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 [M₂L]Cl₂, 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 [Cu₂L]Cl₂ (inhibition) and [Ni₂L]Cl₂ (enhancement) are explained by different reduction mechanisms.