A combined DFT and CCSD(T) study on electronic structures and stability of the M2(η5-CpX)2 (M = Zn and Cd, CpX = C5Me5 and C5H5) complexes

In the present Letter, density functional theory has been used to optimize geometries of Zn2(η5-Cp*)2 (Cp* = C5Me5). The CCSD(T) calculated dissociation energies of 41.9 and 58.5 kcal/mol for the metal–metal and metal–ligand bonds predict that Zn2(η5-Cp*)2 is a stable complex at room temperature. Ionic bond dominates the interaction between metal atom and ligand and a unique unit of Zn 2 2 + was found to exist in the complex. The Zn–Zn bond is a σ single bond, which is further strengthened by a weak d–d interaction.