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 chemistry; in particular, the structural and functional modeling of active sites 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 studies 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 characterized. Chemical, electrochemical and magnetic properties of these clusters have given much insight into the structure and function of the native enzyme. Here, we review recent efforts in inorganic model complex chemistry towards modeling the tetramanganese active site of PS II.