Journal of Saudi Chemical Society最新文献

A new composite material, ZnO/Yb₂Zn-TiO₆@g-C₃N₄ has been synthesized by simple hydrothermal process. This composite has been characterized using various material characterization techniques and was found to have a heterojunction amongst Yb₂Zn-TiO₆ and g-C₃N₄, leading to higher light absorption and poorer charge carrier recombination rates. Furthermore, the evaluation of the charge carrier density revealed that the incorporation of small sized ZnO (40 nm) into Yb₂Zn-TiO₆@g-C₃N₄ led to heightened disintegration of the photoinduced charge carriers. This observation implies that the presence of said metal oxide enhances the photocatalytic performance by greatly promoting the effective separation of charge carriers for various applications. When tested with bromothymol blue, the 20 wt% ZnO/Yb₂Zn-TiO₆@g-C₃N₄ composite showed a photodegradation rate several times greater (98 %) than individual ZnO, C₃N₄ and Yb₂Zn-TiO₆, respectively. The degradation efficiency of the ZnO/Yb₂Zn-TiO₆@g-C₃N₄ nanostructure in the absence of light was 24 %. The increased photoactivity of the composite material is due to the efficient separation of charge carriers and also due to the high redox capabilities resulting from the heterojunction. The composite also demonstrated stable photocatalytic performance over five cyclic runs and was effective in treating real printed ink wastewater. Furthermore, ZnO/Yb₂Zn-TiO₆@g-C₃N₄ was found to have excellent antibacterial properties in opposition to Escherichia coli, (Inhibition = 16(±0.2) mm) as well as Bacillus subtilis (Inhibition = 22(±0.3) mm). The MIC of the said nanomaterials against Escherichia coli as well as Bacillus subtilis were 50 µg/mL and 30 µg/mL respectively. The detailed explanation of the photodegradation mechanism was also provided. The use of this composite material can help to reduce the harmful effects of contaminants and microbes in aquatic environments and promote environmental sustainability.

In this research, zeolite ZSM-12 with Si/Al ratio = 80 was synthesized by hydrothermal method. The synthesized zeolite ZSM-12 was modified using Fe and Ga metals and a combination of these two metals, 1 % iron metals (Z80-Fe) and 1 % gallium metals(Z80-Ga), and a 2 % combination of these two metals (Z80-Fe-Ga). The physicochemical properties of synthesized zeolites were evaluated and compared by XRD, EDX-dot-mapping, NH3-TPD, BET, FT-IR, and TGA analyses. The catalytic assessment of synthesized zeolites in the HTO (n-hexane to olefins) process in a fixed bed reactor under atmospheric pressure and Weight hourly space velocity (WHSV) equal to 4 h⁻¹ at 550 °C was evaluated. Various parameters such as selectivity towards light olefins, propylene to ethylene (P/E ratio), production of light alkanes, and aromatic compounds (BTX) were investigated. The results show that using metals led to the improvement and adjustment of the acid sites of zeolite, and the highest amount of light olefin and the lowest amount of coke were obtained. The result of the n-hexane to olefin process showed that the yield of light olefins was significantly improved in all modified catalysts compared to parent zeolite MTW. Compared to other modified zeolites, Z80-Fe-Ga zeolite has the highest yield of light olefins, equal to 59 %. This zeolite performs better due to the presence of gallium and iron metals and shows the highest propylene selectivity (P/E = 2.4). In addition, according to the results of the TGA analysis, the content of coke on the Z80-Fe-Ga catalyst after the catalytic reaction is much less than that of other catalysts after the catalytic reactor test.

Facilitating energy resource deficiency and environmental contamination, this work focuses on sustainable biodiesel production through the esterification reactions of oleic acid (OA) with methanol. To address the reaction, a novel heterogeneous acid catalyst, 12-tungstophosphoric acid (TPA) immobilized on Sn-based MOFs (Sn(II)-BDC) was synthesized via a simple, green solvent, and easy-to-implement synthesis strategy for the first time, and applied effectively for esterification process of OA to produce biodiesel. The structure and composition of as-obtained catalyst have been verified using XRD, FTIR, N₂ physisorption, SEM, EDX, TG, Py-FTIR, TPD-NH₃, and XPS techniques. The obtained TPA/Sn(II)-BDC catalyst was found to be the best with 60 wt% of TPA loading, which resulted in an OA conversion of 91.7 % at optimized conditions of 0.15 g catalyst loading and methanol to OA molar ratio of 20:1 at temperature of 120 °C in 4 h, and the excellent performance arises from available pores structure, large amounts of acidic sites, good stability and the synergistic catalytic effect of TPA and Sn(II)-BDC. Furthermore, the composite catalyst reusability has been studied for five cycles, and it exhibits an acceptable conversion. This research provides a green and large-scale synthesis route for the sustainable production of biofuels by constructing heteropolyacids/Sn-based MOFs synergistic catalysts.

The conversion of organic waste into valuable commodities is essential for safeguarding the environment and promoting the sustainable development of the economy. This investigation centres on the production of Zinc ferrite nanoparticles (ZnF NPs), modified eggshells (MES) impregnated with chitosan (CS) and coated with poly ortho-toluidine P(OT) nanocomposites (NCs). This synthesis involves a quaternary composition denoted as P(OT)/MES/CS/ZnF NCs, achieved through chemical polymerization techniques. The resulting NCs were characterized and applied for the removal of Brilliant Green (B.GR) and Acid Red (A.RE). Four distinct compositions, namely pure P(OT), binary P(OT)/MES, ternary P(OT)/MES/CS, and quaternary P(OT)/MES/CS/ZnF NCs, were synthesized. The outcomes revealed that the quaternary P(OT)/MES/CS/ZnF NCs exhibited the highest adsorption capacities for B.GR and A.RE at)27.03 and 142.8 mg⁻¹(, respectively. The findings revealed that the most favorable parameters for the removal of A.RE were attained at a pH of 2, using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 25 mg/L for a duration of 120 min. On the other hand, when it comes to removing B.GR, the best results were shown while using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 5 mg/L for 120 min, specifically at a pH of 6. The greatest real wastewater removal efficiencies for A.RE dye and B.GR dye, respectively, were found to be 99.5% and 97.6% under these operating circumstances. These optimal quaternary NCs demonstrated the ability to be regenerated four times without significantly compromising their adsorption properties and exhibited a remarkable capacity to remove 96–98% of dyes from real polluted water. Through the use of regression data and a pseudo-second-order model, the adsorption kinetics were explained, with R² values of 0.994 for A.RE and 0.993 for B.GR, respectively. Thermodynamic parameters of dye adsorption by the NCs affirmed the fact that adsorption occurs spontaneous and have endothermic nature. This study underscores an effective synthesis approach applicable for large-scale production of new adsorbents for water treatment purposes.

Eugenol, a primary component of clove oil, is a compound of considerable interest in medicinal chemistry due to its demonstrated potential as an effective agent in various therapeutic applications. In this study, a series of eugenol derivatives were designed and synthesized based on the hybridization of eugenol with 1,2,3-triazole and chalcone moieties. Compound 5j and 5k were denoted as lead structures against Mycobacterium tuberculosis Shikimate Kinase (MtSK). Moreover, the docking studies indicated that both the eugenol and triazole fragments in compound 5j and 5k played a pivotal role in the inhibition activity of MtSK, owing to their binding interactions with Arg58, Pro118, and Arg136 residues. Furthermore, in silico drug-likeness prediction analysis suggested that the majority of the synthesized compounds exhibit good oral bioavailability based on their molecular properties and Lipinski’s Rule of Five predictions.

The core/shell nanocomposite has attracted considerable attention and developed at the frontier of advanced materials due to their unique properties and versatile applications, especially the core@shell Au nanoparticles (NPs). As noble metal, Au NPs is employed to construct core@shell architecture of nanocomposite as core or shell. In the paper, a comprehensive overview of the approach and technique for fabrication of Au coating core NPs as core@Au is provided. Seed-mediated growth technique as the traditional method is elucidated firstly, followed by templated and assembly synthesis method. Some other synthetic strategy based on chemical substance, such as sodium citrate, silane coupling, polymer, thiols, micelle method, and electrodeposition, transmetalation method are highlighted in detail. The representative procedures and mechanism of the approaches for construction of core@Au nanocomposite are discussed. Besides, three main categories of core@Au nanocomposite, including simple substance@Au, oxide@Au, metal salt@Au NPs are introduced briefly. In addition, the synthesis and modification of Au NPs associated it’s properties and applications are briefly proposed. As a whole, the universal approaches for synthesis of nanoparticles and core@shell NPs are described simply. It is tend to exhaustively cover all the field of Au NPs. The challenges and perspectives in the future for core@shell NPs is proposed. The review provides shortcut for researchers quickly obtaining technique and experience for core@Au nanocomposite.

2H-azirines have represented versatile building motifs in the domain of organic chemistry owing to their excellent reaction activity induced by the high strain of the three-membered ring species. Over the past decades, brilliant achievements have been made in 2H-azirine chemistry involving the construction as well as the transformation of such functional compounds. In the presence of transition metals, strong bases or oxidants, 2H-azirines could be converted into the corresponding products under harsh reaction conditions. Different from traditional catalytic methods, the utilization of photochemistry has proved to be an extremely fascinating protocol that facilitates the construction of 2H-azirine blocks from diverse substrates and further conversion into various derivatives with interesting biological activities. In this regard, more and more light-driven synthetic approaches featuring high efficiency and mild conditions have been developed. Herein, we summarized the accessibility and applications of 2H-azirines as powerful precursors or key intermediates for the synthesis of biologically promising molecules in the presence of photocatalytic conditions.

In this manuscript, we are motivated to investigate the reaction site-selectivity for the hydrazo thiazole derivatives (6a–c) with different types of active methylene groups such as malononitrile, and ethyl cyanoacetate. Based on their structural investigations and spectrum data, the results of these reactions have been established to be iminopyridazines (7a–c) and 6-oxopyridazine derivatives (8a–c). We tested the ability of the newly synthesized pyridazine derivatives to inhibit the microbes and COVID-19 proteins. Human coronavirus 229E (HCoV-229E) was used to investigate the antiviral efficacy of prepared compounds. Green monkey kidney (Vero-E6) cell lines were used to investigate MTT and cytopathic effect (CPE). The new 6-oxopyridazine derivatives (8a–c) revealed significant inhibitory efficacy and were capable of inhibiting the human coronavirus 229E. Moreover, the antimicrobial result showed that compounds iminopyridazine (7c) followed by iminopyridazine (7a) followed by iminopyridazine (7b) exhibited excellent antimicrobial properties toward all utilized strains, usually greater than that of common reference drugs, with MIC values ranging from 13 to 21 ppm, from 9 to 14 ppm, and from 8 to 19 ppm whereas, the remaining substances appeared to be promising effective. Structure-activity relationship (SAR) revealed that pyridazine scaffolds containing NH group, as well as substituted electron withdrawal group (Cl) in para-position for benzene ring attributed to thiazole moiety have the best activity. The current study successfully illustrated the possible application of heterocyclic derivatives with pyridazie nucleus including thiazole ring as the main compound in the development of dual antiviral (COVID-19) and antibacterial pharmaceuticals in the future.

Ionic liquids are being used to increase the stability and efficiency of perovskite solar cells (PSCs). Ionic liquids not only help to enlarge grain size of perovskite due to their high thermal stability and low volatility, but also passivate defects on the perovskite surface, increasing the stability and efficiency. 1-ethyl-3-methylimidazolium tetracyanoborate ionic liquid is one of the excellent ionic liquids, which greatly increased the growth of perovskite crystal particles and enhanced the stability of PSCs. From calculation by Gaussian 09 program, electron density of N in the B(CN)₄⁻ ion is about 6.3. So, B(CN)₄⁻ can form chelate bonds or hydrogen bonds with Pb²⁺ or I⁻. The power conversion efficiency (PCE) of the three-layer structured PSCs fabricated using this ionic liquid was 13.8 % for the maximum, and it was maintained above 80 % of the initial efficiency under full-spectrum sunlight at 60–65 °C in air with relative humidity ranging from 40 to 50 % after 240 h.

Context

Solubility prediction based on the general solubility equation (GSE) rests on reliable values for the isobaric heat capacity difference ΔC_p,1 of the solid solute. Usually, this value is estimated with either zero or the melting entropy ΔS₁(T_m,1) or, in few cases, is extrapolated from data of thermally stable melts of the solute. This causes uncertainties in the prediction.

Objective

To improve prediction accuracy a simple regression method is proposed that determines ΔC_p,1 from measured solubilities.

Materials and methods

Published experimental solubilities in neat organic solvents at 298 K of a model compound (L-(+)-ascorbic acid (LAA)) have been regressed using the GSE together with the Hansen parameter model for the activity coefficient.

Results and discussion

Regression yielded ΔC_p,1 = 238 J∙mol⁻¹∙K⁻¹ which agrees well with cross-validation results and is consistent with estimates from various group contribution methods. It was found that prediction accuracy improved in the order of increasing ΔC_p,1, that is, from 0, via 91 (=ΔS₁(T_m,1)) to 238 J∙mol⁻¹∙K⁻¹. It could be shown that mole fraction solubility of LAA can be forecast this way with an accuracy within current inter-laboratory variation.

Conclusion

The proposed method shows a general way to improve prediction accuracy of activity coefficient based solubility models by determining ΔC_p,1 without resorting to common assumptions. The method is universally applicable and easy to implement.