Applied Organometallic Chemistry最新文献

Phosphate and pyrophosphate can advance green chemistry as nontoxic and sustainable catalysts. This study presents the development of a novel series of solid composite catalysts, comprising AlCl₃ and alkaline-earth metal (pyro)phosphates. The efficacy of these catalysts in facilitating the hydrosilylation of olefins with hydrosilanes has been thoroughly examined. Adding aluminum chloride enhances the catalytic activity of calcium phosphate for the catalysis hydrosilylation reaction, enabling efficient conversion of various linear alkenes into corresponding adducts with excellent yields. Furthermore, this catalytic system exhibits remarkable stability, maintaining its activity over 15 cycles without significant decrease.

Under ultrasonication, the nanoscale supramolecular complex [Pb (QCA)₂]_n (NSC1) was formed by the self-assembly of lead nitrate and quinoline-2-carboxylic acid (QCA) as linking ligand. Pb^II exhibits a (O₂N₂) distorted square planner geometry, where the Pb^II atom coordinates to two QCA ligands, according to single crystal X-ray diffraction of 1. With a packing structure of 1, facing molecules are arranged in parallel planes and joined by multiple H-bonds and π-π stacking to form a three-dimensional network. NSC1 was examined using a variety of structural characterization techniques as well as spectrum studies. Despite the well-documented toxicity of lead, which is utilized in various products, the nanoscale supramolecular complex [Pb (QCA)2]n (NSC1) demonstrates considerable safety owing to its stability, remaining unaffected by degradation mediums, as corroborated by different techniques. So, under UV or ultrasonic wave conditions, it has been demonstrated that the heterogeneous catalyst NSC1 exhibits significant catalytic activity in presence of H₂O₂ against the breakdown of the indicated pollutants, indigo carmine (IC) and phenol (Ph), in very short times. Using the disodium salt of terephthalic acid, the photoluminescence probing method was applied to ascertain the reactive oxygen species and the reaction process mechanism.

The composite material featuring a magnetic core-shell structure, designated as Fe₃O₄@MnO₂@polydopamine (PDA), has been synthesized for the purpose of eliminating methylene blue (MB) and malachite green (MG) dyes from aqueous solutions. This composite is characterized by the hydrothermal assembly of densely packed manganese dioxide (MnO₂) nanosheets onto Fe₃O₄ microspheres, resulting in a significant enhancement of the composite's specific surface area. The encapsulated PDA exhibits a significant presence of nitrogen and oxygen elements, which serve as active sites for dye adsorption. At a temperature of 298.15 K, the adsorption capacities for MB and MG are measured at 50.17 and 48.73 mg g⁻¹, respectively. Furthermore, at 308.15 K, the adsorption efficiencies for MB and MG are recorded at 98.55% and 97.84%, respectively. The test results indicate that the adsorption behavior is characterized as chemisorption. Furthermore, it adheres to the pseudo-second-order kinetic model and the Langmuir isotherm model across various temperatures. The overall process is identified as a spontaneous endothermic reaction, with the rate primarily influenced by micropore diffusion and the equilibrium adsorption associated with intraparticle diffusion. Following the desorption treatment, Fe₃O₄@MnO₂@PDA continues to exhibit effective adsorption capabilities for MB and MG dyes, indicating significant practical application potential.

The CdSe nanocrystals were synthesized in an aqueous medium containing mercaptosuccinic acid (MSA). The X-ray diffraction study verifies that CdSe-MSA has a cubic phase. Scanning electron microscopy (SEM) images show an array of approximately spherical nanoparticles with very small sizes. The electrical and dielectric properties of these nanocrystals were studied using the complex impedance method. By analyzing Nyquist diagrams, we derived the equivalent circuit consisting of R//C//CPE for temperaturesT ≤ 413 K, with a Warburg element appearing for T > 413 K, confirming the diffusion of MSA on the surface of the nanocrystals. The relaxation time (τ) was deduced by analyzing the spectra of M" using the Bergman equation, which is defined by an activation energy (Ea) of 0.743 eV. The conductivity follows Jonscher's power law, with DC conductivity (σ_DC) increasing in phase I (T ≤ 413 K) and decreasing in phase II (T > 413 K). The variation of s as a function of temperature shows that the conductivity adheres to the single CBH model in the semiconductor domain. It is observed that the hopping distance (R_W) decreases with temperature and frequency, which explains the increase in charge carriers and the rise in conductivity in this temperature range.

Two transition metal complexes (complex 1 = {[Cd (DCPP)·(H₂O)]·(DMF)}_n and complex 2 = {[Ni (DCPP)·(H₂O)]·(DMF)}_n) with the same structure and different functions were synthesized based on 2,6-bis(4′-carboxybenzene)pyrazine ligand (H₂DCPP) by solvothermal method, and their structure and properties were analyzed and characterized by a variety of characterization methods. Complex 1 was used as a fluorescence sensor to recognize cations and anions in water; it had excellent recognition and anti-interference ability with Fe³⁺ and Cr₂O₇²⁻ among cations and anions. Complex 2 (2-CPE) was used as electrochemical material to perform electrochemical tests on hydrogen peroxide and sodium nitrite with good electrocatalytic effect. This work provides a synthesis strategy for fluorescence and electrochemical sensing materials, respectively.

The inability to recycle Fenton reagents and a narrow pH range restricts hematite (Fe₂O₃) application in the actual photo-Fenton system. The engineering of surface structures is identified as an effective approach for enhancing the photo-Fenton activity of the material. In this work, three different morphologies (nanosheet, cube, and ring) Fe₂O₃ materials containing oxygen vacancies (OVs) were synthesized by hydrothermal method, and a novel system for the photo-Fenton degradation of sulfamethazine was examined. In the presence of oxalic acid, the Fe₂O₃/oxalic acid heterogeneous catalytic system demonstrated the in situ generation of H₂O₂ and facilitated Fenton-like reactions. The as-prepared nanosheet-Fe₂O₃ showed the highest photo-Fenton degradation efficiency. The free radical capture experiment was investigated by using different free radical sacrificial agents, and the results suggested that superoxide radicals were the principal active species involved. Ecotoxicity assessments utilizing toxicity prediction software assessed the reaction intermediates generated during sulfamethazine degradation via a quantitative structure–activity relationship method, indicating that these intermediates exhibited reduced developmental toxicity. The possible pathways of sulfamethazine degradation and mechanism for synergistic degradation sulfamethazine effect between Fe₂O₃ and oxalic acid were proposed. This research presents an effective strategy for the design and synthesis of Fe₂O₃ photocatalysts with various morphologies and oxygen vacancies, suitable for application in photo-Fenton catalysis and related environmental contexts.

This study synthesized 1,2,4-triazines, a novel class of derivatives, with a high efficiency using a multicomponent reaction. The reaction involved oxoindolinylidene malononitrile, ethyl 2-arylamino-4-dioxo-4-arylbutanoates, and hydrazonoyl chlorides in an aqueous solution at room temperature. The reaction was facilitated by the presence of Ag/Fe₃O₄@MWCNTs MNCs. This study examines the antioxidant properties of 1,2,4-triazine in addition to the other research undertaken in this work. Using the MTT test, the cytotoxic properties of all the produced compounds were assessed in vitro against cancer cell lines (MCF-7 and A549) and normal cell lines (BEAS-2B). It was discovered that the most effective cytotoxic agent, doxorubicin like in its lack of selectivity, was Derivative 4e. On the other hand, Compound 4b might be regarded as an equipotent molecule with greater selectivity in relation to doxorubicin. The production process of 1,2,4-triazine demonstrated several advantageous features, including rapid reactions, high yields of the final product, and straightforward separation of the catalyst and product from the reaction mixture.