Journal of Saudi Chemical Society最新文献

Carbon nanotubes (CNTs) are highly promising materials for the adsorption of dyes from water. Recently, there has been a growing interest in Prussian blue-type coordination polymers due to their inexpensive nature, chemical stability, and simple synthesis using non-toxic metals that are prevalent in the earth. The results present a straightforward technique for effectively altering the surface of CNT using cobalt-iron-based prussian blue (CoFe-PB). The procedure led to a significant increase in the removal of crystal violet (CV) from water relative to the bare CNTs. The maximum removal efficiency (about 93 %) of CV dye was obtained at pH 6 with fast saturation time (15 min). The use of the coating approach yields a core–shell structure consisting of CNT as the core and a CoFe-PB shell. The CoFe-PB shell, with a thickness of 10–15 nm, forms a highly conformal coating that completely covers the CNT. The high conformance of the coating is considered an essential characteristic for its strong adsorption performance. The method demonstrates the significant potential of prussian blue-type materials, when appropriately coated, as very effective adsorbent materials.

This study reports the production of a heterojunction copper oxide-zinc oxide nano-photocatalyst based on lemon leaf extract, which acted as both a stabilizer and a capping and reducing agent. The fabricated photocatalyst had a smooth surface with numerous functional groups, and its energy band gap was measured to be 3.14 eV, which is suitable for photocatalytic applications. Toxic Congo Red dye was used as a model pollutant to investigate the photocatalytic degradation performance of the proposed CuO-ZnO nano-photocatalyst. The photocatalyst exhibited a rapid degradation rate under sunlight irradiation, reducing the concentration of the dye by almost 70 % within 50 min and exhibited pseudo-first-order kinetics. The performance of the photocatalyst was also evaluated based on its quantum yield and figure of merit, which were found to be 6.63 x 10⁻⁹ molecules photon⁻¹and 3.31 x 10⁻⁴, respectively. In addition, the proposed catalyst displayed good stability for up to 5 cycles. Based on these results, the fabricated CuO-ZnO nano-photocatalyst outperformed previously reported photocatalysts. The mechanisms associated with the dye degradation were also explained by an interfacial charge transfer reaction.

The emergence of COVID-19 had an unprecedented impact on society, leading to the widespread usage and disposal of surgical face masks (FMs). This work contributes to repurposing FMs into carbon materials through simplified solvothermal-assisted pyrolysis processes for supercapacitor applications. XRD and FESEM were employed to investigate the materials' microstructural and micrographic characteristics. The FM 700 has a specific capacitance value of 182.61 Fg⁻¹, more significant than the other produced sample in the 1 M KOH electrolyte. The symmetric solid-state supercapacitor with a maximum capacitance of 92.67 Fg⁻¹ is constructed under perfect circumstances. After 10,000 cycles, FM 700-SSSD maintained 89 % of its value. Turning FMs into carbon materials for energy storage applications is made more accessible by this method and also prevents the environment from pollution.

Traditional molecular recognition studies usually focus on obtaining strong host–guest interactions, which may lead to the neglect of important tendencies caused by other factors. Moreover, most receptors typically fix their recognition sites in the backbone of the receptor, resulting in great synthetic challenges for varying recognition functional groups. In this contribution, we developed a new class of tetrapodal receptors. The terminal functional groups of the receptor can be varied by simple chemistry. Through ¹H NMR titration experiments and binding constant analysis, the influence of the size and shape of alkane chains on monosaccharide recognition was investigated. The introduction of ester functional groups allows the access of moderate binding affinity to unveil otherwise masked contribution of dispersion force in saccharide recognition. These results also imply that stronger forces may not always be beneficial for host–guest binding while functional groups with a particular shape may favor the discrimination of isomers through steric hindrance effect. Thereby, these tetrapodal receptors and their analogues provide an ideal platform for comparing the effects of various functional groups on molecular recognition.

This study introduces MnFe₂O₄@SiO₂-SiO₃H as a novel magnetic catalyst and thoroughly investigates its structure, catalytic activity, and reusability. The synthesis of the magnetic catalyst was meticulously characterized using an array of analytical techniques. Utilizing MnFe₂O₄@SiO₂-SiO₃H, the synthesis of functionalized oxazolidine-2-ones were performed, versatile compounds widely employed in chiral auxiliaries, protecting groups, and medicinal chemistry. Remarkably, the two-step process from chalcones demonstrated one of the shortest reported pathways, highlighting the efficiency of our novel nanocatalyst. To elucidate the stability and reactivity of the synthesized products, we employed Density Functional Theory (DFT) calculations, including molecular electrostatic potential (MEP) mapping and reactivity indices such as electronegativity, electrophilic index, softness, and hardness, as well as frontier molecular orbitals (HOMO-LUMO). Furthermore, our investigations extended to the recycling capabilities of the nanocatalyst. Through a comprehensive evaluation of at least five reaction cycles, MnFe₂O₄@SiO₂-SiO₃H showcased a remarkable retention of activity (97–92 %), reaffirming its reusability and long-term potential. Our research presents MnFe₂O₄@SiO₂-SiO₃H as a highly effective and recoverable nanomagnetic catalyst for organic reactions, with demonstrated applications in synthesizing functionalized oxazolidine-2-ones. As such, our findings offer a promising alternative to traditional methods, presenting new opportunities in catalysis and materials science.

Fluopyram is a highly effective agricultural fungicide targeting succinate dehydrogenase (SDH). Twenty-six novel amide derivatives containing azetidine were designed and synthesized with fluopyram as the lead, and their biological activities were tested. The results showed that some compounds had obvious antifungal activities against Phomopsis sp., among them, the EC₅₀ value of compound C24 was 5.7 mg/L, which was significantly better than fluopyram (105.4 mg/L). The curative and protective activities of compound C24 on kiwi fruit infected with Phomopsis sp. were 42.2 and 52.9 %, which were better than that of fluopyram (30.4 and 35.6 %) at 200 mg/L. Moreover, compound C24 exhibited excellent inhibitory against SDH. The results of scanning electron microscopy (SEM) indicated that the mycelium of Phomopsis sp. collapsed or even ruptured after compound C24 treatment. Meanwhile, molecular docking showed that compound C24 was deeply embedded into the SDH binding pocket, and the binding model was stabilized by a cation–π interaction with Cys-40, Tyr-58 and an H-bond with Lys-455 and Asn-452. Compound C24 can provide a valuable idea to find new succinate dehydrogenase inhibitors.

M-cresol, one of phenolics, is highly toxic, refractory, and threatens human health and ecological safety. The study on the efficient m-cresol degradation technologies is crucial and helpful to restrain its discharge into water body. A composite of MnO-doped red mud (RM) to activate peroxymonosulfate (PMS) for the m-cresol degradation was fabricated and employed, favorable to the recycling and utilization of RM. Considering the catalytic activity and cost, 0.1 M/RM@G exhibited an excellent degradation capacity attributing to strong Fe₃O₄ and MnO synergy and was considered as the best catalyst among the investigative catalysts. 100 % of m-cresol and 71.4 % of COD could be degraded within 90 min under 2 g/L catalyst, 10 mM of PMS, 3-8 of initial pH and 50 mg/L m-cresol in the 0.1 M/RM@G/PMS system. The reaction rate constant (0.045 min⁻¹) of 0.1 M/RM@G was much larger than RM@G (0.012 min⁻¹), ARM (0.0048 min⁻¹) and WRM (0.0028 min⁻¹). Main Mn and Fe active components and abundant mesoporous structures on the catalyst surface could efficiently drove electron transfers, and further accelerated the redox cycles of Mn(III)Mn(II) and Fe(III)Fe(II) for activating PMS. ¹O₂ played a crucial role in degrading m-cresol. Based on the experiment data, the generation mechanism of radicals and the possible pathways of m-cresol degradation were proposed in the 0.1 M/RM@G/PMS system. This finding provides a new way for the synthesis of the efficient catalyst with RM and optimal operating strategies for the treatment of m-cresol wastewater.

N-Arylpyrazoles are important building blocks in many biologically active compounds, natural products, pharmaceuticals, and industries. It is an important moiety of various drugs and exhibits extensive biological activities viz., antibiotic, anticancer, antifungal, anti-inflammatory, anti-coagulant, analgesic, antipyretic, anti-depressant, insecticidal, and hyperglycemic activities. Various protocols have been designed for the synthesis of N-arylpyrazoles facilitated by a wide variety of metal-based catalysts at high or room temperature, metal free reactions, various named reactions, multicomponent reactions, and those occurring under different electromagnetic radiations. Various ligands are found to promote Cu-catalyzed N-arylation of pyrazole under mild conditions in short time. This review describes the synthesis and biological applications of N-arylpyrazole derivatives reported during 2019–2023.

This study utilized incipient wetness impregnation to synthesize bentonite materials and to enhance their physical characteristics with ruthenium (Ru) and strontium (Sr) ions. The atomic composition of the materials was confirm confirmed via the analysis of the EDX measurements. X-ray crystallography indicates that the materials have almost similar diffraction peak profiles, and that the addition of Sr increases the crystallinity of the bentonite grains. Dielectric and electrical properties, measured between 25 °C and 55 °C at frequencies of 1 kHz −1 MHz, revealed that the real and imaginary impedances increased upon the introduction of 5 % Ru and 5 % Sr, possibly due to Ru and Sr segregation into the grain boundaries, increasing the resistance of the bentonite granular structure. For all materials, the observed saturation of the real electric modulus at high frequencies, and the reduction of the permittivity with increasing frequency, may be explained by the Maxwell-Wagner interfacial polarization and Koop's empirical theory. This trend is more pronounced for the bentonite with Sr, highlighting the essence of the present work for engineering interfacial polarisation applications associated with supercapacitors and batteries.

The designed and synthesized multifunctional properties of bis-hydrazono[1,3,4]thiadiazoles became important for developing an efficient medication for Alzheimer’s disease. Thiadiazoles were characterized and studied towards this target as an acetylcholinesterase inhibitor (ChEIs). In this study, one-pot synthetic strategy was applied for the synthesis of bis-hydrazono[1,3,4]thiadiazole series from 2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbodithioic acid) and hydrazonoyl chlorides. The greener pastures, in silico, an environmentally-friendly and free computer-aided method, bioactivity studies of the bis-hydrazono[1,3,4]thiadiazoles 4a-h exhibited various possible interesting inhibitory activities against AChE showing similar behaviour to the approved drugs, Donepezil, Galantamine and Rivastigmine. For a fair comparison, the superpositions of 4a-h, and Donepezil, Galantamine and Rivastigmine docked together into the functional domain (binding pocket) of 1EVE to reveal interesting different molecular laydowns of the compounds. On the other side, the display of the molecules before and after docking was discussed. The binding affinity slightly differs between Donepezil, Galantamine, Rivastigmine, and the ligands 4a-h. The range of the recorded binding affinity for 4a-h is from (−9.4 to −8.4 kcal/mol⁻¹)^, whereas the binding affinity for Donepezil, Galantamine and Rivastigmine is (−11.1, −9.8 and −8.0 kcal/mol⁻¹ respectively), which is higher than all the prepared ligands.

Furthermore, the binding amino acids also varied among the studied compounds in this study. Phe290, Phe330, Phe331, Trp279, Tyr70, Tyr121 and Tyr334 are the common amino acids binding with the FDA-approved AChE inhibitors for treating AD, Donepezil, Galantamine and Rivastigmine and ligands. Notably, the number of hydrophobic and hydrogen interactions studied between the ligands 4a-h and the Donepezil, Galantamine and Rivastigmine drugs were compared as a preliminary indicator towards a successful inhibitor. The comparative study in this research work aims to rank our compounds with respect to the approved medications. This is a friendly environmental preliminary helpful indication before leaping into time and energy-consuming experimental work. Organ toxicological endpoints and toxicity-predicted activity were obtained using the ProTox-II web server for both the approved medication and ligands. Later, in-vitro acetylcholinesterase inhibition assays were conducted to assess the efficacy of bis-hydrazono[1,3,4]thiadiazoles 4a-h as inhibitors of acetylcholinesterase (AChE) in comparison to Donepezil. Results indicated promising inhibition activities for example 4 h, 4 g and 4d to the testing drug Donepezil for breaking down the neurotransmitter acetylcholine.