Experimental electron density analysis of Mn-2(CO)(10): Metal-metal and metal-ligand bond characterization

The experimental electron density p(r) of Mn-2(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 p(r) and its Laplacian del(2)p(r). The QTAM analysis of p(r) showed the presence of a bond critica l 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 c arbonyls of the other. The distribution of del(2)p(r) indicated "closed-she ll" interactions for the metallic Mn-Mn bond and the dative Mn-CO bonds. Th e values of the topological parameters of the density at r(c), p(r(c)), del (2)p(r(c)), G(r(c)) (kinetic energy density), and V(r(c)) (potential energy density), characterize the bonds and are intermediate to those correspondi ng to typical ionic and covalent bonds.