Electrocatalytic water oxidation by Cu^II complexes with branched peptides

Abstract

Two mononuclear Cu(II) complexes with tetrapeptides incorporating a L-2,3-diaminopropionic acid (dap) branching unit are reported to undergo PCET and catalyse water oxidation. C-terminal His extension of dap (L = 2GH) instead of Gly (L = 3G) lowers the pKa for Cu(III)H-2L (9.36 vs. 9.98) and improves the TOF at pH 11 (53 vs. 24 s(-1)).