Coordination chemistry and biological activity of two tridentate ONS and NNS Schiff bases derived from S-benzyldithiocarbazate

Two tridentate Schiff bases having ONS and NNS donor sequences were prepare d by condensing S-benzyldithiocarbazate (NH2NHCSSCH2Ph) (SBDTC) with pyridi ne-2-carboxaldehyde and salicylaldehyde, respectively. Complexes of these l igands with Ni-II, Zn-II, Cr-III, Co-II, Cu-II, and Sn-II were studied and characterized by elemental analyses and various physico-chemical techniques . Ni-II, Cu-II, Zn-II and Sn-II complexes were four-coordinate while the Cr -III, Sr-III and Co-III complexes were six-coordinate. The ONS Schiff base was moderately active against leukemia, while its zinc, antimony and cobalt complexes were strongly active against leukemic cells with DC50 = 0.35-5.0 0.