Fluxional behaviour of the carbonyls [M3(CO)12](M = Fe, Ru or Os)

Abstract

A study of the crystal structures of the carbonyls [M₃(CO)₁₂](M = Fe, Ru or Os) and a series of their derivatives [M₃(CO)_12–nL_n] has revealed good evidence in support of the hypothesis that the mechanism of ligand fluxionality goes via the intermediacy of an anticubeoctahedral complementary geometry. Several examples of systems with an icosahedral distribution of ligands and quasi-D₃ symmetry have been identified providing additional support for our earlier suggestion that a second isomer of [Fe₃(CO)₁₂], which exists in solution, adopts a similar D₃ structure.