(CYCLOPENTADIENYL) METAL CLUSTER COMPLEXES OF THE GROUP-9 TRANSITION-METALS

Cluster complexes with metal frameworks built from [(C(5)R(5))(d(9)-M) ] units are reviewed (d(9)-M = Co, Rh, Ir). The range of additional li gands which may be attached to the [(C(5)R(5))M](n) cores includes mai n group atoms such as H, O, S and Se, small inorganic molecules such a s CO, CS, NO and NH as well as organic compounds such as isocyanides, alkynes, alkylidynes, arenes and others.Syntheses, structures and reac tivities of the known cluster complexes of this type are discussed. Sp ecial emphasis is given to the relationship of structure and chemical properties to the valence electron count in systems of similar composi tion.