The Topology of the Total Charge Density in Binuclear Transition-Metal Complexes That Formally Contain Metal-Metal Bonds

Abstract

The quantum theory of atoms in molecules and the topological theory of molecular structure define atoms and bonds, respectively, in terms of the electronic charge distribution, p(r) [1]. This identification enables X-ray crystallographers and theoretical chemists to discuss the properties of atoms and bonds using a familiar and common language. The results from the first such analysis of transition-metal complexes will be presented. The binuclear systems Mn₂(CO)₁₀, Fe₂(CO)₉ and Co₂(CO)₈ have been studied to determine whether or not their corresponding molecular structures contain metal-metal bonds. At a level of theory that is generally found to be sufficient for predicting chemical structures (i.e. the network of topologically defined bond paths that link the atoms as opposed to the precise geometrical structure of the molecule), only Mn₂(CO)₁₀ possesses a metal-metal bond.