Research on Chemical Intermediates最新文献

Developing efficient and environmentally sustainable pathways is a fascinating focus within the field of green chemistry. In this study, a bimetallic Co-Mg metal–organic framework (Co-Mg MOF) was synthesized through solvothermal conditions using Co²⁺ and Mg²⁺ ions along with NH₂BDC (2-amino terephthalic acid) as a rigid ligand. Comprehensive characterization was performed using powder X-ray diffraction (PXRD), nitrogen adsorption–desorption isotherm (BET method), thermogravimetric analysis (TGA), elemental mapping, and inductively coupled plasma (ICP) techniques. The as-synthesized catalyst exhibited great catalytic performance in the Knoevenagel condensation of malononitrile and benzaldehyde, possibly due to its abundance of basic and acidic sites. Besides this, the bimetallic MOF catalyst demonstrated superior catalytic activity compared to its single-metal counterparts (Co-MOF and Mg MOF), this enhanced performance is likely due to the synergic effect of incorporating Mg²⁺ into the Co-MOF framework. With the optimization of reaction conditions, a significant yield of the final products (involving various aldehydes and malononitrile) was achieved at room temperature within a short duration. The as-synthesized catalyst represented good stability and recyclability through the reaction process even after the 4th run. The results showed that the as-synthesized bimetal Co-Mg MOF exhibited superior potential as a catalyst in the Knoevenagel condensation reaction, in the presence of green solvent (ethanol).

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Effective and notable elimination of leaching of the metal nanoparticle from the catalyst during catalytic processes is still a big challenge for researchers in the design of heterogeneous catalysts. Metal–organic frameworks in both pristine and modified types with an excellent capacity for adsorption and stabilization of metallic active species have received special attention. In this study, Zn-MOF (TMU-16-NH₂) was selected and modified with urea to enhance amino groups on the surface, and the Zn-MOF-NH₂ was further reacted with glutaraldehyde to achieve support with various sites containing nitrogen and oxygen atoms named Zn-MOF-NH₂-glutaraldehyde. This adsorbent revealed an outstanding capacity in the adsorption and stabilization of palladium nanoparticles to fabricate a novel heterogeneous catalyst Zn-MOF-NH₂-glutaraldehyde@Pd for the Suzuki coupling reaction. High performance, great yield of products, reusability, easy work-up, clean profile of reaction, and short reaction times are some of the benefits of the Zn-MOF-NH₂-glutaraldehyde@Pd catalyst.

This study presented the synthesis of cerium dioxide (CeO₂) nanoparticles utilizing carboxymethyl chitosan (CMC) to augment their biocompatibility with subsequent silver doping to refine their properties. The undoped CeO₂ nanoparticles were characterized as a cubic fluorite crystal structure with an average particle size of approximately 17.5 nm. The undoped CeO₂ nanoparticles preserved the cubic fluorite crystal structure and spherical morphology of the nanoparticles; however, it induced modifications in their physical properties, including a reduction in particle size and unit cell volume and an expansion of lattice spacing. Cytotoxicity assays revealed that undoped CeO₂ nanoparticles did not exhibit cytotoxic effects on HaCaT cells within the defined concentration range, indicating that CeO₂ nanoparticles synthesized with CMC significantly enhanced their biocompatibility. The silver-doped CeO₂ nanoparticles demonstrated enhanced antioxidant activity and an elevated sun protection factor (SPF) compared to their undoped counterparts. The enhancement of these properties highlights their potential applications in biomedicine and cosmetics.

Magnetic catalysts are known for their exceptional reusability and recyclability, which not only makes the process more cost-effective but also aligns with green chemistry principles. The use of magnetic catalysts in the synthesis of 2,4,5-triaryl imidazoles presents a sustainable, efficient, and versatile approach that aligns with the evolving demands of modern chemical synthesis. In this paper, we fabricated Fe₃O₄@SiO₂-ABMA-MnCl₂ nanocomposite as a novel and recoverable nanocatalyst for the synthesis of 2,4,5-triaryl imidazoles through the three-component reaction of various derivatives of aromatic and heteroaromatic aldehydes with benzil derivatives and ammonium acetate in ethylene glycol. Under this catalytic system, a broad spectrum of triaryl imidazole derivatives was afforded with high to excellent yields in less than 1 h. Several spectroscopic techniques well identified the structure of Fe₃O₄@SiO₂-ABMA-MnCl₂ nanocomposite. Conducting reactions in ethylene glycol as a solvent, synthesis of products with excellent efficiency in less than one hour, very good identification of the catalyst structure, simple separation of the catalyst from the reaction mixture, and its high reusability are some of the valuable features of this catalytic system. VSM, TGA, ICP-OES analyzes showed that the Fe₃O₄@SiO₂-ABMA-MnCl₂ catalyst has high stability and has maintained its magnetic nature and structure after recovery (despite 8 consecutive uses).

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In synthetic chemistry, cycloaddition is a valuable tool for creating heterocyclic rings, with numerous applications in a variety of fields. The objective of this research is to develop a NiCu/ZIF-8 catalyst to facilitate a three-component reaction known as the "click reaction," which is used to synthesize 1,2,3-triazoles. The catalyst was designed to catalyze 1,3-dipolar cycloaddition reactions involving several azides and alkynes. The metals nickel and copper were immobilized on the surface of ZIF-8 to maximize the catalyst's performance. The catalyst was characterized using various analytical methods, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). Remarkably, the catalyst demonstrated stability, maintaining its catalytic properties and efficiency after five recycling cycles. The advantages of this procedure are manifold, including high speed, mild conditions, reusability, high yield (75–95%), and affordability, which make it an attractive method for 1,3-dipolar cycloaddition reactions.

A highly organized and green protocol has been developed for fabricating amino methylene bisphosphonates using sulfated choline ionic liquid (SCIL) catalyzed under ultrasonication. This method involves various substituted amines, triethyl orthoformate, and diethyl phosphite. All synthesized derivatives were characterized by Nuclear Magnetic Resonance NMR (¹H and ¹³C), confirming product formation. This approach significantly enhances the synthesis of desired products with high yields. The choline is biodegradable and it was widely used to prepare deep eutectic solvents and to synthesis of ionic liquid to replace the Cl⁻ ion to hydroxide ion it gives good basicity, and modification of terminal hydrogen is replaced by ClSO₃H it gives good acidity; hence the choline-based catalyst can use in both acid and base promoted reaction. The synthesized SCIL was characterized using by Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Scanning electron microscope (SEM) demonstrating the functionalization of the sulfonate group to form an effective acidic ionic liquid.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 2 Given name: [Reddi Mohan Naidu] Last name [Kalla], Author 3 Given name: [Araveeti Eswar] Last name [Reddy] and Author 4 Given name: [Tahani Mazyad] Last name [Almutairi]. Also, kindly confirm the details in the metadata are correct.Yes the author detials were correct

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A green and efficient synthesis of novel cyclohexanone diesters was achieved via the double addition of dimethylmalonate to dibenzylideneacetone derivatives in the presence of imidazolium-based ionic liquids as catalysts, without the use of any base. Ionic liquids were synthesized by anion exchange with various organic acid salts. The reaction was optimized by evaluating the effects of various ionic liquids. Among the tested ionic liquids, 1,3-dibutyl-2-methylimidazolium hydroxide ([Dbmim][OH]) demonstrated the highest catalytic performance, yielding up to 99% of the desired products in ethanol as the solvent. The study highlighted the remarkable dual benefits of ionic liquids, showcasing their outstanding catalytic efficiency along with significant environmental advantages, positioning them as a sustainable, eco-friendly, and reusable alternative for the base-free synthesis of cyclohexanone diesters.

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In this study, we report the development of the most economical synthesis route for magnetically separable graphitic carbon nitride with iron oxide (g–C₃N₄–Fe₂O₃) photocatalyst using an iron-rich natural laterite soil sample as a readily available and cost-effective iron precursor. A simple chemical acid extraction method used to synthesize Fe₂O₃ from a laterite soil sample as an iron precursor naturally found in Ratnagiri, Maharashtra, India. Additionally, to enhance the photocatalytic activity of the pure Fe₂O₃, we have incorporated it with the g–C₃N₄, and the resultant material shows superior performance. The structural and optical properties of the resulting Fe₂O₃, g–C₃N₄, and g–C₃N₄–Fe₂O₃ nanocomposite were thoroughly characterized using physio-chemical methods. The characterization results successfully established heterojunction between g–C₃N₄ and Fe₂O₃, improving the photogenerated electron–hole pair lifetime. The g–C₃N₄–Fe₂O₃ nanocomposite demonstrated enhanced photocatalytic activity for the degradation of methyl orange (97.66%) and textile effluent (97.00%) under natural sunlight with excellent photocatalytic stability after five consecutive cycles. These results highlight a new way of large-scale synthesis of iron-based nanocomposite photocatalyst using laterite soil as an inexpensive iron precursor.

This research aimed to prepare quaternized magnetic alumina nanotube by anchoring hexamethylenetetramine onto chlorinated Fe₃O₄@alumina surface. The prepared materials were characterized by XRD, EDX, VSM, FTIR and FESEM techniques. In view of an environmental application of ionomers, the prepared composite was used for uptake of Pb (II) and malachite green (MG) from aqueous solution, and results were compared by the Fe₃O₄@alumina. The optimum value of four main factors on the removal efficiency including adsorbent dosage, pH, contact time and ionic strength was obtained by response surface method (RSM) based on Box–Behnken design (BBD). Kinetic and isotherm studies revealed that pseudo-second-order model and Freundlich model are dominant in adsorption by magnetic alumina besides the Langmuir model better described the removal by magnetic ionomer. Results revealed that modifying the magnetic alumina with a quaternized fragment improved its performances for Pb and MG adsorption as the adsorption capacity of Pb (II) and dye is 312 and 151 mg g⁻¹ by ionomer, respectively.

The present research delineates the synthesis and catalytic assessment of a novel Fe₃O₄@SiO₂–Pr–THAM–(OSO₃H)₃ magnetic nanoparticles. The structural conformation of as-prepared Fe₃O₄@SiO₂–Pr–THAM–(OSO₃H)₃ nanoparticles was evaluated using numerous analytical methods like Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis. The catalytic potential of Fe₃O₄@SiO₂–Pr–THAM–(OSO₃H)₃ was tested for the syntheses of 4H-chromenes through one-pot condensation of 2-hydroxybenzaldehyde, cyclic 1,3-diketones, and 4-hydroxycoumarin in aqueous solution at 50 °C. The current methodology offers the benefits of superior catalytic activity, the utilization of environmentally friendly solvents, easy work-up procedure, excellent yield, magnetic separation, shorter reaction times, and catalyst reusability with no significant loss in potency after six cycles. The synthesized 4H-chromene derivatives were screened for antibacterial and in vitro antioxidant study and were found to have promising activities supported by molecular docking studies.

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