METAL-CARBORANE MULTIDECKER SANDWICH COMPLEXES AS BUILDING-BLOCKS FORNEW MATERIALS

Transition-metal sandwich complexes incorporating bifacially coordinat ed C2B3 planar carborane rings form a large and varied family of gener ally air-stable, highly robust compounds that feature multidecker stac king. As a group, these complexes offer a number of advantages that ar e potentially of interest in the development of new electronic, magnet ic and/or optical materials, They are remarkably versatile, accommodat ing a wide range of metals and organic substituents; they are soluble in organic solvents and are typically resistant to air and moisture; t hey can be reversibly oxidized and reduced; in many cases they are par amagnetic, exhibiting substantial electron delocalization of the unpai red electrons between metal centers. Moreover, the small carborane sta rting materials can now be prepared in large (ca 100 g) quantities, ma king the complexes readily accessible. A brief overview of this area i s presented with emphasis on the systematic utilization of metallacarb orane sandwich complexes in the construction of large multimetallic sy stems and studies of their electronic and molecular structures.