Synthesis and structural characterization of an unsymmetrical (μ-OXO)-DI-(μ-acetato) manganese(III,III) complex ([Mn<inf>2</inf>O(OAc)<inf>2</inf>(H<inf>2</inf>O)(NO3)(bpy) <inf>2</inf>](ClO<inf>4</inf>) · CH<inf>3</inf>COOH)

The Ce4+ oxidation of Mn2+ in acetic acid in the presence of 2,2′-bipyridine gives the unsymmetrical complex [Mn2O(OAc)2(H2O)(NO3)(bpy) 2](ClO4) · CH3COOH. The crystal structure of the complex shows the coordination of both nitrate and water to the metal ion. Each metal centre exhibits Jahn-Teller distortion and results in two types of Mn - OOAc bonds. The formation of different high-valent manganese complexes by Ce4+ oxidation under different conditions is discussed in the light of possible disproportionation and proton-coupled electron transfer reactions. The mode of (pseudo) Jahn-Teller distortion seen in manganese(III,III) complexes having the Mn2O(OAc)2+2 core is reviewed. Copyright © 1996 Elsevier Science Ltd.