Transimination; a Synthetic Route to Mixed Ligand Schiff Base Complexes

Copper and nickel Schiff base complexes have been prepared and reacted with aqueous ammonia and some amines. A variety of Schiff bases have been chosen, two bidentate Schiff bases; HSN and HNPY which are N-(2-hydroxy-1-naphthalidine)-3-aminopyridine and Nsalicylidinenaphthylamine, respectively, three tridentate Schiff bases; HBN, HPN and HBS which are N-2-hydroxynaphthalidine-2-aminobenzoic acid, N-2-hydroxynaphtalidine-2-aminophenol and N-salicylidne-2-aminobenzoic acid, respectively, and one tetradentate Schiff base which is N,N-(salicylidine)-4,5-dimethylphenylendiamine (H2Sal2Me2Ph). The complexes derived from the bidentate and the tetradentate Schiff bases; [M(NPY)2], [M(SN)2] and [M(Sal2Me2Ph)] (M= Cu and Ni), undergo transimination reaction with a complete loss of the exchanged amine from the coordination sphere. However, in case of the tridentate Schiff base complexes, M(PN), M(BN), M(BS), amine exchange took place and the eliminated amine gets bonded to the metal, which produced new type of mixed Schiff base complexes.