jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Huajian Yu | Álex Rojas | Zihao Gao | Luis Gómez‐Hortigüela | Luis A. Villaescusa | Jian Li | Jean‐Louis Paillaud | Miguel Á. Camblor
Source: Dalton Transactions (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

2-Isopropyl-1,3-dimethylimidazolium as a versatile structure-directing agent in the synthesis of zeolites An organic cation lacking specificity in its structure-directing action offers the possibility, through the screening of other structure-directing parameters, to synthesize a variety of zeolites. In this work we show that the organic structure-directing agent 2-isopropyl-1,3-dimethylimidazolium (2iPr13DMI) can produce up to seven different zeolite phases depending on water concentration, the presence of inorganic impurities, crystallization temperature and time, and germanium molar fraction. The obtained phases are very different in terms of pore system, connectivity of the zeolite structure and structural units. At the pure SiO<sub>2</sub> side, ZSM-12 and SSZ-35 dominate, with ZSM-12 being favored by the presence of potassium impurities and by less concentrated conditions. The introduction of Ge at low levels favors SSZ-35 over ZSM-12 and as the Ge fraction increases it successively affords CSV, -CLO and two distinct UOS zeolites, HPM-11 and HPM-6. These two zeolites have the same topology but distinct chemical compositions and display powder X-ray diffraction patterns that are much different from each other and from that of as-synthesized IM-16 (UOS reference material). They also show different symmetry at 96 K. Rietveld refinements of the three as-made UOS materials mentioned are provided. HPM-6 and HPM-11 are produced in distinct, non-adjacent crystallization fields. The frequent cocrystallization of the chiral STW zeolite, however, did not afford its synthesis as a pure phase. Molecular mechanics simulations of the location of the organic cation and host-guest interactions fail to explain the observed trends, but also considering the intrinsic stability of the zeolites and the effect of germanium help to rationalize the results. The study is completed by DFT calculations of the NMR chemical shifts of <sup>13</sup>C in UOS (helping to understand splittings in the spectrum) and <sup>19</sup>F in CSV (supporting the location of fluoride inside the new [4<sup>4</sup>5<sup>2</sup>], which is an incomplete double 4-ring). Isopropyl ; Chemistry ; Combinatorial chemistry ; Chemical engineering ; Organic chemistry ; Engineering Zeolite Catalysis and Synthesis ; Chemical Synthesis and Characterization ; Advanced NMR Techniques and Applications
Authors: Soumya Patra | Nimisha A. Mavlankar | Lakshminarayan Ramesan | Ashmeet Singh | Asish Pal
Source: Chemistry (article, 2023-05-10)
Field: Materials Science — Biomaterials

Tweaking of Peripheral Moieties in Catalytic Amyloid for Modulating Hydrogel Strength and Hydrolase Activity The de novo design and synthesis of peptide-based biocatalysts that can mimic the activity of natural enzymes is an exciting field with unique opportunities and challenges. In a natural enzyme, the active site is composed of an assembly of different amino acid residues, often coordinated with a metal ion. A metalloenzyme’s catalytic activity results from the dynamic and concerted interplay of various interactions among the residues and metal ions. Aiming to mimic such enzymes, simple peptide fragments, drawing structural inspiration from natural enzymes, can be utilized as a model. In our effort to mimic a metal-containing hydrolase, we designed peptide amphiphiles (PA) 1 and 2 with a terminal histidine having amide and acid functionalities, respectively, at its C-terminal, imparting differential ability to coordinate with Zn and Cu ions. The PAs demonstrate remarkable self-assembly behavior forming excellent nanofibers. Upon coordination with metal ions, depending on the coordination site the nanofibers become rigidified or weakened. Rheological studies revealed excellent mechanical properties of the hydrogels formed by the PAs and the PA–metal co-assemblies. Using such co-assemblies, we mimic hydrolase activity against a p-nitrophenyl acetate (p-NPA) substrate. Michaelis–Menten’s enzyme kinetic parameters indicated superior catalytic activity of 2 with Zn amongst all the assemblies. Artificial enzyme ; Chemistry ; Peptide ; Hydrolase ; Histidine ; Metal ions in aqueous solution ; Self-healing hydrogels ; Catalysis ; Enzyme ; Combinatorial chemistry ; Substrate (aquarium) ; Amide ; Dipeptide ; Active site ; Stereochemistry ; Metal ; Polymer chemistry ; Organic chemistry ; Biochemistry Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis ; Protein Structure and Dynamics
Authors: Janaki H. Chauhan | Bhavesh L. Dodiya | Haresh Ram
Source: ChemistrySelect (article, 2023-12-21)
Field: Chemistry — Organic Chemistry

Triazolo [1,5‐a]pyrimidines as DNA Gyrase Inhibitiors: Synthesis, Antimicrobial, Activities, and in silico ADMET with Molecular Docking Studies Abstract The study focused on developing new triazolopyrimidine derivatives as potential DNA Gyrase inhibitors and antimicrobial agents. The compounds were designed, synthesized, and evaluated for their biological activities, safety, and ADMET properties. Encouragingly, the initial results showed promising potency and acceptable ADME parameters, forming a strong basis for further drug development research. The newly synthesized compounds were verified through spectra, mass, and elemental analysis. Notably, several compounds exhibited significant activity against both Gram‐positive and Gram‐negative bacteria, with MIC values ranging from 100 μg/ml to 250 μg/ml. importantly, the compounds were found to be safe, with no reported adverse effects or toxicities. Among the tested compounds, compound 2 m stood out as an excellent DNA Gyrase inhibitor, with an IC50 value of 0.89 μM, comparable to the reference drug ciprofloxacin with an IC50 value of 0.91 μM. Molecular docking studies confirmed that the compounds′ binding mode and docking scores were similar to ciprofloxacin, validating their antibacterial activity via DNA Gyrase inhibition. The research provides valuable insights into the potential of these newly synthesized triazolopyrimidine derivatives as DNA Gyrase inhibitors and antimicrobial agents. Their promising antibacterial activity and safe profile make them potential candidates for further development as antimicrobial agents. DNA gyrase ; Antimicrobial ; Chemistry ; Ciprofloxacin ; Docking (animal) ; ADME ; In silico ; Combinatorial chemistry ; Biochemistry ; Stereochemistry ; Escherichia coli ; Antibiotics ; In vitro ; Organic chemistry ; Medicine ; Gene Synthesis and biological activity ; Synthesis and Biological Evaluation ; Cancer therapeutics and mechanisms
Authors: Csilla Enikő Czégéni | Ferenc Joó | Ágnes Kathó | Gábor Papp
Source: Catalysts (article, 2023-11-05)
Field: Chemistry — Organic Chemistry

Heterobimetallic Complexes of Bi- or Polydentate N-Heterocyclic Carbene Ligands and Their Catalytic Properties This review summarizes developments in the synthesis and catalytic applications of those heterobimetallic carbene complexes in which at least two different metals are bound to the same ligand by at least one M-C(carbene) bond each. Several new synthetic methods for such complexes yielding well-defined and thoroughly characterized compounds are presented. The new complexes were found to be catalytically active in several (most often tandem) reactions. In certain cases, the incorporation of two different metals into the same imidazole- or triazol-based NHC-carbene complex resulted in the substantially higher catalytic activity of the heterobimetallic complex compared either to its homobimetallic analogs or to mixtures of comparable mononuclear complex fragments containing the two metals independently. This is a clear demonstration of advantageous metal–metal cooperation within the catalyst. Opposite examples are also discussed, where the heterobimetallic carbene complex proved inferior in relation to its homobimetallic analogs or to mixtures of homonuclear fragments. Carbene ; Chemistry ; Catalysis ; Imidazole ; Denticity ; Ligand (biochemistry) ; Homonuclear molecule ; Combinatorial chemistry ; Metal ; Stereochemistry ; Organic chemistry ; Molecule N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions ; Synthetic Organic Chemistry Methods
Authors: Yulia Kotolevich | Evgenii Khramov | Perla Sánchez-López | Alexey Pestryakov | Yan V. Zubavichus | Joel Antúnez-García | Vitalii Petranovskii
Source: Materials (article, 2023-04-11)
Field: Materials Science — Materials Chemistry

Formation of Ag-Fe Bimetallic Nano-Species on Mordenite Depending on the Initial Ratio of Components The formation and properties of silver and iron nanoscale components in the Ag-Fe bimetallic system deposited on mordenite depend on several parameters during their preparation. Previously, it was shown that an important condition for optimizing nano-center properties in a bimetallic catalyst is to change the order of sequential deposition of components; the order "first Ag<sup>+</sup>, then Fe<sup>2+</sup>" was chosen as optimal. In this work, the influence of exact Ag/Fe atomic proportion on the system's physicochemical properties was studied. This ratio has been confirmed to affect the stoichiometry of the reduction-oxidation processes involving Ag<sup>+</sup> and Fe<sup>2+</sup>, as shown by XRD, DR UV-Vis, XPS, and XAFS data, while HRTEM, S<sub>BET</sub> and TPD-NH<sub>3</sub> show little change. However, it was found the correlation between the occurrence and amount of the Fe<sup>3+</sup> ions incorporated into the zeolite's framework and the experimentally determined catalytic activities towards the model de-NOx reaction along the series of nanomaterials elucidated in this present paper. Bimetallic strip ; High-resolution transmission electron microscopy ; Catalysis ; Mordenite ; Materials science ; X-ray photoelectron spectroscopy ; Stoichiometry ; Zeolite ; X-ray absorption fine structure ; Nanomaterials ; Chemical engineering ; Nano- ; Inorganic chemistry ; Physical chemistry ; Nanotechnology ; Chemistry ; Spectroscopy ; Transmission electron microscopy ; Organic chemistry ; Composite material Catalytic Processes in Materials Science ; Nanomaterials for catalytic reactions ; Catalysis and Oxidation Reactions
Authors: О. В. Родинков | V. N. Postnov | Valery Spivakovskyi | Ekaterina Znamenskaya | A. A. Zheludovskaya | Pavel N. Nesterenko
Source: Separations (article, 2023-07-23)
Field: Chemistry — Spectroscopy

Preconcentration of Volatile Organic Compounds on Carbon Magnetic Sorbents in the Analysis of Air by Using the Configuration Change of the Sorbent Bed during the Transition from Sorption to Thermodesorption GC-FID The new scheme of the rapid preconcentration of volatile organic substances followed by the thermodesorption and gas chromatographic determination by using a flame ionization detector is proposed for the analysis of air. The scheme implies a change in the geometry of the adsorbent layer in a column during the transition from adsorption to thermal desorption steps. The extraction of analytes is carried out in a wide tube, allowing quantitative adsorption at higher flow rates of the analyzed air passed through the magnetic sorbent held in a thin layer retained by a permanent magnet without any supporting frits. Novel magnetic adsorbents composed of magnetite or a zirconia/magnetite core and pyrocarbon shell are developed for this application. At the end of the adsorption step, the magnet moved out of the system, and the adsorbent transferred under the gravity force into a narrow tube, which provides the more efficient heating of the adsorbent and minimal blurring of the analyte zones during the subsequent thermal desorption. The proposed scheme allows a significant reduction (approximately 10 times) of the time required for the preconcentration of analytes, which is illustrated by the GC determination of alcohols (butanol-1, pentanol-1), phenol, and o-cresol in the air. Sorbent ; Adsorption ; Thermal desorption ; Sorption ; Chemistry ; Desorption ; Flame ionization detector ; Chromatography ; Analytical Chemistry (journal) ; Gas chromatography ; Magnetite ; Analyte ; Materials science ; Organic chemistry Analytical Chemistry and Chromatography ; Analytical chemistry methods development ; Advanced Chemical Sensor Technologies
Authors: Andrey V. Bukhtiyarov | Maxim A. Panafidin | Igor P. Prosvirin | Н. С. Смирнова | П. В. Марков | Г. Н. Баева | Igor S. Mashkovsky | Г. О. Брагина | З. С. Винокуров | Yan V. Zubavichus | V. I. Bukhtiyarov | A. Yu. Stakheev
Source: Crystals (article, 2023-09-08)
Field: Materials Science — Materials Chemistry

Reversible Transformations of Palladium–Indium Intermetallic Nanoparticles upon Repetitive Redox Treatments in H2/O2 The transformations of chemical states and structures occurring in the PdIn/Al2O3 catalyst upon redox treatments in different gaseous atmospheres at different temperatures are addressed by an assortment of in situ bulk- (XRD) and surface-sensitive (XPS and DRIFTS CO) techniques. Any desired state of the catalyst between two opposite extremes of highly dispersed oxide species and regularly ordered PdIn intermetallic compound could be set in fully controlled and reversible ways by selecting appropriate conditions for the reductive treatment starting from the fully oxidized state. Since mutual conversions of multi-atomic Pdn centers into single-site Pd1 centers are involved in these transformations, the methodology could be used to find an optimum balance between the activity and selectivity of the catalytic system. Intermetallic ; Indium ; Catalysis ; Redox ; Palladium ; X-ray photoelectron spectroscopy ; Oxide ; Oxidation state ; Materials science ; Selectivity ; Nanoparticle ; Chemical engineering ; Inorganic chemistry ; Chemistry ; Nanotechnology ; Metallurgy ; Organic chemistry Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Nanomaterials for catalytic reactions
Authors: Maria Gessica Ciulla | Federico Fontana | Roberto Lorenzi | Amanda Marchini | Luca Campone | Ehsan Sadeghi | А. Палеари | Sara Sattin | Fabrizio Gelain
Source: Materials Chemistry Frontiers (article, 2023-01-01)
Field: Materials Science — Biomaterials

Novel self-assembling cyclic peptides with reversible supramolecular nanostructures Supramolecular self-assembly was observed for all- l cyclic peptides, revealing the reversible transition of nanotubes/nanofibers into nanovesicles, with tunable micro and nanoarchitectures that may be potential precious tools for emerging applications. Supramolecular chemistry ; Nanotechnology ; Materials science ; Nanostructure ; Nanofiber ; Self-assembly ; Cyclic peptide ; Peptide ; Chemistry ; Organic chemistry ; Molecule Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Supramolecular Chemistry and Complexes
Authors: Bin Ma | Wei Niu | Jiantao Guo
Source: Bioorganic Chemistry (article, 2023-01-11)
Field: Chemistry — Organic Chemistry

Proximity-enhanced protein crosslinking through an alkene-tetrazine reaction Tetrazine ; Bioorthogonal chemistry ; Alkene ; Chemistry ; Moiety ; Cysteine ; Protein subunit ; Amino acid ; Combinatorial chemistry ; Stereochemistry ; Biochemistry ; Click chemistry ; Organic chemistry Click Chemistry and Applications ; Monoclonal and Polyclonal Antibodies Research ; Biochemical and Structural Characterization
Authors: Fatemeh Paborji | Mahdi Shafiee Afarani | Amir Masoud Arabi | Mehdi Ghahari
Source: International Journal of Applied Ceramic Technology (article, 2023-02-24)
Field: Chemistry — Inorganic Chemistry

Solution combustion synthesis of FeCr <sub>2</sub> O <sub>4</sub> :Zn,Al pigment powders Abstract FeCr 2 O 4 :Zn,Al pigment powders were prepared via a solution combustion synthesis method. Effects of Zn and Al dopants and less/extra Fe content on the structure, molecular bonds, and optical properties of powders were studied. Results showed that addition of dopants as well as extra/less content of Fe led to weaker combustion and consequently lower X‐ray diffraction peak intensities, lattice parameters, and differential thermal analysis peak intensities. Moreover, Fourier transform infrared analysis illustrated that the band position of Cr–O and Fe–O bonds were shifted to higher frequencies with moving away from stoichiometry. In addition, scanning electron micrographs showed that in all samples, porous spongy microstructures were formed with highly flake‐like agglomerated particles. Furthermore, there was a significant difference between the powder samples and the tiles colored with in glaze powders due to the partial dissolution of pigments in contact with the molten glaze of tiles. In comparison to the tile colored with the stoichiometric FeCr 2 O 4 pigments without dopants, the color difference (Δ E ) in the tiles colored by the iron chromite pigments doped with Zn and Al dopants and less/extra Fe content reached the high values as large as Δ E = 36.19. The solar reflectance values ( R s ) in near‐infrared region were above 50% in all samples. Near 80% R s in the tile colored by the iron chromite pigment doped with 3 mol% Zn and the yellowish brown appearance ( L * = 43.44, a * = 6.77, b * = 18.38, c * = 19.59, h = 69.79) showed that the sample was a good candidate for cool building materials such as roof tiles. Materials science ; Glaze ; Dopant ; Pigment ; Stoichiometry ; Analytical Chemistry (journal) ; Tile ; Mineralogy ; Microstructure ; Doping ; Metallurgy ; Ceramic ; Chemistry ; Composite material ; Physical chemistry Pigment Synthesis and Properties
Authors: Yuna Kim | Kazuya Kubo
Source: Pure and Applied Chemistry (article, 2023-06-01)
Field: Materials Science — Polymers and Plastics

Transition metal complexes for electrochromic and electrofluorochromic devices Abstract This minireview discusses recent advances in transition metal complexes for electrochromic (EC) and electrofluorochromic (EFC) devices. EC and EFC materials can switch their color and photoluminescence, respectively, through electrochemical redox reactions. Transition metal complexes offer promising opportunities due to their molecular design versatility for various optoelectrical properties. The review provides an overview of electrochromism and electrofluorochromism, including performance characterization methods and device fabrication techniques. It highlights EC transition metal complexes that can form thin films suitable for device applications and EFC transition metal complexes that can efficiently tune photoluminescence through electrochemical quenching mechanisms. The review also summarizes advanced functions of EC/EFC transition metal complexes, including large optical contrast, fast response, dual-switching of color and emission, and easy device fabrication, which could lead to low-cost displays. Overall, this review article presents the latest research on transition metal complexes for EC and EFC devices and their potential for practical applications. Electrochromism ; Transition metal ; Photoluminescence ; Chemistry ; Fabrication ; Nanotechnology ; Electrochromic devices ; Electrochemistry ; Characterization (materials science) ; Quenching (fluorescence) ; Redox ; Optoelectronics ; Materials science ; Electrode ; Inorganic chemistry ; Catalysis ; Physical chemistry ; Optics ; Fluorescence ; Organic chemistry Transition Metal Oxide Nanomaterials ; Conducting polymers and applications ; Polyoxometalates: Synthesis and Applications
Authors: Michele Formica | Branislav Ferko | T. R. Marsh | Timothy A. Davidson | Ken Yamazaki | Darren J. Dixon
Source: ChemRxiv (preprint, 2023-12-05)
Field: Chemistry — Inorganic Chemistry

Second Generation Catalytic Enantioselective Nucleophilic Desymmetrization at P(V): Improved Generality, Efficiency and Modularity A second generation catalytic two-phase strategy for the enantioselective synthesis of chiral at P(V) compounds is described. This protocol, consisting of a bifunctional iminophosphorane (BIMP) catalyzed nucleophilic desymmetrization of prochiral, bench stable P(V) precursors and subsequent enantiospecific substitution allows for divergent access to a wide range of C-, N-, O- and S- substituted P(V) containing compounds from a handful of enantioenriched precursors. A new catalyst/leaving group combination allowed for a far wider substrate scope and increased reaction efficiency and practicality over previously established protocols. The resulting enantioenriched intermediates could then be converted to an even greater range of distinct classes P(V) of compounds by displacement of the remaining leaving group as well as allowing for even further diversification downstream. Density functional theory (DFT) calculations were performed to pinpoint the origin of enantioselectivity for the BIMP-catalyzed desymmetrization, to rationalize how a superior catalyst/leaving group combination leads to increased generality in our second-generation catalytic system, as well as to shed light onto observed retention and inversion pathways when performing late-stage enantiospecific SN2@P reactions with Grignard reagents. Desymmetrization ; Enantioselective synthesis ; Chemistry ; Nucleophile ; Catalysis ; Bifunctional ; Combinatorial chemistry ; Leaving group ; Stereochemistry ; Organic chemistry Asymmetric Hydrogenation and Catalysis ; Asymmetric Synthesis and Catalysis ; Chemical Synthesis and Analysis
Authors: Manouchehr Jahangir
Source: International Journal of Biomedical Investigation (article, 2023-11-10)
Field: Materials Science — Biomaterials

Efficacy of Metallic Nanoparticles and Nanocarriers as an Advanced Tool for Imaging and Diagnosis: Insight into Theranostic Applications The development of nanotechnology has brought diagnosis and therapy closer together, making theranostic compounds a promising area of study. Theranostic substances can both diagnose and treat a patient's condition. For their potential use in treating a wide range of ailments, including cancer, TB, diabetes, etc., metallic nanoparticles are currently the subject of intensive research. Modern nanotechnology allows for the precise assembly of medicinal chemicals onto metallic nanoparticles, which can then be used for targeted drug delivery, illness detection, and even imaging. Problems that must be solved before metallic theranostic agents can be successfully implemented in clinical settings include their complicated design, instability, toxicity, drug release regulation, mass production, and the potential for behavioral, psychological, and metabolic side effects. This article reviews the recent progress made in using metallic nanoparticles like gold, carbon, and iron oxide nanoparticles as theranostic agents. We also provide a brief summary of the various imaging properties of metallic nanoparticles. Finally, this in-depth analysis discusses new patents associated with metallic nanoparticles as a theranostic agent. Nanocarriers ; Nanotechnology ; Nanoparticle ; Applications of nanotechnology ; Drug delivery ; Materials science ; Nanomedicine Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Nanoparticles: synthesis and applications