Regularities in the Influence of Water-Organic Solvents on the Thermodynamics of Complex Formation: II.1 Changes in Enthalpy and Entropy of Formation of Ammonia and Carboxylate Complexes

The role of enthalpy, entropy contributions to the shift of complex formation equilibria inwater-organic solvents was studied. The formation of both ammonia and carboxylate complexes of d-metalions was found to be presumably enthalpy-controlled. The role of entropy changes increases in binary solvents with a high level of supramolecular organization, and also in the case of formation of complexes of the highest orders, when the coordination of ligands is accompanied either by a complete displacement of solvent molecules from the inner coordination sphere or by a change in the complex structure. Thus found regularities can be applied for the prediction of heat effects of complex formation in water-organic solvents. In the fist communication [1] of this series we have considered the effects of the nature and composition of water-organic solvents on the stability of ammonia and carboxylate complexes of d-metal ions. This work is based on the data of our recent thermochemical works [2-22] and is dedicated to the study of the role of enthalpy and entropy contributions to the shift of the complex formation equilibria in water-organic solvents.