HIGH-VALENT OXOMANGANESE CLUSTERS - STRUCTURAL AND MECHANISTIC WORK RELEVANT TO THE OXYGEN-EVOLVING CENTER IN PHOTOSYSTEM-II

Recent years have seen a considerable interest in bioinorganic chemist ry; in particular, the structural and functional modeling of active si tes of metalloproteins. The oxomanganese tetramer in the O-2-evolving center (OEC) in photosystem II (PS II) of plants is thought to be the site of water oxidation to dioxygen. In conjunction with biophysical s tudies on the enzyme, inorganic chemists are trying to understand the structural and mechanistic aspects of the OEC by studying oxomanganese clusters. A number of such clusters, varying in nuclearity, ligation, and type and number of ore-bridges, have been synthesized and charact erized. Chemical, electrochemical and magnetic properties of these clu sters have given much insight into the structure and function of the n ative enzyme. Here, we review recent efforts in inorganic model comple x chemistry towards modeling the tetramanganese active site of PS II.