptors. The extent to which such receptors can enhance ion pairing has however remained elusive. Here, we study ion pairing of M<sup>2+</sup> (Ba<sup>2+</sup> , Sr<sup>2+</sup> ) and X<sup>-</sup> (I<sup>-</sup> , ClO<sub>4</sub><sup>-</sup> ) in acetonitrile with and without a dichlorooxacalix[2]arene[2]triazine-related receptor containing a pentaethylene-glycol moiety. We find marked ion association already in receptor-free solutions. When present, most of the MX<sup>+</sup> ion-pairs are bound to the receptor and the overall degree of ion association is enhanced due to coordinative, hydrogen-bonding, and anion-π interactions. The receptor shows higher selectivity for iodides but also stabilizes perchlorates, despite the latter are often considered as weakly coordinating anions. Our results show that ion-pair binding is strongly correlated to ion pairing in these solutions, thereby highlighting the importance of taking ion association in organic solvents into account. Chemistry ; Ion ; Hydrogen bond ; Receptor ; Ion-association ; Pairing ; Bivalent (engine) ; Acetonitrile ; Inorganic chemistry ; Molecule ; Crystallography ; Stereochemistry ; Organic chemistry ; Biochemistry ; Metal Molecular Sensors and Ion Detection ; Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes
Authors: Thomas J. J. Müller | Daniel Drießen | Lukas Biesen
Source: Synlett (article, 2020-05-29)
Field: Chemistry — Organic Chemistry

Sequentially Catalyzed Three-Component Masuda–Suzuki–Sonogashira Synthesis of Fluorescent 2-Alkynyl-4-(7-azaindol-3-yl)pyrimidines: Three Palladium-Catalyzed Processes in a One-Pot Fashion The Masuda–Suzuki–Sonogashira sequence efficiently unites, in a one-pot fashion, a borylation, an arylation, and an alkynylation in the sense of a sequentially Pd-catalyzed three-component reaction to give fluorescent 2-alkynyl-4-(7-azaindol-3-yl) pyrimidines in yields of 24–83% (14 examples). Time-dependent density-functional theory calculations supported the electronic structure of the longest wavelength absorption bands, revealing that this novel consecutive three-component synthesis opens an efficient access to alkynyl meriolins, a novel class of potential inducers of apoptosis. Sonogashira coupling ; Chemistry ; Borylation ; Palladium ; Catalysis ; Alkynylation ; Fluorescence ; Combinatorial chemistry ; Propargyl ; Organic chemistry ; Aryl Multicomponent Synthesis of Heterocycles ; Catalytic Cross-Coupling Reactions ; Catalytic C–H Functionalization Methods
Authors: Andreas Hänsel | Abubakar I. Adamu | Christos Markos | Anders Feilberg | Ole Bang | Martijn J. R. Heck
Source: Photonics (article, 2020-10-15)
Field: Chemistry — Spectroscopy

Integrated Ammonia Sensor Using a Telecom Photonic Integrated Circuit and a Hollow Core Fiber We present a fully integrated optical ammonia sensor, based on a photonic integrated circuit (PIC) with a tunable laser source and a hollow-core fiber (HCF) as gas interaction cell. The PIC also contains a photodetector that can be used to record the absorption signal with the same device. The sensor targets an ammonia absorption line at 1522.45 nm, which can be reached with indium phosphide-based telecom compatible PICs. A 1.65-m long HCF is connected on both ends to a single-mode fiber (SMF) with a mechanical splice that allows filling and purging of the fiber within a few minutes. We show the detection of a 5% ammonia gas concentration, as a proof of principle of our sensor and we show the potential to even detect much lower concentrations. This work paves the way towards a low-cost, integrated and portable gas sensor with potential applications in environmental gas sensing. Materials science ; Photodetector ; Optoelectronics ; Optical fiber ; Photonics ; Absorption (acoustics) ; Indium phosphide ; Core (optical fiber) ; Proof of concept ; Fiber optic sensor ; SIGNAL (programming language) ; Optics ; Computer science ; Physics ; Gallium arsenide Spectroscopy and Laser Applications ; Advanced Fiber Optic Sensors ; Gas Sensing Nanomaterials and Sensors