Synthesis, Characterization, and Antibacterial Activity of the Schiff Bases Derived from Thiosemicarbazide, Salicylaldehyde, 5-bromosalicylaldehyde and their Copper(II) and Nickel(II) Complexes

Abstract

Two Schiff bases salicylidene thiosemicarbazone (SALTSC) and 5-bromosalicylidene thiosemicarbazone (5-BrSALTSC) were prepared in excellent yield via the condensation of salicylaldehyde/5-bromosalicylaldehyde and thiosemicarbazide. The copper (II) and nickel (II) complexes of the Schiff base ligands (CuSALTSC, 5-BrCuSALTSC, NiSALTSC, and 5-BrNiSALTSC) were also prepared. The complexes were tested against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) using Disc diffusion method. Among these complexes, 5BrCuSALTSC was found to be highly active against S. aureus at a concentration of 100 μg/disc and against E. coli at a concentration of 150 μg/disc. 5BrNiSALTSC was found to be highly active against E. coli at a concentration of 150 μg.