Spectrophotometric and Thermodynamic Studies of 1,3-Bis- (2-cyanobenzene)triazene Complexes with Hg2+ and Cd2+ Ions

Abstract

The complexation reactions between 1,3-bis(2-cyanobenzene)- triazene (CBT) with Hg²⁺ and Cd²⁺ ions have been studied using spectrophotometry in acetonitrile at various temperatures. The formation constants of the resulting 1:1 and 1:2 (metal ion to ligand) complexes were calculated from the computer fitting of the absorbance mole ratio data. At 25 °C the stability constant of the Hg²⁺ complex is higher than the Cd²⁺ complex. The enthalpy and entropy changes of the complexation reactions were also evaluated from the temperature varied formation constants.