jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tsvetelina Batsalova | A. Yu. Vasil’kov | Dzhemal Moten | Anastasiia Voronova | Ivanka Teneva | А. В. Наумкин | Balik Dzhambazov
Source: Applied Sciences (article, 2023-12-01)
Field: Materials Science — Materials Chemistry

Bimetallic Gold–Iron Oxide Nanoparticles as Carriers of Methotrexate: Perspective Tools for Biomedical Applications Bimetallic nanoparticles (BMNPs) combine unique and synergistic properties of two metals, allowing new specific applications. In this study, bimetallic AuFe nanoparticles and their conjugates with methotrexate (MTX) were obtained with an environmentally safe method of metal-vapor synthesis. The composition and electronic structure of the particles were investigated with X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) spectrum and X-ray absorption spectroscopy (XANES and EXAFS). The effects of BMNP-MTX conjugates on human primary cells and tumor cell lines were evaluated with neutral red uptake and MTT in vitro cytotoxicity assays. Bright-field microscopy analyses of tumor spheroid size and evaluations of tumor spheroid vitality based on SFDA AM staining were carried out. In vitro assays for an antibacterial activity evaluation of the generated samples were performed. The influence of BMNP-MTX on cytokine production with normal leukocytes was assessed using ELISA. X-ray analyses of the samples demonstrated that gold was in the ground state Au0 as well as Au+ and Au3+ states are present in small quantities, whereas iron existed as a mixture of non-histometric oxides with states close to Fe2+ and Fe3+. The modification of the AuFe system with MTX is accompanied by a threefold increase in the relative proportion of the Au+ state. BMNP-MTX conjugates demonstrated significant antitumor activity compared to the drug alone, which proves the ability of the generated nanoconjugates to improve the effectiveness of MTX therapy. This was confirmed by a marked reduction in the size and vitality of AuFe-MTX-treated 3D tumor spheroids. In addition to their selective antitumor activity, AuFe-MTX exhibited moderate antibacterial activity and induced sample-specific cytokine production with normal human leukocytes—which points to an immunostimulatory potential. The present findings indicate important and diverse biological properties of BMNP-MTX conjugates and thus highlight perspectives for their biomedical applications and new immune-specific abilities. Bimetallic strip ; Nanoparticle ; Nuclear chemistry ; Chemistry ; X-ray photoelectron spectroscopy ; Cytotoxicity ; Absorption spectroscopy ; XANES ; Materials science ; In vitro ; Nanotechnology ; Spectroscopy ; Metal ; Chemical engineering ; Biochemistry ; Organic chemistry Nanoparticles: synthesis and applications ; Nanoparticle-Based Drug Delivery ; Graphene and Nanomaterials Applications
Authors: Alberto F. Garrido‐Castro | Yu̅ta Hioki | Yoshifumi Kusumoto | Kyohei Hayashi | Jeremy Griffin | Kaid C. Harper | Yu Kawamata | Phil S. Baran
Source: ChemRxiv (preprint, 2023-05-25)
Field: Chemistry — Organic Chemistry

Scalable Electrochemical Decarboxylative Olefination Driven by Alternating Polarity A mild, scalable (kg) metal-free electrochemical decarboxylation of alkyl carboxylic acids to olefins is disclosed. Numerous applications are presented wherein this transformation can simplify alkene synthesis and provide alternative synthetic access to valuable olefins from simple carboxylic acid feedstocks. This robust method relies on alternating polarity to maintain the quality of the electrode surface and local pH, providing a deeper understanding of the Hofer-Moest process with unprecedented chemoselectivity. Decarboxylation ; Chemoselectivity ; Polarity (international relations) ; Alkene ; Scalability ; Electrochemistry ; Carboxylic acid ; Alkyl ; Combinatorial chemistry ; Chemistry ; Computer science ; Organic chemistry ; Electrode ; Materials science ; Catalysis Radical Photochemical Reactions ; CO2 Reduction Techniques and Catalysts ; Electrochemical Analysis and Applications
Authors: Lucie Desmurs | Claudia Cammarano | Olinda Gimello | Anne Galarneau | Vasile Hulea
Source: Materials (article, 2023-10-26)
Field: Chemistry — Inorganic Chemistry

Influence of the Mesoporosity of Hierarchical ZSM-5 in Toluene Alkylation by Methanol Among the different strategies to design highly shape-selective ZSM-5 to obtain para-xylene through toluene alkylation with methanol, the introduction of mesopores to increase reactant and product diffusion has been proposed but barely studied. In this study, we prepared mesoporous ZSM-5 catalysts, named ZSM5-MT(x), from commercial ZSM-5 (Si/Al = 15), using a two-step micelle-templating procedure with octadecyltrimethylammonium bromide as a surfactant in basic medium (x = NaOH/Si). These materials were used as catalysts for the alkylation of toluene by methanol at a low contact time to avoid thermodynamic equilibrium of the xylene isomers. Compared to the parent ZSM-5, the mesoporous ZSM5-MT(x) catalysts did not improve the para-xylene selectivity, revealing that the strategy of increasing diffusion in the catalyst is not a good strategy to follow. However, ZSM5-MT(0.5) showed less deactivation on stream than the parent ZSM-5. Therefore, introducing mesopores to ZSM-5 could be interesting to explore, combined with another strategy of shape selectivity, such as the passivation of the external surface acidity. Mesoporous material ; Alkylation ; Toluene ; ZSM-5 ; Catalysis ; Methanol ; Selectivity ; Zeolite ; Xylene ; Bromide ; Chemical engineering ; Chemistry ; Materials science ; Diffusion ; Inorganic chemistry ; Organic chemistry ; Thermodynamics Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Catalytic Processes in Materials Science
Authors: Saee Gharpure | Rachana Yadwade | Shuana Mehmood | Balaprasad Ankamwar
Source: Physica Scripta (article, 2023-08-24)
Field: Materials Science — Materials Chemistry

<i>Prunus dulcis</i>-mediated zinc oxide nanoparticles: synthesis, characterization, and an evaluation of their biocidal properties Abstract Use of plant extracts for synthesizing zinc oxide (ZnO) nanoparticles is gaining importance due to their easy, eco-friendly, cost effective and non-toxic nature. In this study, an economical biosynthetic approach of ZnO formation was delineated where aqueous extract of Prunus dulcis (almond) leaves has been used as reducing/capping agent followed by their characterization studies. The present study has successfully synthesized pure, highly crystalline in nature, predominantly spherical ZnO nanoparticles within the size range 71–214 nm for nanocystallites and 526 nm-2.37 μ m for aggregated flower-shaped ZnO nanoparticles. Microbicidal properties of uncalcined and calcined ZnO nanoparticles were evaluated using test microbes (bacteria: E. coli , S. aureus , P. aeruginosa , B. subtilis ; fungi Penicillium spp. , F. oxysporum , A. flavus , R. solani ). Lack of microbicidal potential was observed against all four bacteria and fungi. When tested for toxicity against HCT-116 carcinoma cells, these nanoparticles displayed non-toxic nature. This biocompatibility is influenced by physico-chemical properties of ZnO nanoparticles as well as biological properties of living cells. Thus, these ZnO nanoparticles can serve as an innocuous machinery in disease therapeutics due to the presence of their non-microbicidal and non-antineoplastic activities. Zinc ; Nanoparticle ; Biocompatibility ; Nuclear chemistry ; Nanomaterials ; Materials science ; Bacteria ; Aqueous solution ; Nanotechnology ; Chemistry ; Organic chemistry ; Biology Nanoparticles: synthesis and applications ; Geochemistry and Elemental Analysis
Authors: Mathias Krämer | Bar Favelukis | Ayman A. El‐Zoka | Maxim Sokol | Brian A. Rosen | Noam Eliaz | Se‐Ho Kim | Baptiste Gault
Source: arXiv (Cornell University) (preprint, 2023-05-31)
Field: Materials Science — Materials Chemistry

Near-Atomic Scale Perspective on the Oxidation of Ti$_3$C$_2$T$_x$ MXenes: Insights from Atom Probe Tomography MXenes are a family of 2D transition metal carbides and nitrides with remarkable properties and great potential for energy storage and catalysis applications. However, their oxidation behavior is not yet fully understood, and there are still open questions regarding the spatial distribution and precise quantification of surface terminations, intercalated ions, and possible uncontrolled impurities incorporated during synthesis and processing. Here, atom probe tomography analysis of as-synthesized Ti$_3$C$_2$T$_x$ MXenes reveals the presence of alkali (Li, Na) and halogen (Cl, F) elements as well as unetched Al. Following oxidation of the colloidal solution of MXenes, it is observed that the alkalies enriched in TiO$_2$ nanowires. Although these elements are tolerated through the incorporation by wet chemical synthesis, they are often overlooked when the activity of these materials is considered, particularly during catalytic testing. This work demonstrates how the capability of atom probe tomography to image these elements in 3D at the near-atomic scale can help to better understand the activity and degradation of MXenes, in order to guide their synthesis for superior functional properties. MXenes ; Atom probe ; Nitride ; Materials science ; Catalysis ; Atomic units ; Atom (system on chip) ; Nanotechnology ; Chemical physics ; Impurity ; Alkali metal ; Halogen ; Chemical engineering ; Inorganic chemistry ; Chemistry ; Layer (electronics) ; Physics ; Computer science ; Organic chemistry MXene and MAX Phase Materials ; Metal and Thin Film Mechanics ; Advanced materials and composites
Authors: Zachary H. Davis | Emma A. L. Borthwick | Russell E. Morris | Sharon E. Ashbrook
Source: Physical Chemistry Chemical Physics (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Computational NMR investigation of mixed-metal (Al,Sc)-MIL-53 and its phase transitions Compositionally complex metal-organic frameworks (MOFs) have properties that depend on local structure that is often difficult to characterise. In this paper a density functional theory (DFT) computational study of mixed-metal (Al,Sc)-MIL-53, a flexible MOF with several different forms, was used to calculate the relative energetics of these forms and to predict NMR parameters that can be used to evaluate whether solid-state NMR spectroscopy can be used to differentiate, identify and characterise the forms adopted by mixed-metal MOFs of different composition. The NMR parameters can also be correlated with structural features in the different forms, giving fundamental insight into the nature and origin of the interactions that affect nuclear spins. Given the complexity of advanced NMR experiments required, and the potential need for expensive and difficult isotopic enrichment, the computational work is invaluable in predicting which experiments and approaches are likely to give the most information on the disorder, local structure and pore forms of these mixed-metal MOFs. Nuclear magnetic resonance spectroscopy ; Phase (matter) ; Metal ; Phase transition ; Materials science ; Transition metal ; Chemistry ; Chemical physics ; Crystallography ; Physical chemistry ; Computational chemistry ; Thermodynamics ; Stereochemistry ; Physics ; Organic chemistry ; Metallurgy Metal-Organic Frameworks: Synthesis and Applications ; Inorganic Fluorides and Related Compounds ; Advanced NMR Techniques and Applications
Authors: Chu Wang | Xiao Liu | Qian Wang | Wei‐Hai Fang | Xuebo Chen
Source: JACS Au (article, 2023-12-14)
Field: Chemistry — Organic Chemistry

Unveiling Mechanistic Insights and Photocatalytic Advancements in Intramolecular Photo-(3 + 2)-Cycloaddition: A Comparative Assessment of Two Paradigmatic Single-Electron-Transfer Models The synthesis of 1-aminonorbornane (1-aminoNB), a potential aniline bioisostere, through photochemistry or photoredox catalysis signifies a remarkable breakthrough with implications in organic chemistry, pharmaceutical chemistry, and sustainable chemistry. However, an understanding of the underlying mechanisms involved in these reactions remains limited and ambiguous. Herein, we employ high-precision CASPT2//CASSCF calculations to elucidate the intricate mechanisms regulating the intramolecular photo-(3 + 2)-cycloaddition reactions for the synthesis of 1-aminoNB in the presence or absence of the Ir-complex-based photocatalyst. Our investigations delve into radical cascades, stereoselectivity, particularly single-electron-transfer (SET) events, etc. Furthermore, we innovatively introduce and compare two SET models integrating Marcus electron-transfer theory and transition-state theory. These models combined with kinetic data contribute to recognizing the critical control factors in diverse photocatalysis, thereby guiding the design and manipulation of photoredox catalysis as well as the improvement and modification of photocatalysts. Intramolecular force ; Cycloaddition ; Electron transfer ; Photocatalysis ; Photoredox catalysis ; Chemistry ; Photochemistry ; Organic synthesis ; Catalysis ; Computational chemistry ; Combinatorial chemistry ; Nanotechnology ; Materials science ; Stereochemistry ; Organic chemistry Radical Photochemical Reactions ; CO2 Reduction Techniques and Catalysts ; Sulfur-Based Synthesis Techniques
Authors: Anastasia Rapeyko | J. C. Díaz Infante | Francesc X. Llabrés i Xamena
Source: Molecular Systems Design & Engineering (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Zr-containing UiO-66 metal–organic frameworks as efficient heterogeneous catalysts for glycerol valorization: synthesis of hyacinth and other glyceryl acetal fragrances Zr-containing UiO-66 compounds are effective and reusable heterogeneous catalysts for glycerol valorization into glyceryl acetal fragrances. Glycerol ; Hyacinth ; Catalysis ; Acetal ; Metal-organic framework ; Chemistry ; Heterogeneous catalysis ; Organic chemistry ; Adsorption Metal-Organic Frameworks: Synthesis and Applications ; Chemical Synthesis and Reactions ; Covalent Organic Framework Applications
Authors: Alexander A. Kirichok | Tatyana V. Yegorova
Source: French-Ukrainian Journal of Chemistry (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Functionalized Derivatives of 2-azaspiro[3.3]heptane-1-carboxylic Acid and 7-oxa-2-azaspiro[3.5]nonane-1-carboxylic Acid for Drug Design 2-azaspiro[3.3]heptane-1-carboxylic acid and 7-oxa-2-azaspiro[3.5]nonane-1-carboxylic acid, which had been reported as bioisoster of well-known pipecolic acid, were subjected to chemical transformations, resulting in a number of functionalized derivatives. The obtained molecules contained diversified functional groups, allowing their incorporation in bioactive compounds in versatile modes. Described synthetic approaches afforded multigram-scaled synthesis of the desired compounds with good yields, thus being applicable in drug design Carboxylic acid ; Nonane ; Heptane ; Chemistry ; Organic chemistry ; Pipecolic acid ; Combinatorial chemistry ; Amino acid ; Biochemistry Asymmetric Synthesis and Catalysis ; Chemical Synthesis and Analysis ; Synthetic Organic Chemistry Methods
Authors: Dibya Jyoti Borah | D. Saikia | Alok Kumar Das | Prasanta Kumar Saikia | A.T.T. Mostako
Source: Discover Materials (article, 2023-04-07)
Field: Materials Science — Materials Chemistry

An investigation on the structural and optical properties of mercaptosuccinic acid capped cadmium telluride quantum dots Abstract In this work, a sonication induced modified wet chemical approach is adopted to synthesize highly luminescent and water soluble cadmium telluride (CdTe) quantum dots (QDs). The morphology, size, crystal structural, and optical properties of CdTe QDs are investigated for different refluxing time (1–4 h). The refluxing time-dependent optical constants viz. band gap energy and Urbach energy of the QDs are estimated from UV–Visible absorption spectra. The optical band gap energy decreased from ~ 2.12 to 1.92 eV and the Urbach energy increased from ~ 361 to 487 meV, with the increase in refluxing time. CdTe QDs are found to be uniform in size. The average size of the QDs estimated from the High Resolution Transmission Electron Microscope image analysis is about 5.8 and 8.2 nm for refluxing times 1 and 4 h, respectively. The growth mechanism of the QDs as a function of refluxing time has also been discussed. The fluorescence spectra of the QDs, revealed emission peaks having wavelength from ~ 534 to 585 nm, under the excitation wavelength of 320 nm. The fluorescence emission peaks showed a bathochromic shift with increasing refluxing time. CdTe QDs also exhibit excitation-dependent fluorescence behaviour. Two crystalline phases of the CdTe QDs, namely hexagonal and cubic are confirmed from the High Resolution Transmission Electron Microscope images and Selected Area Electron Diffraction patterns analysis. The phase transformation from hexagonal to cubic is successfully achieved by tuning the refluxing time from 1 to 4 h. Quantum dot ; Cadmium telluride photovoltaics ; Band gap ; Transmission electron microscopy ; Analytical Chemistry (journal) ; Materials science ; Bathochromic shift ; Hexagonal phase ; High-resolution transmission electron microscopy ; Fluorescence ; Absorption (acoustics) ; Luminescence ; Photoluminescence ; Absorption spectroscopy ; Chemistry ; Optoelectronics ; Crystallography ; Nanotechnology ; Optics ; Hexagonal crystal system Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Nanocluster Synthesis and Applications
Authors: Shailendra Kumar Sharma | Bernt Johannessen | Vladimir B. Golovko | Aaron T. Marshall
Source: Inorganics (article, 2023-04-28)
Field: Materials Science — Materials Chemistry

X-ray Absorption Spectroscopy of Phosphine-Capped Au Clusters The structural determination of ultrasmall clusters remains a challenge due to difficulties in crystallisation. Often the atomically precise clusters undergo structural change under the influence of the environment. X-ray absorption spectroscopy (XAS) can be an attractive tool to study the electronic and geometric properties of such clusters deposited onto various supports under in situ conditions. Herein, [Au6(dppp)4](NO3)2, [Au9(PPh3)8](NO3)3, [Au13(dppe)5Cl2]Cl3, and Au101(PPPh3)21Cl5 clusters were studied using XAS. The clusters exhibited distinct features compared to bulk gold. XANES results show a systematic increase in the absorption edge energy and white line intensity, with a decrease in cluster nuclearity. The EXAFS of clusters are sensitive to nuclearity and ligands and were fitted with their known crystal structures. This study advances the understanding of the phosphine-ligated metal clusters relevant to practical applications in catalysis and sensing. X-ray absorption spectroscopy ; Extended X-ray absorption fine structure ; XANES ; Cluster (spacecraft) ; Absorption spectroscopy ; Absorption (acoustics) ; Spectroscopy ; Phosphine ; Materials science ; Crystallography ; Chemistry ; Catalysis ; Optics ; Physics Nanocluster Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: P. Babuji | Md Abu Taher | Mudasir H. Dar | D. Narayana Rao | P. Gopala Krishna | V. Saikiran
Source: Photonics (article, 2023-12-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Surface-Enhanced Raman Scattering Studies of Au-Ag Bimetallic Nanoparticles with a Tunable Surface Plasmon Resonance Wavelength Synthesized by Picosecond Laser Irradiation Here, we present a simple and green method of preparing Au-Ag bimetallic nanoparticles (NPs) with a tunable surface plasmon resonance (SPR) wavelength by using picosecond laser irradiation. Au-Ag alloy NPs have been produced by irradiating the solutions containing respective metallic salts in a polyvinyl alcohol (PVA) matrix using a picosecond laser in a single-step process. The SPR wavelength of the Au-Ag bimetallic NPs is observed to be shifted/changed with the Au-Ag concentration and the laser irradiation parameters. The Au-Ag NPs embedded in the PVA matrix are advantageous for Surface-Enhanced Raman scattering (SERS) applications. The estimated enhancement factors (EFs) were observed to vary as a function of conditions of the Au-Ag bimetallic alloy NPs synthesis and also on the concentration of Au at a fixed input fluence of irradiation. The SERS active platforms of Au-Ag bimetallic NPs showed EFs as high as of the order of 108 for Crystal Violet (CV) dye samples at nano molar concentrations. The present study demonstrates a simple, single-step, and green method that fabricates Au-Ag alloy-based nanocomposites suitable for SERS investigations with significantly higher orders of EFs. Bimetallic strip ; Materials science ; Surface plasmon resonance ; Raman scattering ; Fluence ; Picosecond ; Nanoparticle ; Irradiation ; Raman spectroscopy ; Plasmon ; Nanocomposite ; Laser ; Analytical Chemistry (journal) ; Optoelectronics ; Nanotechnology ; Metal ; Optics ; Chemistry ; Organic chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Laser-Ablation Synthesis of Nanoparticles ; Nonlinear Optical Materials Studies
Authors: Yuya Inaba | Jian Yang | Yu Kakibayashi | Tomoki Yoneda | Yuki Ide | Yuh Hijikata | Jenny Pirillo | Ranajit Saha | Jonathan L. Sessler | Yasuhide Inokuma
Source: Angewandte Chemie (article, 2023-02-14)
Field: Materials Science — Materials Chemistry

Chiral Calix[3]pyrrole Derivatives: Synthesis, Racemization Kinetics, and Ring Expansion to Calix[9]‐ and Calix[12]pyrrole Analogues Abstract Chiral pyrrolic macrocycles continue to attract interest. However, their molecular design remains challenging. Here, we report a calixpyrrole‐based chiral macrocyclic system, calix[1]furan[1]pyrrole[1]thiophene ( 1 ), synthesized from an oligoketone. Macrocycle 1 adopts a partial cone conformation in the solid state, and undergoes racemization via ring inversion. Molecular dynamics simulations revealed that inversion of the thiophene is the rate determining step. Pyrrole N ‐methylation suppressed racemization and permitted chiral resolution. Enantioselective N ‐methylation also occurred in the presence of a chiral ammonium salt, although the stereoselectivity is modest. A unique feature of 1 is that it acts as a useful synthetic precursor to yield several calix[ n ]furan[ n ]pyrrole[ n ]thiophene products ( n =2–4), including a calix[12]pyrrole analogue that to our knowledge constitutes the largest calix[ n ]pyrrole‐like species to be structurally characterized. Racemization ; Thiophene ; Pyrrole ; Chemistry ; Calixarene ; Enantiomer ; Supramolecular chemistry ; Ring (chemistry) ; Enantiopure drug ; Enantioselective synthesis ; Stereochemistry ; Organic chemistry ; Molecule ; Catalysis Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection ; Surface Chemistry and Catalysis