Département de chimie moléculaire

A review. The extensive chem. of oxido-bridged multinuclear manganese complexes arises to a large extent from their relevance to redox-active metalloenzymes such as manganese catalases and the oxygen-evolving complex of photosystem II contg., as active centers, oxido- and carboxylato-bridged dinuclear and tetranuclear Mn complexes, resp. During the enzymic catalytic cycles the oxidn. state changes of the Mn ions induce some structural changes of these active centers such as the formation of oxido bridges. In this area, this review is focused on examples from the literature of the formation and transformation of oxido-bridged multinuclear manganese complexes that are induced by electrochem. or photochem. means. Representative examples of such transformations are provided by polypyridyl Mn complexes, with interconversion between mononuclear, dinuclear and tetranuclear cores accompanied by the concomitant formation or breaking of $μ$-oxido bridges. Other important examples are furnished by dinuclear Mn complexes having multipodal amino-pyridyl ligands, some of which contain phenolic units, for which a clean interconversion between $μ$-oxido and $μ$-acetato bridges are obsd. [on SciFinder(R)]