KINETICS OF THE REDUCTION OF TETRAAZA MACROCYCLIC COMPLEX CU(TAAB)2+ BY GLUTATHIONE

The reduction of a copper(II) complex with the macrocyclic ligand aben zo[b,f,j,n]-[1,5,9,13]-tetraazacyclohexadecine by glutathione in aqueo us solution has been investigated spectrophotometrically in both anaer obic and aerobic conditions. The reaction rate is first-order with res pect to the concentration of reactants. According to the values of act ivation parameters and the course of spectral change during the reacti on, an outer-sphere redox mechanism has been suggested. The copper com plex initiates the catalytic oxidation of glutathione by dioxygen. The results are compared with the catalytic effect of Cu(TAAB)2+ at the o xidation of ascorbic acid and hydroxylamine.