Chemical Papers最新文献

This study focuses on the metathesis of 2-butene to convert low value products into higher value propylene. In this work, using machine learning (ML) techniques, several robust models were built and developed to predict the mole fraction of components in products of catalytic metathesis process over WO₃ on mesoporous support without the need for profound knowledge about exact reaction mechanism and their kinetics. The operative parameters were reaction temperature and residence time. The process performance was assessed using conversion and product selectivity as responses. Cross-validation technique was used during the model development. The developed models were used to investigate the mechanism of process as well as examining the effects of operative parameters on process performance. Further, these models were used to optimize the process in companion with genetic algorithm (GA).

The reaction of copper(I) thiocyanate (CuSCN) with triphenylphosphine (PPh₃) and 2,2’-dipyridylamine (dpa) in acetonitrile, at room temperature for just two hours, led to the formation of the photoluminescent complex [Cu(SCN)(PPh₃)(dpa)], which exhibits intense blue-green photoluminescence in the solid state. This synthesis route represents an advancement over previously reported method that required longer reaction time and different solvent, thus offering a more efficient and practical approach. Single-crystal X-ray diffraction revealed a novel crystal structure featuring a slightly distorted tetrahedral geometry around the Cu(I) center, stabilized by P, N, and S donor atoms from the ligands and thiocyanate. The resulting Cu(I) complex was applied to fluorescent detection studies and showed a strong affinity for the pharmaceutical analytes sodium diclofenac and tetracycline hydrochloride. This interaction was evidenced by significant fluorescence quenching, low limits of detection (LOD) of 3.14 µM for sodium diclofenac and 0.33 µM for tetracycline hydrochloride, and high binding constants (K_b) of 0.00714 µM⁻¹ and 0.00425 µM⁻¹, respectively. The complex exhibited a linear fluorescence response within relevant concentration ranges, suggesting excellent sensitivity and potential applicability for detecting trace pharmaceutical residues. These findings highlight the promise of this complex as a practical and efficient sensor, with implications for environmental monitoring and pharmaceutical quality control.

High-value-added sulfur products as well as hydrogen (H₂) can be obtained by electrolytic oxidation of hydrogen sulfide (H₂S), which is a promising energy conversion technology that contributes to the resource utilization of the pollutants. In conventional sulfide oxidation reaction (SOR), the recovery of the anodic product typically requires additional acidification treatment, resulting in the unsustainable use of electrolyte. Here, a novel H₂S direct electrolysis system with ionic liquid (IL)-based electrolyte, consisting of acetate-based ILs and NaOH aqueous solution, was investigated. Compared to single NaOH aqueous solution, [Hmim]Ac-based electrolyte showed high H₂S absorption capacity and best electrochemical performance for SOR. Significantly, the anodic sulfur product was proved to be α-sulfur, which could be self-precipitated from the electrolyte without extra acid. The [Hmim]Ac-based electrolyte has the highest equilibrium solubility of sulfur (30.8 g L⁻¹), which was 2–3 times that of the conventional electrolyte of NaOH aqueous solution. It is mainly attributed to the synergistic coupling of ILs and NaOH for H₂S absorption and the modulating effect of ILs. Under constant potential electrolysis at 1.2 V vs RHE in [Hmim]Ac-based electrolyte, the maximum current density reached 194.4 mA cm⁻², the maximum hydrogen production rate reached 3945 μmol h⁻¹, the Faraday efficiency reached 97.9%, and the sulfur recovery of 82.6%. The IL-based electrolyte can be reused for at least three cycles of absorption-electrolysis, holding promise for efficient and continuous electrolysis of H₂S.

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In this manuscript, we report a novel cytotoxic Ru (II) macrocyclic complex i.e., [C₁₈H₂₄N₃O₃RuCl₂]Cl₂, synthesized via template condensation reaction of 5-chloroisatin with 1,13-diamino-4,7,10-trioxatridacane in the presence of RuCl₃.xH₂O metal salt as template, under an ethanolic medium with a 1:1:1 molar ratios. The structural scaffolding of the complex has been confirmed by elemental analysis, NMR, UV, IR, mass spectrometry, and X-ray diffraction. In accordance with these spectral studies and XRD, an octahedral geometry has been proposed for the complex with 5.89 nm and 1.11 nm average crystalline size as calculated by Debye–Scherrer and Williamson–Hall plot methods respectively. Furthermore, the metal complex has been screened for antifungal and antibacterial activities. Biological evaluations revealed significant antimicrobial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacterial strains, as well as fungal pathogens Aspergillus niger and Penicillium chrysogenum. The anticancer potential of the synthesized complex has also been analysed against MCF-7 (Human breast adenocarcinoma) cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and the result revealed the noteworthy potential of the complex as cytotoxic agent. These findings underscore the potential of this ruthenium (II) complex as a dual-action antimicrobial and anticancer agent, warranting further investigation for therapeutic applications.

Recent advances in porous, nanoscale two-dimensional materials have highlighted their exceptional potential in various scientific fields, including energy storage, gas capture, and molecular transport. Among these materials, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have garnered considerable interest due to their tunable porosity, large surface areas, and ability to form hybrid structures with enhanced functionalities. In this study, we systematically analyze the structural properties of these frameworks through topological indices derived from M-polynomials. The indices considered include Zagreb, Randic, symmetric division, forgotten, harmonic, inverse sum, and both third and fifth symmetric division indices. We apply this framework to two n-dimensional hexatriphenylene-based networks, one metal–organic and the other covalent, and perform a comparative analysis of the resulting M-polynomial-based indices to reveal their structural characteristics and offer insights into their chemical behavior.

Integrating with microwave-assisted extraction, deep eutectic solvents present a sustainable and efficient alternative to conventional organic solvents for extracting polyphenols from Azadirachta indica leaves. Choline chloride-ethylene glycol at various mole ratios and water contents was evaluated for its effectiveness in extracting polyphenol compounds. The results demonstrated that the interaction between leaves, water, and deep eutectic solvents significantly affected the total phenolic content. A precise optimisation of deep eutectic solvent extraction, employing a 1:3.5 or 1:6 molar ratio, a 12.5 feed-to-solvent ratio, and 17.5% water, yielded maximum phenolic compound extraction, characterised by Folin–Ciocalteu quantification and confirmed via GC–MS identification of key phenolic classes, corroborated by FTIR spectral analysis of relevant functional groups. Deep eutectic solvent-assisted microwave-assisted extraction demonstrates exceptional promise as a sustainable methodology for optimising polyphenol recovery from Azadirachta indica foliage, as evidenced by our comprehensive investigation. Microwave-assisted extraction supports sustainability by enhancing energy efficiency, promoting circular economies, and upcycling waste into polyphenols using water-based solvents. A radial-basis artificial neural network was employed to develop a prediction model for total phenolic content, and it successfully predicted the total phenolic content values with an average error of 4.81%.

Oxidation remains a critical degradation issue in marine, aircraft, land-based gas turbines, and industrial systems, primarily due to the combined effects of high operating temperatures and diverse fuel types. This study examines how Fe–35Ni–22Cr (F35N22C) and Fe–17Ni–18Cr (F17N18C) alloys oxidize at high temperatures when exposed to dry air for 50 h at 700 °C, 800 °C, and 900 °C. Oxidation kinetics were evaluated through weight change measurements, revealing parabolic behavior. The calculated activation energies were 300 kJ/mol for F35N22C and 277.9 kJ/mol for F17N18C. Corresponding parabolic rate constants at 700 °C, 800 °C, and 900 °C were 2.0 × 10⁻ ⁹, 2.0 × 10⁻ ⁹, and 1.0 × 10⁻ ⁶ g²/cm⁴·h for F35N22C, and 3.0 × 10⁻ ⁹, 1.0 × 10⁻ ⁹, and 4.0 × 10⁻ ⁷ g²/cm⁴·h for F17N18C. Phase identification and microstructural characterization were conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX). The formation of oxide scales rich in Fe₂O₃, Fe₃O₄, Cr₂O₃, NiCr₂O₄ spinel, and austenite contributed to the alloys’ oxidation resistance. SEM, spot-EDX, line scans, and elemental mapping of surface and cross-sections revealed the structural evolution of the oxide layers under different temperatures and durations. These findings enhance the understanding of protective scale formation and support the development of Fe-based alloys for high-temperature applications.

Lead-free halide double perovskites have attracted considerable attention due to their promising optoelectronic and thermoelectric properties. In this work, density functional theory (DFT)-based simulations using WIEN2k code were performed to investigate the structural, optical, elastic, electronic, thermodynamic, thermoelectric, and photocatalytic properties of vacancy-ordered Na₂Sn(Cl/Br)₆ perovskites. The full-potential linearized augmented plane wave (FP-LAPW) method was employed to accurately evaluate their physical properties. Both compounds exhibit direct band gaps of 2.77/1.12 eV (GGA), 3.63/2.40 eV (GGA + SOC), and 3.98/3.28 eV (hybrid HSE06), respectively, along with strong optical absorption of 64.3 × 10⁴ cm⁻¹ and 60.3 × 10⁴ cm⁻¹ in the visible/ultraviolet region of the light spectrum, making them promising candidates for photovoltaic and optoelectronic applications. Structural and thermodynamic stability is confirmed through tolerance factors of 0.90 and 0.89, negative formation energies of − 1.9174 and − 0.1673, respectively, phonon and ab initio molecular dynamic simulations, and thermodynamic assessments. Elastic and mechanical parameters reveal their ductile and anisotropic mechanical character. Moreover, high Seebeck coefficients of 1550/1580 in the n-type/p-type region for Na₂SnCl₆ and 973/765 in the n-type/p-type region for Na₂SnBr₆, notable electrical conductivity of 2.34 × 10¹⁹/2.12 × 10²⁰ in n-type/p-type region for Na₂SnCl₆ and 1.16 × 10²⁰/3.60 × 10²⁰ in n-type/p-type region for Na₂SnBr₆, and ZT (0.44 and 0.37) underscore their potential for thermoelectric device applications. Band-edge alignment under different exchange–correlation functionals, especially for the PBE-GGA functional, with water redox potentials further suggests their suitability for solar-driven hydrogen evolution, positioning them as multifunctional materials for sustainable energy technologies.

In this study, the biosorption processes of Methylene Blue (MB), Basic Blue 41 (BB41), Reactive Red 120 (RR120), Methyl Red (MR) and Trypan Blue (TB) dyes were investigated using Suillus collinitus (S. collinitus). Scanning electron microscopy (SEM), isotherm, kinetic and thermodynamic, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses were performed to determine the biosorption mechanism and characterization. Optimization of factors such as initial dye concentration, adsorbent’s dose, reaction time, pH and temperature affecting the biosorption process was carried out. The highest removal efficiencies were obtained for MB and BB41, 82.52% and 88.224%, respectively. The biosorption capacities of MB, BB41, RR120, MR and TB dyes were 61.35, 123.46, 56.82, 50.00, and 54.35 mg/g, respectively. The adsorption equilibrium data showed best fit to the Temkin isotherm for MB and MR, the Freundlich isotherm for BB41 and RR120, and the Dubinin–Radushkevich (D–R) isotherm for TB. The kinetic model that best explained the biosorption process for all dyes was pseudo-second-order (R² > 0.99). Thermodynamic analyses showed that biosorption was exothermic (ΔH^o < 0) for MB and BB41 and endothermic (ΔH^o > 0) for RR120, MR and TB; however, the enthalpy values remained below 40 kJ/mol for all dyes, indicating that physisorption is the dominant mechanism. Gibbs free energy change (ΔG^o) was negative at all temperatures, confirming that the biosorption process was spontaneous. It offers a sustainable biosorbent alternative thanks to its high surface area, natural porosity structure and low cost.

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Issues such as Zn dendrites, hydrogen evolution reactions (HER), self-corrosion, and Zn anode passivation significantly hinder the development of Zn-ion batteries. In this study, Na₂SeO₃ was introduced into the ZnSO₄ electrolyte and NaCl solution to reduce the rate of hydrogen evolution reaction, thereby inhibiting both HER and self-corrosion in Zn. Experimental results indicate that after prolonged immersion, the surface of metallic Zn with the addition of Na₂SeO₃ remained smooth, whereas the surface without the corrosion inhibitor exhibited significant roughness and obvious signs of corrosion. According to the potentiodynamic polarization test results, Na₂SeO₃ can significantly reduce the overall current density in the cathodic region, indicating its notable inhibition effect on the hydrogen evolution reaction. On the other hand, long-term EIS test results demonstrate that Na₂SeO₃ can increase the low-frequency impedance value of the material, suggesting a substantial reduction in the self-corrosion rate of Zn. The protection mechanism of Na₂SeO₃ operates via two main pathways: (i) competition for electrons between SeO₃²⁻ reduction and hydrogen evolution, and (ii) the formation of a protective selenium-containing film that shields the zinc substrate. The research conducted in this project can provide valuable insights for the electrode protection of metallic Zn in the field of batteries.