Chemical Modelling Potentiometric Study on the Complex Formation of Ditopic Sebacic Acid Dihydrazide with Co2+ and Ni2+in Aqueous Medium

Abstract

Binary proton-ligand as well as metal-ligand equilibria of Sebacicdicarboxylic acid dihydrazide (L) with Co2+and Ni2+were studied by pH-potentiometric method at 30 0C and I=0.1M (NaCl). Sebacic acid dihydrazide is an aliphatic polydentate ditopic ligand that can bind metal ions through two hydrazide groups present at the ends of a long linear –(CH2)8- hydrocarbon chain. This enables the ligand to form both mononuclear and binuclear species. The potentiometric data acquired were analysed chemometrically using the Miniquad-75 program. The complexes that converged include protonated (MLH, ML2H and ML2H2) and deprotonated forms (MLH-1 and ML2H-1) along with the simple unprotonated ML and ML2 types. The formation of homo-binuclear species of type M2L and M2LH-1 was also noticed.