jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Б.В. Васильев | R. Yu. Smyslov | Demid A. Kirilenko | Alexander N. Bugrov
Source: Nanosystems Physics Chemistry Mathematics (article, 2021-08-28)
Field: Materials Science — Materials Chemistry

Synthesis and magnetic properties of cobalt ferrite nanoparticles formed under hydro and solvothermal conditions Cobalt ferrite nanoparticles were synthesized both in hydro and in solvothermal conditions from Co and Fe salts of different chemical nature (nitrates and chlorides) taken in a 1:2 cation ratio. Varying the chemical prehistory, synthesis temperature, isothermal holding time, and the reaction medium composition made it possible to obtain a set of CoxFe 3-x O 4 nanoparticles of different average diameters and isomorphic substitution degree x. The resulting nanoparticles' elemental composition, crystal structure, sizes, and magnetic properties were determined using EDX analysis, X-ray diffraction, transmission electron microscopy, and SQUID magnetometry. The temperature dependences of the coercivity, remanent magnetization, squareness on both the average diameter and the stoichiometry of nanoparticles are considered. CoxFe 3-x O 4 nanocrystals ranged from 11 to 29 nm were single magnetic domains and showed ferrimagnetic behavior at room temperature. The hardest magnetic nanoparticles with maximum squareness values in the high-temperature region were formed with x = 0.79 using solvothermal treatment of cobalt and iron nitrates at 250 C, 7 MPa for 10 hours. Cobalt ferrite ; Cobalt ; Materials science ; Nanoparticle ; Chemical engineering ; Ferrite (magnet) ; Metallurgy ; Nanotechnology ; Composite material ; Engineering Magnetic Properties and Synthesis of Ferrites ; Multiferroics and related materials ; Magneto-Optical Properties and Applications
Authors: Chad M. Bernier | Joseph S. Merola
Source: Preprints.org (preprint, 2021-04-26)
Field: Chemistry — Inorganic Chemistry

Design of Iridium N-Heterocyclic Carbene Amino Acid Catalysts for Asymmetric Transfer Hydrogenation of Ketones A series of chiral complexes of the form Ir(NHC)2(aa)(H)(X) (NHC = N-heterocyclic carbene, aa = chelated amino acid, X = halide) was synthesized by oxidative addition of -amino acids to iridium(I) bis-NHC compounds and screened for asymmetric transfer hydrogenation of ketones. Following optimization of the reaction conditions, NHC, and amino acid ligands, high enantioselectivity was achieved when employing the Ir(IMe)2(l-Pro)(H)(I) catalyst (IMe = 1,3-dimethylimidazol-2-ylidene), which asymmetrically reduces a range of acetophenone derivatives in up to 95% enantiomeric excess. Iridium ; Acetophenone ; Transfer hydrogenation ; Carbene ; Chemistry ; Catalysis ; Enantiomeric excess ; Medicinal chemistry ; Enantiomer ; Halide ; Amino acid ; Organic chemistry ; Enantioselective synthesis ; Ruthenium Asymmetric Hydrogenation and Catalysis ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthetic Organic Chemistry Methods
Authors: G. Albrecht | Harald Locke | Pascal Schweitzer | Jonathan Becker | Limei Chen | Peter R. Schreiner | Derck Schlettwein
Source: Materials Advances (article, 2021-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

New π-stacking motifs for molecular semiconducting materials: bis(bis(8-quinolinyl)amide)metal(<scp>ii</scp>) complexes of Cr, Mn, Fe, and Zn Metal–organic complexes with a pair of orthogonal π-systems lead to a new stacking motif in solid state and open the way to a new branch in the family of molecular semiconductors. Stacking ; Amide ; Solid-state ; Metal ; Crystallography ; Materials science ; Structural motif ; Semiconductor ; Organic semiconductor ; Chemistry ; Stereochemistry ; Organic chemistry ; Physical chemistry ; Optoelectronics ; Metallurgy Organic and Molecular Conductors Research ; Organic Electronics and Photovoltaics
Authors: Shao‐Chi Lee | Che-Ming Hsu | Hsin Kao | Liyun Li | Zong‐Nan Tsai | Yong‐Ting Tsao | Yu‐Ling Hsu | Shinje Miñoza | Cheng‐chau Chiu | Hsuan‐Hung Liao
Source: ChemRxiv (preprint, 2021-08-11)
Field: Chemistry — Organic Chemistry

Studies on the Synthesis of Perfluoroaryl Sulfides and their Application in Desulfurative Nickel-Catalyzed Reductive Cross-Coupling The C−S activation and sulfur removal from native thiols is challenging and limits the application of thiols as typical feedstock materials in organic synthesis despite their natural abundance. Herein, we describe a simple procedure to introduce a per-/polyfluoroaryl moiety, which serves as a redox-active scaffold, into alkyl/aryl thiols using nucleophilic aromatic substitution (SNAr) chemistry to activate the C−S bond. The per-/polyfluoroaryl group acts as an electron acceptor in single electron transfer events to generate radical intermediates through cleavage of the C−S bond of mercaptans and utilize them in nickel-catalyzed reductive cross-coupling reactions. In addition, using computational methods, we shed light on the mechanism of this class of SNAr reaction and show that the preference for a concerted or stepwise mechanistic pathway can be easily rationalized through a Marcus-type argument, as well as consideration of the relative stability of the potential energy surfaces. Nucleophilic aromatic substitution ; Chemistry ; Aryl ; Moiety ; Nucleophile ; Reductive elimination ; Combinatorial chemistry ; Leaving group ; Bond cleavage ; Coupling reaction ; Catalysis ; Electrophilic aromatic substitution ; Alkyl ; Nucleophilic substitution ; Organic chemistry Sulfur-Based Synthesis Techniques ; Radical Photochemical Reactions ; Catalytic C–H Functionalization Methods
Authors: Jasper N. Immink | J. J. Erik Maris | Ronja F. Capellmann | Stefan U. Egelhaaf | Peter Schurtenberger | Joakim Stenhammar
Source: Soft Matter (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

ArGSLab: a tool for analyzing experimental or simulated particle networks Microscopy and particle-based simulations are both powerful techniques to study aggregated particulate matter such as colloidal gels. The data provided by these techniques often contains information on a wide array of length scales, but structural analysis methods typically focus on the local particle arrangement, even though the data also contains information about the particle network on the mesoscopic length scale. In this paper, we present a MATLAB software package for quantifying mesoscopic network structures in colloidal samples. ArGSLab (Arrested and Gelated Structures Laboratory) extracts a network backbone from the input data, which is in turn transformed into a set of nodes and links for graph theory-based analysis. The routines can process both image stacks from microscopy as well as explicit coordinate data, and thus allows quantitative comparison between simulations and experiments. ArGSLab furthermore enables the accurate analysis of microscopy data where, <i>e.g.</i>, an extended point spread function prohibits the resolution of individual particles. We demonstrate the resulting output for example datasets from both microscopy and simulation of colloidal gels, in order to showcase the capability of ArGSLab to quantitatively analyze data from various sources. The freely available software package can be used either with a provided graphical user interface or directly as a MATLAB script. Mesoscopic physics ; MATLAB ; Software ; Graphical user interface ; Focus (optics) ; Microscopy ; Process (computing) ; Resolution (logic) ; Graph Pickering emulsions and particle stabilization ; Advanced Fluorescence Microscopy Techniques ; Material Dynamics and Properties
Authors: Temitayo O. Aiyelabola
Source: Advances in Biological Chemistry (article, 2021-01-01)
Field: Chemistry — Inorganic Chemistry

Syntheses, Characterization and Biological Activity of Novel Thiazoylazo Dye and Its Coordination Compounds The present work describes the synthesis of a novel heterocyclic azo dye by general diazonization of 2-amino-4,5-dimethylthiazole followed by the diazo- coupling of the resulting diazonium ion with 5-methyl-2-(propan-2-yl)phenol to obtain ligand L. This was characterized using Fourier-transformed infrared and electronic spectrophotometry. Ligand L was further coordinated with five metal ions, M:L, 1:2 [M = Cu(II), Mn(II), Zn(II), Ni(II) and Co(II)]. The coordination compounds obtained were characterized by electronic, IR spectrophotometry, magnetic susceptibility and percentage metal analyses. The results obtained suggested that a thiazoylazo dye was obtained as ligand L. It was proposed that two molecules of the solvent coordinated to the metal ion in addition with the ligands to give an octahedral geometry for copper(II), manganese(II) and nickel(II) complexes. On the other hand, square planar geometry was suggested for zinc(II) and cobalt(II) complexes. The anti-infla- mmatory activity of the ligand and coordination compounds was evaluated using four in vitro-based assays viz: xanthine oxidase and lipoxygenase inhibition assay, membrane stability and protein denaturation assay. The synthesized compounds generally exhibited good anti-inflammatory activity in all the assays carried out. However, the reference standards, in this instance, were more effective in the case of xanthine oxidase, lipoxygenase and protein denaturation inhibitory assays. For the membrane stability study, the coordination compounds and ligand L elicited more potent anti-inflammatory activity than the standard drug. Chemistry ; Ligand (biochemistry) ; Octahedral molecular geometry ; Metal ions in aqueous solution ; Coordination complex ; Xanthine oxidase ; Zinc ; Metal ; Cobalt ; Nuclear chemistry ; Inorganic chemistry ; Stereochemistry ; Organic chemistry ; Enzyme ; Biochemistry Vanadium and Halogenation Chemistry ; Metal complexes synthesis and properties ; Synthesis and biological activity
Authors: Thomas Bätz | Marcel Enke | Stefan Zechel | Martin D. Hager | Ulrich S. Schubert
Source: Macromolecular Chemistry and Physics (article, 2021-09-16)
Field: Chemistry — Spectroscopy

Selective Metal‐Complexation on Polymeric Templates and Their Investigation via Isothermal Titration Calorimetry Abstract Selective complexation of metal ions represents a powerful tool for the development of versatile supramolecular architectures. While research in the field of molecular devices and machinery is sophisticated, the selective formation of metal complexes is not prevalent in polymer chemistry. Thus, the implementation of orthogonal binding concepts into a polymeric matrix is presented. In this context, an end‐functionalized poly( N ‐isopropylacrylamide) (PNIPAm) carrying zinc‐porphyrin (ZnTPP) as well as a terpyridine (tpy) ligand side by side is utilized. With these binding sites, the polymer can simultaneously interact with a pyridine moiety via a ZnTPP interaction and a terpyridine unit by the formation of a bis‐terpyridine complex. The complexation behavior of this polymer and different model compounds is intensively investigated by isothermal titration calorimetry. The obtained results indicate that the reported orthogonality of these two systems is successfully transferred into a functional polymeric architecture. Terpyridine ; Isothermal titration calorimetry ; Supramolecular chemistry ; Chemistry ; Polymer chemistry ; Moiety ; Polymer ; Titration ; Context (archaeology) ; Metal ; Combinatorial chemistry ; Molecule ; Inorganic chemistry ; Organic chemistry ; Physical chemistry Molecular Sensors and Ion Detection ; Supramolecular Chemistry and Complexes ; Analytical Chemistry and Chromatography
Authors: Torben Schlebrowski | R. Ouali | Barbara Hahn | Stefan Wehner | Christian B. Fischer
Source: Polymers (article, 2021-01-06)
Field: Materials Science — Materials Chemistry

Comparing the Influence of Residual Stress on Composite Materials Made of Polyhydroxybutyrate (PHB) and Amorphous Hydrogenated Carbon (a-C:H) Layers: Differences Caused by Single Side and Full Substrate Film Attachment during Plasma Coating Polyhydroxybutyrate (PHB) is a bio-based, biodegradable and commercially used polymer, which in its native form is unfortunately not generally applicable. A widely used technique to adapt polymers to a wider range of applications is the surface modification with amorphous hydrogenated carbon (a-C:H) layers, realized by plasma-enhanced chemical vapor deposition (PE-CVD). However, this process creates intrinsic stress in the layer-polymer system which can even lead to full layer failure. The aim of this study was to investigate how the carbon layer is affected when the basic polymer film to be coated can follow the stress and bend (single side attachment) and when it cannot do so because it is firmly clamped (full attachment). For both attachment methods, the a-C:H layers were simultaneously deposited on PHB samples. Ex-situ characterization was performed using a scanning electron microscope (SEM) for surface morphology and contact angle (CA) measurements for wettability. In addition, the stress prevailing in the layer was calculated using the Stoney equation. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) measurements were used to investigate the chemical composition of the coating surface. Materials science ; Contact angle ; Polyhydroxybutyrate ; Polymer ; Wetting ; Amorphous solid ; Layer (electronics) ; Composite material ; Coating ; Scanning electron microscope ; Chemical vapor deposition ; Substrate (aquarium) ; Carbon fibers ; Chemical engineering ; Attenuated total reflection ; Fourier transform infrared spectroscopy ; Amorphous carbon ; Surface modification ; Composite number ; Nanotechnology ; Organic chemistry ; Chemistry Diamond and Carbon-based Materials Research ; Surface Modification and Superhydrophobicity ; Tribology and Wear Analysis
Authors: Eva Tejada | Janis Vella Szijj | MIRIANA CACHIA | PAULINE FALZON | Lilian M. Azzopardi | Anthony Serracino‐Inglott
Source: Asian Journal of Pharmaceutical and Clinical Research (article, 2021-04-07)
Field: Chemistry — Spectroscopy

EFFECTS OF PH AND AMOUNT OF ACETONITRILE ON THE SEPARATION OF CANNABINOIDS Objective: During reversed-phase high-performance liquid chromatography (HPLC) analyses, optimization of separation can be achieved by selecting appropriate chromatographic conditions. The retention time, peak shape, and peak size of chromatographic peaks are dependent on amount of organic modifier in the mobile phase and buffer pH. The aim of this study was to investigate the effects of varying pH, acetonitrile composition and flow rate of the mobile phase, and temperature of the stationary phase and wavelength in the development of a method to separate Δ9 tetrahydrocannabinol, cannabidiol, and cannabinol. Methods: Mobile phases with different buffer pHs and acetonitrile composition were used with ultraviolet (UV) detection wavelength of 220 nm and 228 nm. The AUPs and retention times were observed using different mobile phase flow rates and stationary phase temperatures. Results: The best results were obtained when using a mobile phase composition of 20% phosphate buffer pH 2.5 or pH 3 and 80% acetonitrile v/v at a flow rate of 2 mL/min at 220 nm. Conclusion: This rapid and easy-to-use HPLC method describes the effect of changing important chromatographic parameters on separation and retention time of cannabinoids and can be effectively applied for high throughput analysis. Acetonitrile ; Chromatography ; Cannabinol ; Chemistry ; High-performance liquid chromatography ; Cannabidiol ; Volumetric flow rate ; Phase (matter) ; Chromatographic separation ; Analytical Chemistry (journal) ; Cannabinoid ; Organic chemistry ; Cannabis Analytical Chemistry and Chromatography ; Biochemical effects in animals ; Metabolomics and Mass Spectrometry Studies
Authors: Pankaj Kapruwan | Josep Ferré‐Borrull | Lluı́s F. Marsal
Source: Sensors (article, 2021-11-24)
Field: Materials Science — Materials Chemistry

Real-Time Monitoring of Doxorubicin Release from Hybrid Nanoporous Anodic Alumina Structures This work demonstrates an advanced approach to fabricate Hybrid nanoporous anodic alumina gradient-index filters (Hy-NAA-GIFs) through a heterogeneous anodization process combining sinusoidal current-density anodization and constant potential anodization. As a result, the hybrid structure obtained reveals a single photonic stopband (PSB), which falls within the absorption region of the drug molecule and the intensity of the spectrum that are far from such absorption range. The prepared structures were loaded with the doxorubicin (DOX) drug through the drop-casting method, which allows for evaluating the maximum reflectance of the relative height of the PSB with the average reflectance of the spectrum intensity. Thereafter, this property has been applied in a flow cell setup connected to a reflectance spectrophotometer where different drug-loaded samples were placed to study the behavior and kinetics of the drug release in real-time by varying two parameters, i.e., different pore length and flow rates. As such, obtained results were analyzed with a model that includes a sum of two inverted exponential decay functions with two different characteristic time releases. Overall, this study opens up several possibilities for the Hy-NAA-GIFs to study the drug kinetics from nanoporous structures. Nanoporous ; Anodizing ; Materials science ; Stopband ; Anode ; Porosity ; Absorption (acoustics) ; Analytical Chemistry (journal) ; Chemical engineering ; Electrode ; Nanotechnology ; Optics ; Composite material ; Optoelectronics ; Chemistry ; Aluminium ; Chromatography Anodic Oxide Films and Nanostructures ; Silicon Nanostructures and Photoluminescence ; Semiconductor materials and devices
Authors: Joeri Smits | Rajendra P. Giri | Chen Shen | Diogo Mendonça | Bridget M. Murphy | Patrick Huber | Kurosch Rezwan | Michael Maas
Source: Journal of Colloid and Interface Science (article, 2021-12-23)
Field: Materials Science — Materials Chemistry

Assessment of nanoparticle immersion depth at liquid interfaces from chemically equivalent macroscopic surfaces Wetting ; Materials science ; Electrokinetic phenomena ; Contact angle ; X-ray reflectivity ; Nanoparticle ; Surface finish ; Surface roughness ; Sessile drop technique ; Chemical engineering ; Adsorption ; Nanotechnology ; Composite material ; Analytical Chemistry (journal) ; Thin film ; Chemistry ; Chromatography ; Organic chemistry Pickering emulsions and particle stabilization ; Surfactants and Colloidal Systems ; Minerals Flotation and Separation Techniques
Authors: Lei Ye | Biao Xing | Jichang Liu | Xinglong Qin | Wenxin Yu | Jinquan Xie | Lixin Hou | Hangzhou Wang | Ye Ji | Diannan Lu
Source:  (preprint, 2021-02-17)
Field: Chemistry — Analytical Chemistry

Molecular-level reaction network in delayed coking process based on structure-oriented lumping Based on the structure-oriented lumping method, a molecular-level reaction kinetic model of the delayed coking process, which adopted 24 structural increments to construct the feed molecular matrix containing 2,944 molecules, was established with a reaction network containing 74,581 reactions using MATLAB. The reliability of the model was verified by experimental results. According to the discriminant rules of structural increments, 173 structural vectors in gasoline and 1,132 structural vectors in diesel were classified into different group compositions, respectively. The model could track the reaction path of any specific molecule in the complex thermal cracking reaction network. The influences of operation conditions such as recycle ratio on the product distribution could be discovered through the calculation of the molecular-level model, which is helpful for the process optimization and precise regulation of product composition for the delayed coking plants. Process (computing) ; Gasoline ; Biological system ; Reliability (semiconductor) ; Molecule ; MATLAB ; Cracking ; Diesel fuel ; Chemistry ; Path (computing) ; Process engineering ; Computer science ; Materials science ; Chemical engineering ; Thermodynamics ; Engineering ; Physical chemistry ; Organic chemistry ; Physics ; Biology Petroleum Processing and Analysis ; Heat transfer and supercritical fluids ; Thermochemical Biomass Conversion Processes
Authors: Laurie Peverini | Kate Dunning | Francisco Andrés Peralta | Thomas Grütter
Source: Current Opinion in Pharmacology (review, 2021-12-26)
Field: Materials Science — Materials Chemistry

Photo-isomerizable tweezers to probe ionotropic receptor mechanisms Ionotropic effect ; Ion channel ; Molecular tweezers ; Gating ; Optical tweezers ; Biophysics ; Ligand (biochemistry) ; Ligand-gated ion channel ; Nanotechnology ; Chemistry ; Biology ; Computational biology ; Receptor ; Physics ; Biochemistry ; Materials science ; Molecule ; Optics Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Receptor Mechanisms and Signaling
Authors: Indra Saptiama | Fernanto Rindiyantono | Arni Aries | Yusuf Valentino Kaneti | Muhammad Iqbal
Source: Atom Indonesia (article, 2021-04-16)
Field: Materials Science — Materials Chemistry

Synthesis and Characterization of Ordered and Disordered Mesoporous Alumina as High-Performance Molybdenum-99 Adsorbents Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Molybdenum-99 ( 99 Mo) is the parent radioisotope of technetium-99m ( 99m Tc) , an essential medical radioisotope for diagnostic agents in nuclear medicine. In 99 Mo/ 99m Tc generator, a chromatography column system with 99 Mo adsorbent as a filler is usually used to produce 99m Tc in hospitals. However, it is still challenging to find high-performance adsorbents for Mo adsorption . We have synthesized both ordered and disordered mesoporous alumina and compared their performance as 99 Mo adsorbent s . These materials were prepared via a soft-templated method using a triblock copolymer as the template , followed by air calcin ation at 400 ° C. T he amount of nitric acid (HNO 3 ) and the drying time were adjusted systematically to synthesize the ordered mesoporous alumina. The obtained ordered and disordered mesoporous alumina were characterized by low-and wide-angle X -ray diffractions (XRD) , nitrogen adsorption-desorption, ther mo gravimetric analysis (TGA), scanning electron microscop y (SEM), and transmission electron microscop y (TEM). The 99 Mo adsorption capacit ies of these materials were evaluated by using the batch method. The experimental results show that the ordered mesoporous alumina has a higher 99 Mo adsorption capacity of 72.06 mg (Mo) g -1 than the disordered mesoporous alumina ( 50.12 mg (Mo) g -1 ) . The results indicate the excellent potential of o rdered mesoporous alumina as an adsorbent for the 99 Mo/ 99m Tc generator column . Mesoporous material ; Molybdenum ; Characterization (materials science) ; Materials science ; Adsorption ; Chemical engineering ; Nanotechnology ; Chemistry ; Catalysis ; Metallurgy ; Organic chemistry Mesoporous Materials and Catalysis ; Zeolite Catalysis and Synthesis ; Catalytic Processes in Materials Science