Mixed- ligand Complex Formation of Cobalt(II) Nickel(II) and Zinc(II) with N-Benzenesulphonyl-l-cysteine as Primary Ligand and Bipyridine, Ethylenediamine and Glycinate as Secondary Ligands

Department of Chemistry, University College of Science, 92 Acharya Prafulla Chandra Road. Calcutta-700 009 Manuscript received 31 October 1994, received 14 June 1995, accepted 6 July 1995 Equilibrium study on the complex formation of M2+ ions (M = Co, Ni and Zn) with N-benzenesulphonyl-7-cysteine (NBSCH2) in the presence or bipyridine, ethylenediamine, glycinate (B) indicates the formation of mixed-ligand complexes of the types M(NBSC)(B), M(H-1NBSC)(B)and M(H-1NBSC) (OH), together with binary M(NBSC) and M(B) complexes. Formation constants or the complexes have been determined by potentiometric method at 25± 0.1 in 50% (v/v) ethanol-muter medium at a constant kink strength, I= 0.2 M (NaNO3). Stability or the complexes has been correlated with the modes of coordination of NBSC, basicity of the B ligands and π electron delocalisation in the metal-ligand bonds