The structures and fluxional behaviour of the binary carbonyls; a new approach. Part 2. Cluster carbonyls Mm(CO)n(n= 12, 13, 14, 15, or 16)

Abstract

A systematic quantitative survey of available n-vertex polyhedra for n= 12, 13, 14, 15, and 16 has been carried out and an examination of the extent to which carbonyl positions approximate to regular or semi-regular polyhedra made. It has been shown that the structures of many carbonyl clusters, including the distribution of terminal, edge-bridging, and face-bridging carbonyl groups, may be rationalised in terms of a simple model. This model is based on the observation that carbonyl ligands pack in space so as to minimise non-bonded interactions and that the structure of M_m(CO)_n clusters is merely a reflection of the insertion of the M_m polyhedron within this (CO)_n polyhedron.