Oxygen Evolution by Water Oxidation Mediated by Heterogeneous Manganese Complexes

The catalytic oxidative decomposition of water has been achieved with the help of the dinuclear manganese complexes 1 and 2, which are models for compounds participating in photosynthesis. Whereas no reaction was observed in homogeneous solution, O 2 evolution took place almost immediately in the heterogeneous phase after addition of a Ce IV salt as oxidizing agent. This finding supports the assumption that a microheterogeneous environment and a large spatial proximity of the manganese centers are essential for the photosynthetic activity of manganese compunds (bpy=2,2'-bipyridyl; phen=1,10-phenanthroline).