Platinum and Gold Clusters

Platinum clusters generally do not agree with the electronic requirements of transitions metal clusters established by the polyhedral Skeletal Electron Pair Theory. These clusters generally possess fewer electrons than expected from this theory. 

The electron count in a series of platinum clusters can be seen in Table 2.18. The reason why that occurs appears to be the high energy of the atomic p -orbital. The molecular orbitals derived from this orbital perpendicular to the metal-ligand plane are also high-lying and unavailable for bonding. 

The total electron count for a condensed polyhedron is the sum of the electron counts of parent polyhedra e.g. fusion of two closo metal deltahedra a) with  

Mingos DMP, May AS (1990) In Shriver DF, Kaesz HD, Adams RD (eds) The chemistry of metal cluster complexes. VCH, New York, p. 11 Mingos DMP, Johnston RL (1987) Struc. Bonding 68 29 MacPartlin M, DMP Mingos (1984) Polyhedron 3 1321 

Triagonal pyramid Edge-bridged tetrahedron Triagonal prism 

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