Structural, antimicrobial and spectral studies of copper(II) complexes of 2-benzoylpyridine N(4)-phenyl thiosemicarbazone

Abstract

Reaction of 2-benzoylpyridine N(4)-phenyl thiosemicarbazone (HL) with a variety of copper salts yielded a series of copper(II) complexes of the type [CuLX] where X = Cl ( 1), Br ( 2), NO 3 ( 3), NCS ( 4), N 3 ( 5) excluding the perchlorate complex. In the perchlorate complex ( 6), one molecule each of the neutral and deprotonated ligand is found to be coordinated to the metal. The complexes are characterized by molar conductivity measurements, magnetic studies, electronic, infrared and EPR spectral studies. The crystal structures of two copper complexes, 1 and 4 have been resolved using single crystal X-ray studies. The crystal structure of compound 1 revealed chlorine bridged dimer having monoclinic lattice with space group symmetry P2 1/ c. The compound 4 adopts a distorted square planar geometry with N 3S core as the base. The antimicrobial activity of the ligand and the copper complexes were tested against five types of bacteria isolated from clinical samples. The ligand (HL) was found to be active against Staphylococcus aureus. The copper(II) complexes were found to be active against Vibrio cholerae O1 and Salmonella paratyphi.