LINEAR FREE-ENERGY RELATIONSHIP IN COORDI NATION CHEMISTRY .21. STUDIES ON THE FORMATION AND ACID-INDUCED DECOMPOSITION OF COPPER(II)-13-(2'-HYDROXYL)-SUBSTITUTED NZYL-1,4,8,11-TETRAAZACYCLOTETRADECANE-12,14-DIONE COMPLEXES

Complexation study on the Cu(II) complexes of ligands 13-(2'-hydroxyl) -substituted nzyl-1,4,8,11-tetraazacyclotetradecane-12,14-dione has be en carried out by pH potentiometric titration at 25 degrees C, I = 0.1 0mol . dm(-3)(KNO3). The protonation constants of ligands and the form ation constants of complexes were obtained. The coordination form of l igands with copper(II) and the stability of complexes were discussed. A kinetic study of acid-induced decomposition for these ligands' Cu(II ) complexes has also been investigated, in which reaction mechanism wa s postulated, and the rate constants were calculated. The results show there exists LFER between equilibrium constants of complexes and prot onation constants oi ligands. Good Bronsted-type LFER between rate con stants and equilibrium constants of complexes has also been found. The effects of macrocyclic substituents on the formation and the decompos ition ui complexes were also discussed.