Synthesis, Characterization, DFT and Antibacterial Screening of Schiff Base Derived from Isatin with Thiocarbohydrazide and Their Cu(II) And Zn(II) Complexes

Abstract

A Schiff base ligand, N,2-bis(2-oxoindolin-3-ylidene)hydrazine-1-carbothiohydrazine (B1) was synthesized via condensation reaction of isatin and thiocarbohydrazide. The ligand was reacted with copper(II) acetate monohydrate and zinc(II) chloride producing N,2-bis(2oxoindolin-3-ylidene)hydrazine-1-carbothiohydrazinecopper(II) (CuB1) and N,2-bis(2oxoindolin-3-ylidene)hydrazine-1-carbothiohydrazinezinc(II) (ZnB1). The ligand structures and its together with copper and zinc complexes were characterized using elemental analysis, melting point, infrared spectroscopy, 1H and13C Nuclear Magnetic Resonance spectroscopy and UV-Visible spectroscopy. In this study, the optimized structures of the compounds were calculated using the B3LYP hybrid function with a DNP basis set to evaluate the electronic properties of the compounds. The antibacterial screening using microtitre-plate assay was conducted against Streptococcus mutans Clarke (ATCC 700610) and Staphylococcus aureus subsp. aureus Rosenbach (ATCC 6538) and no significant activity were reported.