Research on Chemical Intermediates最新文献

The green synthesis of nanoparticles using plant extracts has gained significant attention as a sustainable, efficient, and cost-effective route in modern nanotechnology. This study presents the green synthesis of ZnO and Cu-doped ZnO nanoparticles using Justicia adhatoda leaf extract via co-precipitation, achieving over 94% degradation of newly tested dyes. X-ray diffraction analysis confirmed that the nanoparticles exhibited a hexagonal wurtzite structure with crystallite sizes ranging from 21 to 22 nm. According to UV–Visible absorption measurements, the band gap of ZnO (3.1 eV) exhibited a noticeable reduction to 2.9 eV following Cu doping. Fourier-transform infrared spectroscopy showed that the functional groups in the leaf extract played a key role in nanoparticle formation. FE-SEM micrographs indicated nanosheet-to-spherical morphology for ZnO, while Cu doping resulted in predominantly spherical particles. HRTEM analysis confirmed the polycrystalline nature of the nanomaterials. X-ray photoelectron spectroscopy verified the presence of Zn²⁺ and Cu²⁺ oxidation states, demonstrating the successful incorporation of Cu into the ZnO lattice. Zeta potential analysis showed that the ZnO nanoparticles possessed a high negative surface charge. The photocatalytic degradation efficiencies of bromophenol blue and fast green dyes were 96% and 94%, respectively. Furthermore, Cu-doped ZnO exhibited significantly enhanced antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Rhizopus, and Penicillium compared to pure ZnO. Overall, this green synthesis approach demonstrates strong potential for wastewater treatment and offers a sustainable strategy for future household wastewater management.

The design and development of efficient catalytic systems for sustainable chemical reactions and transformations is an essential principle. In the present study, the synthesis and application of a magnetic nanocatalyst for biodiesel production from waste cooking oil via transesterification reaction were presented. The catalyst was prepared from silica-coated copper ferrite nanoparticles functionalized with amine groups (CuFe₂O₄@SiO₂-NH₂). The surface, structural, and functional group properties of the catalyst were carefully investigated using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrational sample magnetometry (VSM). Under the optimized conditions obtained (4 wt% catalyst, 1:12 oil to methanol molar ratio, 65 °C) without the need for high energy consumption and advanced equipment, the catalyst showed significant efficiency in biodiesel production. The catalyst is rapidly recovered by applying an external magnetic field and can be reused over several cycles with little activity loss, demonstrating its stability and practical applicability. This study increases the knowledge on the structure–activity relationship of metal oxide-based nanocatalysts and their performance as reaction intermediates in green catalytic processes, thus promoting the development of sustainable energy conversion systems.

This study presents a novel bimetallic iron–silver phosphate (FeAg(PO₄)₂) nanocatalyst. We detail a one-pot hydrothermal synthesis of FeAg(PO₄)₂, a hetero-structured composite dominated by silver phosphate (Ag₃PO₄) and iron (III) phosphate (FePO₄). Characterization techniques include X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV–Vis diffuse reflectance, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis, transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray mapping, revealing a mesoporous structure with a surface area of 55.60 m²/g and a pore size of 2 nm. Machine learning, particularly the Random Forest Tree model, predicted energy per atom of − 7.17 eV, and a band gap of 1.87 eV, indicating high stability and suitability for catalysis. The nano-catalyst showed high efficiency in synthesizing benzimidazole derivatives (up to 95% yield in 10 min at 60 °C in ethanol) and was reusable for five cycles. It also demonstrated selective fluorescence quenching for L-cysteine detection, with sulfur-containing amino acids exhibiting higher fluorescence. The study concludes with potential applications in pharmaceuticals and sensing, encouraging further research.

This study demonstrates the successful use of polyimide (PI) as a support material to fabricate hierarchical porous V₂O₅@PI composite materials via hydrothermal synthesis followed by calcination. PI support exhibited a distinctive honeycomb-like porous structure. V₂O₅ loading induced a remarkable morphology evolution. The VO50 catalyst (50 wt% V₂O₅ loading) exhibited a “flower-like” microsphere structure composed of assembled nanosheets. XPS analysis confirmed the coexistence of V⁴⁺ and V⁵⁺ species in VO50. Both specific surface area and pore volume were found to decrease gradually with increasing V₂O₅ loading, likely due to the blockage of pores by vanadium species. The developed V₂O₅@PI composite materials were applied to the ammoxidation of p-chlorotoluene for the synthesis of p-chlorobenzonitrile. The VO50 catalyst exhibited outstanding performance under optimized conditions, achieving a yield of 65.5% and a selectivity of 76.3% toward p-chlorobenzonitrile—both significantly higher than those obtained with the unsupported V₂O₅ catalyst. The excellent performance of the VO50 catalyst could be attributed to its stable flower-like morphology, high specific surface area, high dispersion of vanadium species, and full exposure of active sites. The present study demonstrates that PI can serve as an ideal support for high-performance vanadium-based ammoxidation catalysts. The developed VO50 catalyst shows great potential for industrial-scale aromatic hydrocarbon ammoxidation applications.

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The development of efficient photocatalysts for nitrogen fixation is often hindered by limited visible-light absorption. In this work, a series of UiO-66 materials (UiO-66, UiO-66-Br, UiO-66-NH₂, and UiO-66-NO₂) with different functional groups were synthesized through solvothermal reaction, which showed diverse light harvesting ability. Among them, UiO-66-NH₂ exhibits the superior photocatalytic performance, achieving an ammonia production rate of 11.59 μmol g⁻¹ h⁻¹, which is 2.38 times higher than that of the pristine UiO-66. Comprehensive characterization reveals that the electron-donating –NH₂ group extends the light absorption into the visible region and significantly enhances the separation and migration of photogenerated charge carriers. This study highlights the efficacy of ligand functionalization in tailoring metal–organic frameworks for efficient solar-driven nitrogen fixation.

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The introduction of –NH₂ group significantly enhanced the photocatalytic nitrogen fixation (transforming N₂ into NH₄⁺) activity of UiO-66.

A novel composite material, consisting of carbon quantum dots and magnesium oxide, has been successfully synthesized to effectively stabilization of copper nanoparticles. The characterization of the Cu@CQD@MgO nanocomposite was conducted through a variety of analytical techniques, including FT-IR, SEM, EDS-SEM, TEM, EDX, and ICP analyses. This innovative material has demonstrated remarkable catalytic performance in the synthesis of pyran derivatives, achieving yields between 82 and 97% within 5–20 min, as well as in the production of 1,2,3-triazole derivatives, with yields ranging from 85 to 97% over 15–20 min. The method offers numerous benefits, such as conducting reactions under mild conditions, achieving high yields, and utilizing environmentally friendly solvents like a 1:1 mixture of water and ethanol at room temperature. Collectively, these advantages enhance the efficiency, reliability, and practicality of the synthetic approach outlined in the study, highlighting the potential of Cu@CQD@MgO as a versatile and effective catalyst for organic transformations. Furthermore, the capability to reuse the Cu@CQD@MgO nano catalyst for six consecutive cycles underscores its sustainability and cost-effectiveness, positioning it as a promising choice for large-scale production or continuous processing.

The drug discovery process involves the development of strategies to provide privileged small molecules and allowing access to new potential therapeutic entities. In this work, an efficient process to access chromeno-pyrazolo[1,2-b]phthalazines and indazolo[1,2-b]phthalazines via the three-component reaction between 2,3-dihydrophthalazine-1,4-dione, aromatic aldehydes and 4-hydroxycoumarine/dimedone is described. The notable features of this method include a much milder procedure, a shorter reaction time, a wide range of functional group tolerance, and absence of any tedious workup or purification. This procedure avoids hazardous reagents/solvents and is thus an eco-friendly alternative to the existing methods. Synthesized compounds also evaluated for in silico based pharmacophore investigation to check plausible therapeutic potential. Importantly, the synthesized molecules were found to bind at the active site catalytic cleft of c-Jun N-terminal kinase (JNK3), a well-established anti-neurodegenerative drug target and also plays crucial role in cancer, obesity and diabetic conditions. Higher free energy of binding (− 11.70– − 8.20 kcal/mol)) of the synthesized molecules with JNK3 than previously known JNK3 inhibitor J6F (− 6.5 kcal/mol) suggest sturdy ligand binding. Moreover, binding stability is corroborated by all atomistic molecular dynamics simulation performed in physiologically simulated conditions as well as deep learning-based binding affinity (pK_d) predictions. The therapeutic potentials of the synthesized molecules have been postulated through the detailed structure function analysis and its interaction with their cognate physiological target. DFT investigations also studied for all the synthesized chromeno-pyrazolo[1,2-b]phthalazines and indazolo[1,2-b]phthalazines.

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The epoxidation of olefins is a pivotal reaction in organic synthesis, yielding epoxides that serve as essential intermediates in the production of pharmaceuticals, polymers, and fine chemicals. Conventional epoxidation methods often employ hazardous oxidants and nonrecyclable catalysts, leading to significant environmental and economic drawbacks. This study presents a novel, eco-friendly approach for the aerobic epoxidation of olefins utilizing recyclable NiFe₂O₄@SO₃H@AC magnetic nanoparticles. The catalyst comprises nickel ferrite (NiFe₂O₄) for magnetic separability, sulfonic acid groups (SO₃H) to provide acidic catalytic sites, and activated carbon (AC) to enhance surface area and adsorption properties. Employing molecular oxygen as the terminal oxidant, this system offers a sustainable alternative to traditional methods. The NiFe₂O₄@SO₃H@AC catalyst demonstrates high activity and selectivity across a range of olefins, with excellent recyclability, maintaining performance over multiple reaction cycles. Characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR), confirm the structural integrity and functionality of the catalyst. This work advances the field of green catalysis by providing an efficient, recyclable, and environmentally benign method for olefin epoxidation, addressing critical challenges in sustainability and industrial applicability, and instilling confidence in its reliability.

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In this study, a friendly synthesis route for Mg–Al mixed metal oxide catalysts was successfully developed using the one-pot ball milling method, which was then applied to cyclohexanone self-condensation. This solvent-free solid-phase preparation, driven by mechanical force, rapidly fabricates the mixed metal oxide crystalline phase. Unlike the traditional hydrothermal co-precipitation method, it eliminates the need for solvent separation and recycling, reducing preparation time from hours to just 30 min. Consequently, it is both environmentally friendly and efficient. The structure and performance of the catalyst were analyzed using various techniques. Results indicate that it has a higher active sites density and is effective in cyclohexanone condensation reactions. The mean temperature method (MTM) was also proposed to analyze the temperature fluctuations during the ball milling process, which more accurately reveals the impact of temperature variations on the reaction. The results demonstrate that the ball milling method has a low apparent activation energy (Ea, app = 46.25 kJ/mol), indicating its superiority in catalytic reactions.

The present work describes the simple, general and efficient one-pot synthesis of chromeno [4, 3-b] chromene (4a–4t) and tetrahydrodipyrazolopyridine (8a–8q) derivatives catalyzed by a deep eutectic solvent named ETPP-Br/THF-TCA-DES (ethyl triphenylphosphonium bromide and tetrahydrofuran-2, 3, 4, 5-tetracarboxylic acid). Here, a diverse set of above derivatives were produced with high yields in short times by converging a set of green chemistry metrics in the implementation of multicomponent reactions including the use of low amounts of catalyst (10–15 mg), the absence of the need for harsh temperature conditions, using water as a benign medium and ideal values of environmental factor (E-factor), process mass intensity (PMI) and atom economy (AE). These advantages, along with the introduction and characterization of novel derivatives to the literature, the easy recyclability of DES and its repeated use with a slight decrease in catalytic activity (six times), emphasize the novel aspects of our method as a significant contribution to the advancement of green methods.

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