A biomimetic phenol substituent effect on the reaction of a dimethylplatinum(II) complex with oxygen: proton coupled electron transfer and multiple proton relay

The complex [PtMe₂({κ²-N,N-RNCH-2-C₅H₄N})] reacts with oxygen in acetone solution to give the platinum(IV) complex [Pt(OH)Me₂{κ³-N,N,O-RNH–CH(2-C₅H₄N)(CHCMeO)}], when R = 2-C₆H₄OH, but not when R = Ph. It has been suggested that the phenol substituent plays two key biomimetic roles; firstly, in proton coupled electron transfer reactions in the activation of oxygen and hydroperoxide groups and, secondly, in proton relay from a methyl group of the coordinated acetone.