Potentiometric and thermal conductimetric studies on salicylidene Girard-P hydrazone complexes of divalent Co,Ni, Cu and Zn salts

Salicylidene Girard-P hydrazone [H₂L]Cl reacts with divalent cobalt, nickel, copper and zinc ions to form mono-ligand complexes of the type [ML·H₂O]Cl·nH₂O and [(CuL)₂]Cl₂. The formation constants of the complexesML were determined in 50% (v/v) aqueous ethanol solution at an ionic strengthl=0.1M KCl and at 25±0.1°C. The solid complexes and the ligand were subjected to differential thermal analysis and the DC electrical conductivities were measured at varying temperatures. The results obtained were explained and discussed in terms of the proposed semiconductive behaviour of the complexes and the probable occurrence of a phase transition. The activation energies (ΔE) were calculated for the ligand and the complexes; that of the ligand was higher than those of the complexes.