Distorted tetrahedral bis-(N,S) bidentate Schiff base complexes of Ni(II), Cu(II) and Zn(II): Synthesis, characterization and biological studies

Abstract Transition metal complexes of acetophenone-S-allyldithiocarbazate [H-(Ap-sadtc)] of the general formula [M-(Ap-sadtc) 2 ] (Ni 2+ , Cu 2+ , Zn 2+ ) ( 1 – 3 ) were synthesized and characterized by elemental analysis, UV–Vis, FT-IR, 1 H NMR, 13 C NMR and mass spectroscopy. The molecular structures of the ligand and its complexes 1 – 3 were confirmed by both theoretical as well as experimental methods. The interactions of the complexes with biomolecules, such as calf thymus DNA (CT-DNA) and bovine serum albumin (BSA), were explored using absorption and emission spectral techniques. All the complexes synthesized were found to be most promising due to their large binding affinity towards different bio-macromolecules and higher K cat values in catechol oxidation (3,5-DTBC)/phosphate hydrolysis (4-NPP) reactions. The in vitro anticancer activities using MTT and a morphological staining assay indicate that the complexes are active against the (Hela) cervical cancer cell line, which is consistent with our above mentioned hypothesis.