jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Vicente Macián | Bernardo Tormos | Antonio García-Barberá | A. Tsolakis
Source: Chemometrics and Intelligent Laboratory Systems (article, 2020-12-02)
Field: Chemistry — Analytical Chemistry

Applying chemometric procedures for correlation the FTIR spectroscopy with the new thermometric evaluation of Total Acid Number and Total Basic Number in engine oils Fourier transform infrared spectroscopy ; Acid value ; Titration ; Process engineering ; Analytical Chemistry (journal) ; Chemometrics ; Chemistry ; Biological system ; Computer science ; Mathematics ; Chromatography ; Engineering ; Chemical engineering ; Physical chemistry Spectroscopy and Chemometric Analyses ; Water Quality Monitoring and Analysis ; Scientific Measurement and Uncertainty Evaluation
Authors: J. Liu | Lei Zhao | Yifan Guo | Haiyang Zhang | Zebang Zhang
Source: eXPRESS Polymer Letters (article, 2020-01-01)
Field: Materials Science — Polymers and Plastics

Multi-responsive shape memory polymer printed by fused deposition modeling technique With the help of three-dimensional (3D) printing technique, complicated and sophisticated structured shape memory polymers (SMPs) devices could be obtained, which have drawn tremendous attention in recent years. However, there is technical limitation for 3D photo-polymerization printing technique to prepare multi-responsive SMP devices. A major problem for this is that functional fillers added to the photo-curing resins disturb or even inhibit their photo polymerization process. Herein, we demonstrated that the fused deposition modeling (FDM) technology seems more promising for fabrication of multi-responsive SMP devices. In this research, SMP devices are printed using a new material, polycyclooctene (PCO), whose application in FDM printing is never reported in the previous work. A universal and facile method, gammaray irradiation, is used to realize the crosslinking of printed structures. The printing quality and thermo-responsive speed of SMPs can be improved by incorporation of highly thermal conductive fillers (hexagonal boron nitride, BN) to PCO; in addition, after the addition of multiwalled carbon nanotubes (MWCNTs), the 3D SMP devices obtained multi-responsive ability owing to the enhanced electrical conduction and light absorption of the composite materials. Fused deposition modeling ; Materials science ; Shape-memory polymer ; Deposition (geology) ; 3d printed ; Polymer ; Nanotechnology ; 3D printing ; Composite material ; Biomedical engineering ; Engineering Polymer composites and self-healing ; Additive Manufacturing and 3D Printing Technologies ; Photopolymerization techniques and applications
Authors: Heidi Therese Hillier | Bjørn Altermark | Ingar Leiros
Source: FEBS Journal (article, 2020-02-29)
Field: Materials Science — Materials Chemistry

The crystal structure of the tetrameric DABA‐aminotransferase EctB, a rate‐limiting enzyme in the ectoine biosynthesis pathway l-2,4-diaminobutyric acid (DABA) aminotransferases can catalyze the formation of amines at the distal ω-position of substrates, and is the intial and rate-limiting enzyme in the biosynthesis pathway of the cytoprotecting molecule (S)-2-methyl-1,4,5,6-tetrahydro-4-pyrimidine carboxylic acid (ectoine). Although there is an industrial interest in the biosynthesis of ectoine, the DABA aminotransferases remain poorly characterized. Herein, we present the crystal structure of EctB (2.45 Å), a DABA aminotransferase from Chromohalobacter salexigens DSM 3043, a well-studied organism with respect to osmoadaptation by ectoine biosynthesis. We investigate the enzyme's oligomeric state to show that EctB from C. salexigens is a tetramer of two functional dimers, and suggest conserved recognition sites for dimerization that also includes the characteristic gating loop that helps shape the active site of the neighboring monomer. Although ω-transaminases are known to have two binding pockets to accommodate for their dual substrate specificity, we herein provide the first description of two binding pockets in the active site that may account for the catalytic character of DABA aminotransferases. Furthermore, our biochemical data reveal that the EctB enzyme from C. salexigens is a thermostable, halotolerant enzyme with a broad pH tolerance which may be linked to its tetrameric state. Put together, this study creates a solid foundation for a deeper structural understanding of DABA aminotransferases and opening up for future downstream studies of EctB's catalytic character and its redesign as a better catalyst for ectoine biosynthesis. In summary, we believe that the EctB enzyme from C. salexigens can serve as a benchmark enzyme for characterization of DABA aminotransferases. DATABASE: Structural data are available in PDB database under the accession number 6RL5. Biosynthesis ; Enzyme ; Ectoine ; Biochemistry ; Tetramer ; Biology ; Lyase ; Active site ; Stereochemistry ; Amino acid ; Chemistry ; Osmoprotectant Enzyme Structure and Function ; Microbial Metabolic Engineering and Bioproduction ; Protein Structure and Dynamics
Authors: Tomasz K. Olszewski | Michał Bieniek | Krzysztof Skowerski
Source: Organic Process Research & Development (article, 2020-01-22)
Field: Chemistry — Organic Chemistry

Ruthenium-Based Complexes Bearing Quaternary Ammonium Tags as Versatile Catalysts for Olefin Metathesis: From the Discovery to Practical Applications This personal account describes the development and fine-tuning of pH-neutral quaternary-ammonium-tagged ruthenium-based complexes, their use as versatile catalysts for olefin metathesis, and the application of that transformation in the synthesis of complex molecules. Ruthenium ; Olefin metathesis ; Ammonium ; Catalysis ; Metathesis ; Olefin fiber ; Combinatorial chemistry ; Ring-opening metathesis polymerisation ; Chemistry ; Acyclic diene metathesis ; Organic chemistry ; Materials science ; Polymerization Synthetic Organic Chemistry Methods ; Organometallic Complex Synthesis and Catalysis ; Chemical Synthesis and Analysis
Authors: Gijs M. ter Huurne | Pongphak Chidchob | A.M. Long | Alexandre Martinez | Anja R. A. Palmans | Ghislaine Vantomme
Source: Chemistry - A European Journal (article, 2020-04-29)
Field: Materials Science — Biomaterials

Controlling the Length of Cooperative Supramolecular Polymers with Chain Cappers The design and the characterization of supramolecular additives to control the chain length of benzene-1,3,5-tricarboxamide (BTA) cooperative supramolecular polymers under thermodynamic equilibrium is unraveled. These additives act as chain cappers of supramolecular polymers and feature one face as reactive as the BTA discotic to interact strongly with the polymer end, whereas the other face is nonreactive and therefore impedes further polymerization. Such a design requires fine tuning of the conformational preorganization of the amides and the steric hindrance of the motif. The chain cappers studied are monotopic derivatives of BTA, modified by partial N-methylation of the amides or by positioning of a bulky cyclotriveratrylene cage on one face of the BTA unit. This study not only clarifies the interplay between structural variations and supramolecular interactions, but it also highlights the necessity to combine orthogonal characterization methods, spectroscopy and light scattering, to elucidate the structures and compositions of supramolecular systems. Chain (unit) ; Polymer ; Supramolecular polymers ; Supramolecular chemistry ; Polymer science ; Materials science ; Polymer chemistry ; Chemistry ; Crystallography ; Composite material ; Physics Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Supramolecular Chemistry and Complexes
Authors: Fiora Artusio | Albert Castellví | Anabel Sacristán | Roberto Pisano | José A. Gavira
Source: Crystal Growth & Design (article, 2020-07-08)
Field: Materials Science — Materials Chemistry

Agarose Gel as a Medium for Growing and Tailoring Protein Crystals The nucleation inducing ability of agarose gels has been exploited to study the crystallization of proteins in diffusion-dominated environments. The crystal size was successfully tuned in a wide range of gel, protein, and precipitant concentrations. The impact of the gel content on crystal size was independent of the specific protein, allowing the mathematical prediction of crystal size and pointing out the exclusivity of physical interactions between the gel and the protein. The versatility of the technique and the fine-tuning of the nucleation flux was demonstrated by crystallizing five different proteins and implementing batch and counter-diffusion crystallization. In addition, the potential of agarose gel to be used not only as a growth but also as a delivery medium for serial crystallography applications has been proven by preparing unidimensional microcrystal slurries with 0.1% (w/v) gel. Agarose ; Nucleation ; Crystallization ; Protein crystallization ; Diffusion ; Crystal (programming language) ; Materials science ; Crystal growth ; Chemical engineering ; Chemistry ; Chromatography ; Crystallography ; Organic chemistry ; Computer science Enzyme Structure and Function ; Crystallization and Solubility Studies ; Enzyme Production and Characterization
Authors: Francesca Nunzi | Giacomo Pannacci | Francesco Tarantelli | Leonardo Belpassi | David Cappelletti | Stefano Falcinelli | Fernando Pirani
Source: Molecules (review, 2020-05-20)
Field: Chemistry — Inorganic Chemistry

Leading Interaction Components in the Structure and Reactivity of Noble Gases Compounds The nature, strength, range and role of the bonds in adducts of noble gas atoms with both neutral and ionic partners have been investigated by exploiting a fine-tuned integrated phenomenological-theoretical approach. The identification of the leading interaction components in the noble gases adducts and their modeling allows the encompassing of the transitions from pure noncovalent to covalent bound aggregates and to rationalize the anomalous behavior (deviations from noncovalent type interaction) pointed out in peculiar cases. Selected adducts affected by a weak chemical bond, as those promoting the formation of the intermolecular halogen bond, are also properly rationalized. The behavior of noble gas atoms excited in their long-life metastable states, showing a strongly enhanced reactivity, has been also enclosed in the present investigation. Noble gas ; Non-covalent interactions ; Chemistry ; Reactivity (psychology) ; Chemical physics ; Covalent bond ; Intermolecular force ; Metastability ; Adduct ; Ionic bonding ; Excited state ; Noble metal ; Computational chemistry ; Molecule ; Atomic physics ; Catalysis ; Organic chemistry ; Hydrogen bond ; Ion ; Physics Inorganic Fluorides and Related Compounds ; Advanced Chemical Physics Studies ; Luminescence Properties of Advanced Materials
Authors: Atanas Kurutos | Yutaka Shindo | Yuki Hiruta | Kotaro Oka | Daniel Citterio
Source: Dyes and Pigments (article, 2020-06-11)
Field: Chemistry — Spectroscopy

Near-infrared pH responsive heptamethine cyanine platforms: Modulating the proton acceptor Piperazine ; Cyanine ; Moiety ; Chemistry ; Protonation ; Photochemistry ; Proton NMR ; Bathochromic shift ; Chromophore ; Acceptor ; Proton affinity ; Combinatorial chemistry ; Ion ; Organic chemistry ; Fluorescence Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Analytical Chemistry and Sensors
Authors: Wei Zheng | Baoyu Sun | Yuemei Li | Rui Wang | Tiyi Lei | Yanling Xu
Source: ACS Sustainable Chemistry & Engineering (article, 2020-01-27)
Field: Materials Science — Materials Chemistry

Near-Infrared Laser-Triggered Full-Color Tuning Photon Upconversion and Intense White Emission in Single Gd<sub>2</sub>O<sub>3</sub> Microparticle Full-color emission fluorescence materials are of imperious demand in information storage, graphics imaging, and anticounterfeiting fields. However, it is still a formidable challenge to develop a single material with full-color emission and high-purity white output under NIR-light excitation. Herein, we design a novel and convenient strategy to tune the upconversion luminescence color with full-color range in lanthanide ions-doped Gd2O3 microspheres via a single NIR laser sensitization. Different from the typical ion-dependent tuning of color, the bright and flexible full-color emission tuning from blue to cyan, green, yellow, pink, and red can be a controllable implementation in a single microparticle. Particularly, benefiting from the laser-sensitive color adjustment, highly intense white color emission can be simultaneously achieved in diverse doped ion concentration particles. In addition, the upconversion emission intensity has been evidently improved if using a NIR laser sensitization, leading to a significantly enhanced upconversion red luminescence signal (44-fold) at the power of 446 mW. The mechanistic investigations and dynamics analysis reveal that the unprecedented color tunability from these microcrystals is attributed to dynamic control of multienergy transfer and the multicross relaxation process. Furthermore, because of their excellent upconversion luminescence properties, Gd2O3 microparticles could be used in the anticounterfeiting application in different colors. These findings not only open a way to fabricate a single material for fine-tuning upconversion emission in a full-color gamut, but also give the possibility for construction of multicolor imaging for anticounterfeiting applications. Photon upconversion ; Materials science ; Cyan ; Laser ; Optoelectronics ; Luminescence ; Fluorescence ; Gamut ; Ytterbium ; Phosphor ; Near-infrared spectroscopy ; Optics ; Doping Luminescence Properties of Advanced Materials ; Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics
Authors: Yao Pan | Yin‐Shan Meng | Qiang Liu | Wan-Qing Gao | Chun‐Hua Liu | Tao Liu | Yuan‐Yuan Zhu
Source: Inorganic Chemistry (article, 2020-05-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Construction of SCO-Active Fe(II) Mononuclear Complexes from the Thio-pybox Ligand The development of new spin-crossover complexes provides novel promising switching materials with significant potential at the molecular level. Ter-imine-type molecules represent one of the important classes of ligands in creating SCO-active complexes. Herein we report a family of mononuclear Fe(II) SCO-active compounds constructed from a new type of ter-imine ligand named the thio-pybox ligand (2,6-bis(4,4-dimethyl-4,5-dihydrothiazol-2-yl)pyridine, <b>L</b><sup><b>1</b></sup>). Through the variation of counteranions, some cases display complete SCO and with <i>T</i><sub>1/2</sub> near ambient temperature. Among them, annealed [Fe<sup>II</sup>(L<sup>1</sup>)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub> [<b>1(ClO</b><sub><b>4</b></sub><b>)</b>] shows <i>T</i><sub>1/2↓</sub> and <i>T</i><sub>1/2↑</sub> as 319 and 349 K, respectively. The wide thermal hysteresis of Δ<i>T</i> = 30 K originated from the weak interaction between complex cations and counteranions in the crystal lattice. Impressively, its high-spin population can be increased considerably by annealing at high temperature. The metastable high-spin phase is stable in the successive magnetic measurements and would gradually relax to its initial state with high population of low-spin configuration at ambient temperature. In acetonitrile-diluted solution, <b>1(ClO</b><sub><b>4</b></sub><b>)</b> still maintains SCO with an estimated <i>T</i><sub>1/2</sub> at 240 K. Differential scanning calorimetry discloses the structural phase at around 355 K in the first heating process and the increase in the high-spin population concomitant with annealing was also corroborated by <sup>57</sup>Fe Mössbauer measurements. Additionally, the influences on SCO by counteranion and ligand structure are investigated, which show that the fine tuning of complex structures can affect the behavior of the spin state significantly. Finally, magneto-structural correlation studies were performed on the structures of <b>1(ClO</b><sub><b>4</b></sub><b>)</b> and its oxygen analogue at multiple temperatures. The analyses of some structural parameters, including terminal N···N donor separation, bite angle, patulous angle, and the root mean squared deviation indicate that the replacement of the oxygen atom with a sulfur atom can effectively improve the flexibility and release the steric strain and thus tune the SCO toward ambient temperature. Our research demonstrates the rational design of the ligand can lead to new SCO-active compounds with high performance. Chemistry ; Spin crossover ; Crystallography ; Population ; Ligand (biochemistry) ; Imine ; Acetonitrile ; Pyridine ; Spin transition ; Stereochemistry ; Organic chemistry Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal complexes synthesis and properties
Authors: Julia Pignanelli | Zhiyuan Qian | Xiaodan Gu | Mohammed Jalal Ahamed | Simon Rondeau‐Gagné
Source: New Journal of Chemistry (article, 2020-01-01)
Field: Materials Science — Polymers and Plastics

Modulating the thermomechanical properties and self-healing efficiency of siloxane-based soft polymers through metal–ligand coordination An efficient strategy to modulate the thermomechanical properties and self-healing of soft polymers has been developed by rationally selecting the metal used for supramolecular crosslinking. Chemistry ; Siloxane ; Supramolecular chemistry ; Polymer ; Self-healing ; Ligand (biochemistry) ; Supramolecular polymers ; Self-healing material ; Metal ; Polymer chemistry ; Organic chemistry ; Crystal structure ; Receptor Polymer composites and self-healing ; Carbon dioxide utilization in catalysis ; Polydiacetylene-based materials and applications
Authors: Corentin Pigot | Guillaume Noirbent | Sébastien Peralta | Sylvain Duval | Thanh‐Tuân Bui | Pierre‐Henri Aubert | Malek Nechab | Didier Gigmès | Frédéric Dumur
Source: Dyes and Pigments (article, 2020-01-07)
Field: Chemistry — Organic Chemistry

New push-pull dyes based on 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile: An amine-directed synthesis Malononitrile ; Knoevenagel condensation ; Piperidine ; Amine gas treating ; Chemistry ; Nucleophile ; Aldehyde ; Chromophore ; Electrochemistry ; Derivative (finance) ; Medicinal chemistry ; Combinatorial chemistry ; Photochemistry ; Organic chemistry ; Physical chemistry Multicomponent Synthesis of Heterocycles ; Synthesis of Organic Compounds ; Photochromic and Fluorescence Chemistry
Authors: Andrea Silva | Victor E. P. Claerbout | Tomáš Polcar | Denis Kramer | Paolo Nicolini
Source: ACS Applied Materials & Interfaces (article, 2020-09-08)
Field: Materials Science — Materials Chemistry

Exploring the Stability of Twisted van der Waals Heterostructures Recent research showed that the rotational degree of freedom in stacking 2D materials yields great changes in the electronic properties. Here, we focus on an often overlooked question: are twisted geometries stable and what defines their rotational energy landscape? Our simulations show how epitaxy theory breaks down in these systems, and we explain the observed behavior in terms of an interplay between flexural phonons and the interlayer coupling, governed by the moiré superlattice. Our argument, applied to the well-studied MoS<sub>2</sub>/graphene system, rationalizes experimental results and could serve as guidance to design twistronic devices. Materials science ; van der Waals force ; Stability (learning theory) ; Chemical physics ; Nanotechnology ; Quantum mechanics ; Molecule ; Physics 2D Materials and Applications ; Graphene research and applications ; Topological Materials and Phenomena
Authors: Abdullah Aljaafari
Source: Frontiers in Materials (article, 2020-11-18)
Field: Materials Science — Materials Chemistry

Size Dependent Photocatalytic Activity of ZnO Nanosheets for Degradation of Methyl Red In this work, ZnO nanosheets with a tunable thickness were produced by microwave-assisted hydrothermal based method. The product was well characterized by various tools such as XRD, SEM, EDX spectroscopy, TEM, and Raman spectroscopy. ZnO nanosheets were highly crystalline and possessed single phase with the wurtzite structure. The ZnO nanosheets have thickness ranging from 20 to 50 nm, as shown by the micrographs of SEM. The SAED pattern infered that the ZnO nanosheets have single crystal nature with preferential growth direction along [0001]. ZnO nanosheets with E2high mode of wurtzite structure was observed by Raman scattering spectra. The photodegradation of methyl red using ZnO nanosheets was measured under UV light irradiation. In comparison with the commercial ZnO, ZnO nanosheets showed higher efficiency in photodegradation of organic dyes. The thinner the nanosheets, the higher their performance, which can be explained based on surface area. The excellent performance of ZnO nanosheets in photodegradable organic dyes might be important in environmental treatment and photocatalysis applications. Wurtzite crystal structure ; Photodegradation ; Materials science ; Photocatalysis ; Raman spectroscopy ; Chemical engineering ; Hydrothermal circulation ; Selected area diffraction ; Nanosheet ; Zinc ; Nanotechnology ; Catalysis ; Organic chemistry ; Transmission electron microscopy ; Chemistry ; Optics ; Metallurgy ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Advanced Photocatalysis Techniques
Authors: Erno Karjalainen | Narmin Suvarli | Heikki Tenhu
Source: Polymer Chemistry (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Thermoresponsive behavior of poly[trialkyl-(4-vinylbenzyl)ammonium] based polyelectrolytes in aqueous salt solutions A systematic method to induce thermoresponsive behavior for polycations with salts from the reversed Hofmeister series is introduced. Hofmeister series ; Polyelectrolyte ; Salt (chemistry) ; Aqueous solution ; Ammonium ; Chemistry ; Lower critical solution temperature ; Salt solution ; Polymer chemistry ; Chemical engineering ; Organic chemistry ; Polymer ; Copolymer Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Molecular Sensors and Ion Detection
Authors: Haozhong Wu | Xiaojuan Song | Bing Zhang | Zhiming Wang | Tian Zhang | Anjun Qin | Ben Zhong Tang
Source: Materials Chemistry Frontiers (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Each phenyl group performs its own functions on luminescence: phenyl substituted effect in tetraphenylpyrazine Three phenyl groups of TPP derivatives affect the luminescence process in various modes. TPPs show AIE thanks to the <italic>ortho</italic> substituted groups, while <italic>meta</italic> and <italic>para</italic> groups can modulate their luminescence in different extents. Luminescence ; Group (periodic table) ; Chemistry ; Medicinal chemistry ; Materials science ; Photochemistry ; Organic chemistry ; Optoelectronics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Organic Light-Emitting Diodes Research