Journal of Chemical Sciences最新文献

This work delves into the utility of chromium’s X-ray fluorescence (XRF) lines for the analysis of chromite ores, employing a wavelength-dispersive XRF spectrometer. The CrLα_1,2 and CrLβ₁ fluorescence lines, despite not involving electronic transitions from valence to K-core shell, offer substantial insights into the valence state of chromium. This study examines these relatively unexplored but potentially valuable lines and compares them with the CrKβ series fluorescence lines. Intriguingly, our investigation reveals striking differences in the L-line fluorescence spectra between metallic chromium (Cr(0)), chromite ores (Fe, Mg)Cr₂O₄, and K₂Cr₂O₇. Chemical shifts and peak shapes emerge as key discriminators, surpassing the sensitivity of the CrKβ_1,3 lines. Notably, the chemical shifts of L-lines are amplified, showcasing a clear trend: Cr(III) exhibits a larger shift than Cr(VI), mirroring the pattern observed in the Kβ-lines. The fluorescence peak shapes of Lα_1,2 and Lβ₁ for metallic chromium and chromite ores (both have unpaired 3d-electrons) are similar, whereas those of K₂Cr₂O₇ differ considerably in peak shape, indicating that unpaired 3d-electrons influence these peaks. A linear relationship was found between the area under the curve ratio for Lα_1,2 and Lβ₁ and the valence state of chromium.

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Herein, we report the novel protocol for synthesizing bimetallic gold and palladium nanoparticles decorated on rigid and stable cerium oxide support using aloe vera extract. The Au–Pd@CeO₂ catalyst was found to be effective for the Buchwald–Hartwig C–N cross-coupling reaction and amination of benzyl alcohol due to the synergistic influence generated by Au and Pd metals. The prepared catalyst was characterized by using XRD, TEM, SEM, and EDS. The catalyst can be efficiently used for a diverse range of substrates in the Buchwald–Hartwig C–N cross-coupling and amination of benzyl alcohol reactions compared to previously described protocols. The catalyst retains its catalytic activity even after seven cycles.

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The synthesis of bimetallic gold and palladium nanoparticles decorated on cerium oxide support using aloe vera extract. The Au-Pd@CeO₂ catalyst was found to be effective for Buchwald–Hartwig C-N cross-coupling and amination of benzyl alcohol reactions due to the synergistic effect generated by Au and Pd metals.

Potassium tert-butoxide mediated a direct one-pot synthesis of diversely substituted nitriles from aldehydes via the sequential addition of hydroxylamine and benzoyl chloride is reported. A wide range of aromatic, heteroaromatic, and vinyl aldehydes were converted into corresponding nitriles in good to excellent yields. Room temperature reactions, transition metal-free conditions, wide functional group tolerance, simple operation, and short reaction time are the salient features of the developed methodology.

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An efficient base-mediated a direct synthesis of aromatic and heteroaromatic nitriles from corresponding aldehydes was reported. As the starting ingredients for the synthesis, aldehyde, and hydroxylamine were combined with benzoyl chloride in a series of reactions. Notably, this process may be carried out at room temperature without the need for transition metal catalysts, making it a practical and effective process. A wide variety of aromatic and heteroaromatic aldehydes gave the products in good to excellent yields. Broad substrate scope, easy operation, quick reactions, tolerance of different functional groups, and room temperature reactions are the important features of the developed methodology.

In the context of solid-state electrolytes for batteries, ambient temperature ionic conductivity stands as a pivotal attribute. This investigation presents a compilation of potential candidates for solid-state electrolytes in lithium-ion batteries, employing clustering—an unsupervised machine-learning technique. To achieve this, a fusion of data from two distinct datasets was undertaken: a smaller dataset consisting of 51 compounds endowed with experimental lithium-ion conductivity data and a substantially larger dataset of 15,530 compounds devoid of such information. The compounds in our dataset were divided into various groups based on several characteristics that influence the conductivity of lithium-ion batteries. Then, the location of the compounds known to have high lithium-ion conductivity (>10⁻⁴ S cm⁻¹) at room temperature was observed. The 427 compounds (i.e., unique material project IDs) found in the same cluster as most of these high-conducting compounds are then further examined. This paper concludes by offering a catalog of solid-state compounds that can be utilized to choose compounds for solid-state electrolytes in batteries.

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Synopsis: The above plot shows the 15530 lithium-based compounds clustered into 7 clusters based on several factors that were identified to affect lithium-ion conductivity. We observe the location of the already known good lithium-ion conductors (represented by the golden stars) to identify other similar compounds.

The synthesis of amantadine hydrochloride from 1-bromoadamantane utilizing urea and methanol is described as a one-pot, efficient, and sustainable process by optimizing reaction conditions. This method employs a phase transfer catalyst, TBAI, and in situ salt formation with HCl, resulting in the desired product with enhanced yield and purity.

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The synthesis of amantadine hydrochloride from 1-bromoadamantane utilizing urea and methanol is described as a one-pot, efficient, and sustainable process through the optimization of reaction conditions. This method employs a phase transfer catalyst, TBAI, and in situ salt formation with HCl, resulting in the desired product with enhanced yield and purity.

Organic near-infrared (NIR) photothermal agents have tremendous potential in cancer therapy. Herein we report anovel NIR light responsive photothermal agent DDHT/F127 micelles, which has excellent photothermal properties and photostability, along with outstanding outcomes in cancer phototherapy.

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A novel donor-acceptor (D-A)-type organic photothermal material 5,18-dibutyl-5,18- dihydro-diquinoxaline[2,3-a:2',3'-c]-phenazine (DDHT) was encapsulated with Pluronic^® 127 (F127) material to form NIR light responsive photothermal agent DDHT/F127 micelles, which has excellent photothermal properties with photothermal conversion efficiency of 51.55% under 655 nm NIR laser irradiation, along with outstanding outcomes in cancer therapy.

The unique properties of hydroxyl-terminated polybutadiene (HTPB) make it suitable for use in various fields. Because it is impossible to use external factors to repair the damage caused by HTPB polymer in all places, it is very useful to create intrinsic self-healing properties. In this study, HTPB polymer became intrinsically self-healing during three stages of hydrobromination, amination, and the addition of 2-ureido-4-pyrimidinone groups. ATR and NMR analysis confirmed the formation of intermediates and the final self-healing compound. Also, DSC analysis showed that the glass transition temperature of the resin, which is its most important feature, has not changed. After self-healing HTPB was synthesized, this resin was mixed with isophorone diisocyanate and coated on a glass slide. The cured polyurethane coating was scratched, and an optical microscope monitored the healing process for 24 h. The corrosion test of metal plates confirmed the creation of self-healing properties in the resin. The places of scratches created on the control sample were rusted in the sodium chloride solution, while the plates with modified resin coating did not show this issue.

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HTPB polymer becomes intrinsically self-healing during three stages of hydrobromination, amination, and the addition of 2-ureido-4-pyrimidinone groups. These groups have a great tendency to form hydrogen bonds and give intrinsic self-healing properties to the resin. Self-healing HTPB can repair damage without the need for an external agent.

Microbial resistance is a growing threat to all of us worldwide. The need for rapid pharmaceutical solutions is a challenge for chemists. Computer-aided tools and molecular docking provide a speedy root for designing and investigating new metal-based drugs. Given this, the tris(hydroxamato)vanadium(III) complexes of composition [V(HL^1–2)₃] (I, II) (HL¹ (=) 4-NO₂C₆H₄CONHO⁻; HL² (=) 2-Cl-4-NO₂C₆H₃-CONHO⁻) have been synthesized by the reactions of VCl₃ with three equivalents of different potassium hydroxamate ligands in dry methanol. Elemental analyses, molar conductivity, molecular weight determination, magnetic moment measurements and IR, UV-Vis spectral studies, and mass spectrometry have characterized complexes. The magnetic moment and electronic spectra are consistent with the +3 oxidation state of vanadium. Based on physicochemical and spectral techniques, a distorted octahedral geometry around vanadium has been proposed for complexes. The electrochemical behavior of complexes studied by cyclic voltammetry has displayed a quasi-reversible V^IV/V^III redox couple. Molecular docking studies were conducted against the Klebsiella pneumoniae modA protein; complexes showed higher binding free energies than free ligands, displaying efficient binding at the protein groove. Therefore, the MIC method has evaluated free ligands and complexes for in vitro antimicrobial activity against bacteria and fungi.

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In this paper, we report the synthesis and the structure–activity relationship study of three hydrazone analogs; the Schiff base hydrazone SBH and 2, 4-dinitrophenylhydrazones H1 & H2 derived from (E)-chalcones, to identify the active fragment of each structure. This identification has been carried out following in vitro biological evaluation, which revealed that the analogs H1 and H2 showed significant antibacterial activity due to their (E)-chalcone fragments characterized by proton NMR data and demonstrated by the docked view with emphasis on the involvement of these moieties in the interaction with the DNA gyrase, and thus contributes to the pharmacophore modeling. At the same time, SBH exhibited the highest free radical DPPH scavenging power associated with hydrogen bonding and conjugated push−pull chromophores, which were elucidated by reported vibrational assignments and absorption spectra. The DFT optimizations gave rise to non-planar and distorted structures around the hydrazone group with comparable geometrical parameters. The chemical descriptors predict comparable biological activities, while the BDE necessary for the H-abstraction indicated the best antioxidant activity for the Schiff base hydrazone SBH compound.

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2, 4-Dinitrophenylhydrazone analogs with (E)-chalcone and/or push-pull moieties were synthesized and characterized. The in-vitro and in-silico studies were carried out both to find the structure-activity relationship and to model the pharmacophore.