Unique Functions of Metal Complexes Inspired by Control of Coordination Environment around Metal Ions

Biological functions in metallo-enzymes are induced by the unique first and secondary coordination spheres around the metal ions of active centers. We designed and prepared some structural and functional model complexes with their unique coordination spheres, such as oxygenases, oxidases, tyrosinase, hemocyanine, hemerythrin, methane monooxygenase, nitrile hydratase, photosynthesis, nitrogenase, siderophore, and so on, and tried not only basic elucidations of their structure-function relationships but also industrial development of their functions. Here we describe some examples as follows; (i) from the stable capture of active oxygen species to their activations, (ii) from the selective preparations of bis( m -oxo)dicopper(III) and m - h 2 : h 2 -peroxo dicopper(II) complexes to clarification of tyrosinase function, (iii) from hemerythrin functional model (reversible dioxygen binding) to cathode of fuel cell (four-electron reduction of dioxygen), and (iv) from the construction of nitrile hydratase functional model to NO sensor.