Metal Cluster Topology. 4. Rhodium Carbonyl Clusters Having Fused Polyhedra

摘要

Previously discussed topological models of metal cluster bonding are now extended to the treatment of anionic rhodium carbonyl clusters having structures consisting of fused polyhedra. Examples of such rhodium carbonyl clusters built from fused octahedra include the biphenyl analogue Rh12(CO)30(-2), the face-sharing naphthalene analogue Rh9(CO)19(3-), and the perinaphthene analogue, Rh11(CO)23(3-). More complicated anionic rhodium carbonyl clusters treated in this paer include the Rh13(CO)24H5-q(q-) anions (q = 2,3,4) having an Rh13 centered cuboctahedron, the Rh14(CO)25H4-q(q-) (q = 3,4) and Rh14(CO)26(2-) anions based on a centered pentacapped cube, the Rh15(CO)30(3-) anion having an Rh15 centered 14-vertex deltahedron, the Rh15(CO)27(3-) anion having a tricapped centered 11-vertex polyhedron, the Rh17(CO)30(3-) anion having a tetracapped centered cuboctahedron, and the Rh22(CO)37(4-) anion having a hexacapped centered cuboctahedron fused to an octahedron so that the octahedron and the cuboctahedron share a triangular face. Analyses of the bonding topologies in Rh9(CO)19(3-), Rh17(CO)30(3-), and Rh22(CO)37(4-) indicate that a polyhedral network containing several fused globally delocalized polyhedral chambers will not necessarily have a multicenter core bond in the center of each such polyhedral chamber. This observation is of potential importance in extending topological models of metal cluster bonding to bulk metals.