Conductometric and Spectrophotometric Studies of Thermodynamics of Complexation of Zn2+, Ni2+, Co2+, Pb2+ and Cu2+ Ions With 2,2'-Dimethyl-4,4'-bithiazole in Acetonitrile Solution

Abstract

In this work, the complexation reactions between 2,2'-dimethyl-4,4'- bithiazole (DMDTZ) and Zn²⁺, Ni²⁺, Co²⁺, Cd²⁺, Pb²⁺ and Cu²⁺ ions were studied conductometrically and spectrophotometrically in acetonitrile solution at various temperatures. The formation constants of the resulting 1:2 complexes were calculated from the computer fitting of the molar conductance-mole ratio data at different temperatures. At 25 ºC, the stability of the resulting complexes varied in the order Zn²⁺ > Ni²⁺ > Cu²⁺ > Co²⁺ > Cd²⁺ > Pb²⁺. The enthalpy and entropy changes of the complexation reactions were evaluated from the temperature dependence of formation constants.