Synthesis, characterization, crystal structure and bioactivities of a new potential tridentate (ONS) Schiff base ligand N-[2-(benzylthio) phenyl] salicylaldimine and its Ni(II), Cu(II) and Co(II) complexes

Abstract

A series of new bichelated complexes of the formula [M(L)2]·H2O were synthesized from the reaction of N-[(2-benzylthio)-phenyl] salicylaldimine (HL), 1, a new tridentate (O, N, S donor) potential Schiff base with metal salts in methanol medium. These compounds were characterized by elemental analyses, FT-IR, UV–Visible and magnetic susceptibility studies. The crystal structures of the ligand 1 as well as two nickel(II) complexes [Ni(L)2]·H2O, 2 and 3, were determined by X-ray diffraction studies. The nickel atom is coordinated to two oxygen atoms, two nitrogen atoms and two sulfur atoms in bichelated fashion of the ligand, 1 indicating that the metal atom is in a slightly distorted octahedral environment. The bioactivity studies showed that the ligand and the complexes exhibit considerable antibacterial and antifungal activities against Bacillus subtilis (Gram +ve), Klebsiella pneumonia (Gram −ve) and Candida albicans.