Studies on ion association: thermodynamics of thiocyanate complexes of some bivalent metal ions

Abstract

Silver-silver thiocyanate electrode has been utilised to determine the free energy changes of the complex formation reactions of monothiocyanato complexes of Mn^II, Co^II, Ni^II and Cd^II which are shown to be more accurate than the previously determined values. The enthalpy and entropy changes have been calculated from the temperature coefficient of K. It is shown that the complexes are of innersphere type with bonding through the nitrogen atom. The crystal field stabilisation energies have also been calculated from the enthalpy changes.