Mononuclear bis(dimethylglyoximato)ruthenium(III) complexes with different appended axial groups: highly efficient catalysts for water oxidation

Abstract Mononuclear ruthenium( III ) complexes [Ru(H-dmg) 2 XY] n ( n = −1, when X = Y = Cl − or ClO 4 − n = 0 when X = Cl − and Y = imidazole or 2-methylimidazole) were used as catalysts in water oxidation to molecular oxygen by electrolytic and chemical methods. The evolved oxygen in both methods was measured at atmospheric pressure (30 °C) using a specially-designed gas volumetric apparatus. The maximum turnover number of the above complexes (mol O 2 evolved per mole complex per hour) are reported.