Structural, computational and antimicrobial studies of 2–[(E)–[2–(2,4,6-trimethylbenzenesulfonyl)-hydrazinylidene] methyl] benzoic acid and its Cu(II), Zn(II) and Co(II) complexes

Abstract

The Schiff base 2-[(E)-[2-(2,4,6-trimethylbenzenesulfonyl)hydrazinylidene] methyl] benzoic acid (TBSHOPA) was synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and UV-vis measurements. X-ray crystal data showed that the compound crystallized as the imine form, in the monoclinic crystal system and P21/c space group. Co(II), Zn(II) and Cu(II) complexes of the type ML2(H2O)2,[L= TBSHOPA], were synthesized. Microanalytical and spectroscopic data indicated that the Schiff base coordinated as a monoanionic bidentate ligand via the imino nitrogen and the carboxylic oxygen to form six-coordinate octahedral metal complexes. Theoretical calculations were conducted by the DFT method using the B3LYP functional and 6-31+G(d,p)/LANL2DZ basis set. Noncovalent interaction (NCI) analysis on TBSHOPA with the aid of a locally developed program, ‘’Bonder’’, indicated the presence of a number of non-covalent interactions in the solid-state. Molecular docking studies were performed to predict the binding potential of the compounds on Staphylococcus aureus (SA), Escherichia coli (EC), Bacillus subtilis (BS), Salmonella typhi (ST) and Candida albicans (CA) using AutoDock tools. The compounds were screened for in vitro antimicrobial activity against SA, EC, BS, ST, and CA. The results showed that the Co(II) and Zn(II) metal complexes exhibited better antimicrobial activities compared to other compounds.