Macrocyclic binuclear copper(II) and nickel(II) complexes: the key role of central ions in hydrogen peroxide electrocatalysis

The electrochemistry of the macrocyclic dicopper(II) and dinickel(II) complexes [M 2L]Cl 2, where L is the [2+2] condensation product of 1,3-diaminopropane and 2,6-diformyl-4- tert-butylphenol, is reported in relation to hydrogen peroxide electrocatalysis on mercury. The opposite effects observed with [Cu 2L]Cl 2 (inhibition) and [Ni 2L]Cl 2 (enhancement) are explained by different reduction mechanisms.