[C5Li5]Mg n [C5Li5] (n=2-8): novel sandwich complexes containing -Mg-Mg- chain

A density functional theory (DFT) investigation on novel sandwich-type D (5) [C5Li5]Mg (n) [C5Li5] (n = 2-8) complexes containing -Mg-Mg- chain has been performed in this work. The equilibrium geometries, electronic structures, vibrational frequencies, and stabilities of these complexes are researched by B3LYP and BP86 methods at 6-311+G(d) levels of theory. The Mg (n) (2+) sandwich complexes with D (5) symmetry are all true minima on the potential energy surface. NBO analyses for the series of complexes reveal that the Mg-Mg bond is a weak sigma covalent bond. There are mainly electrostatic interactions between C5Li5 (-) ligands and Mg (n) (2+) (n = 2-8) nuclear in these complexes. The NICS and NICSzz computed with GIAO-B3LYP/6-311+G(d) indicates that the C5Li5 (-) rings in the series of complexes are aromatic. These novel complexes turn out to be strongly thermodynamically favored in the gas phases and may be targeted in future experiments to expand the structural domain of sandwich-type complexes.