Schiff base complexes of some metal ions with vanillin and amino acids

Department of Chemistry, Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli-627 012, Tamilnadu, India
E-mail: msnairchem@rediffmail.com
Manuscript received 17 April 2007, accepted 4 June 2007

Equilibrium studies on the Schiff base complex systems, viz. Co^II, Ni^II, Cu^II and Zn^II-vanillin(van)(A)-L-valinc(val )/L-glutamine(gln)/ L-glutamic acid(glu)/L.-histidine(his)(B) demonstrate the presence of MAB, MA₂B or MA₂B₂ complexes. The stability constant values in the M^II-von-val/gln/lglu systems indicate that the Schiff base ligand (AB) is tridentate in its M(AB) complexes, while it is tctradentate in the M^II-van-his systems. The results show that the MA₂B and MA₂B₂ complexes can best be represented respectively as M(AD)A and M(AB)z-