On the nature of [Fe3(CO)12] in the solid-state: The Ligand Polyhedral Model approach to the observed disorder

Abstract

The Ligand Polyhedral Model (LPM) has been applied to the solid-state structure of [Fe3(CO)12] and used to account for the ‘Star of David’ disorder observed for the compound and its close relatives [Fe2Ru(CO)12] and [FeRu2(CO)12] from Single Crystal Crystallographic studies. The view is expressed that the observed disorder is a reflection of the arrangement of orientational isomers within the lattice which may be predicted from the LPM. The approach also offers the view that the asymmetric CO bridges observed for the molecular species with C2v symmetry in reality do not exist but are a reflection of the presence of the two isomeric forms C2v and D3 in the lattice. The case for LPM view of the fluxional behaviour of [Fe3(CO)12] is also restated in the light of these views of disorder and its origin.