518—π-acid effect on electrode behaviour of ternary complexes in solution: Complex formation between copper(II)-1,10-phenanthroline complex and ligands containing oxygen and/or nitrogen donor atoms as secondary ligands. part II

The study of mixed-ligand complexes Cu_x(phen)_yL_z] (where phen stands for 1,10-phenanthroline and L for aliphatic acids, aromatic acids, amino acids and phenols in the ratio of 1 : 1 : 1 and 1 : 2 : 1) has been made at three different temperatures, namely 30, 35 and 40°C. It is observed that all the complexes follow a partictiar reaction mechanism with temperature, and the half-wave potential shifts towards the more positive side with rise of temperature, indicating easier reduction. Besides the formal rate constant, the activation energy of diffusion, E_D, has been calculated for each system. The effect of activation energy and the energy of rearrangement of electronic configuration of the depolarizer has been discussed against availability of the redox orbital for the electroreduction process.