Experimental Electron Density Analysis of Mn2(CO)10: Metal−Metal and Metal−Ligand Bond Characterization

Abstract

The experimental electron density ρ(r) of Mn₂(CO)₁₀ was determined by a multipole analysis of accurate X-ray diffraction data at 120 K. The quantum theory of atoms in molecules (QTAM) was applied to ρ(r) and its Laplacian ∇²ρ(r). The QTAM analysis of ρ(r) showed the presence of a bond critical point (r_c); its associated bond path connects the two Mn atoms, but no cross interaction line was found between one manganese and the equatorial carbonyls of the other. The distribution of ∇²ρ(r) indicated “closed-shell” interactions for the metallic Mn−Mn bond and the dative Mn−CO bonds. The values of the topological parameters of the density at r_c, ρ(r_c), ∇²ρ(r_c), G(r_c) (kinetic energy density), and V(r_c) (potential energy density), characterize the bonds and are intermediate to those corresponding to typical ionic and covalent bonds.