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Due to the significant pharmacophoric role of 1,4‐naphthoquinone moiety, which is found in numerous biologically active natural products and well‐known chemotherapeutic drugs, including doxorubicin, shikonin, and alkannin, a newly prepared ligand ((E)‐1‐((2‐mercaptophenyl)imino)naphthalen‐2(1H)‐one) can be obtained from the condensation of 2‐aminothiophenol with diketone (1,2‐naphthoquinone) to form Schiff base (HL), which has been characterized using elemental analyses, FT‐IR, 1H‐NMR, and mass spectra. The inner ((La(III), Er(III), and Yb(III)) and outer ((Fe(III), Co(II), and Zn(II)) transitionmetal complexes have been prepared in 1:2 ratio and identified by several spectroscopic instruments. Different characterization tools have been used as elemental analyses, 1H‐NMR, molar conductivity, 13C‐NMR, FT‐IR, thermal decomposition (TG and DTG), UV‐vis, X‐ray diffraction, mass spectrometry, solid reflectance, and magnetic moment. All of them are conjugated to confirm the proposed structures of the metal complexes and are complementary. Also, molecular docking studies for the ligand and its Zn(II) and Yb(III) complexes (using MOE program) have been performed to support the experimental biological activity. Molecular docking studies recommended that (Yb(HL)2)Cl3·6H2O complex is more potent against Aspergillus niger fungus when docked with 1Y43 (aspergilloglutamic peptidase enzyme from A. niger) receptor, while Zn(II) complex recorded the strongest binding energy among the docked compounds against 2W3Z(the crystal structure of a Streptococcus mutans CE4 esterase) and 7AB4 (the crystal structure of the Escherichia coli toxin‐antitoxin system HipBST [HipT S59A]) proteins receptors, respectively. Experimental applications of the free ligand and its metal chelates as antimicrobial and antioxidant activities have been carried out. The former occurred against two fungal species (Aspergillus niger [ATCC:16404] and Candida albicans [ATCC:10231]), two G‐positive bacterial species (S. mutans [ATCC:25175] and Staphylococcus aureus [ATCC:13565]) and two G‐negative bacterial species (Klebsiella pneumonia [ATCC:10031] and E. coli [ATCC:10536]). The DPPH scavenging method has been used to measure the antioxidant activity of the tested compounds. [ABSTRACT FROM AUTHOR]

In this study, metal oxides nanoparticles heterogeneous photocatalysts prepared by coprecipitation and ultrasonic techniques were used for diesel desulfurization. They were characterized by scanning electron microscope, powder X-ray diffraction, energy dispersive analysis, diffused reflectance spectra, photoluminescence analysis and BET surface area. The surface area of catalyst B is larger than catalyst A confirming its higher reactivity. X-ray reflectance spectroscopy was used to analyze the sulfur contents in feed. Thiophene was used as a model fuel to evaluate the photocatalytic activity of catalysts A and B. Using the Scherrer equation, sharp and intense signals suggesting their higher degrees of crystallinity, with average crystal sizes for ZnO, Bi2O3, catalysts A and B, respectively; of 18, 14.3, 29.7, and 23.8 nm. The operational parameters of the desulfurization process were optimized and have been studied and the maximum sulfur removal was achieved via a further solvent extraction step. A diesel fuel with a 24 and 19 ppm sulfur content and hence a total sulfur removal of 94.6% and 95.7% was acquired for catalysts A and B, respectively (sulfur compounds concentration in diesel fuel feedstock was 450 ppm). These findings demonstrated that photocatalysts A and B are good and effective catalysts for desulfurization of diesel fuel. [ABSTRACT FROM AUTHOR]