Theoretical study on the series of [Au(3)Cl (3)M (2)] complexes, with M = Li, Na, K, Rb, Cs.

The prediction of the series of complexes [Au(3)Cl(3)M(2)] with M = Li, Na, K, Rb and Cs, has been achieved at the ab initio level of theory. All geometries were fully optimized at the MP2 level of theory; the central Au(3) cluster is capped by chlorine atoms and the alkaline metals lie above and below the plane of the central ring; aurophilic interactions were found on the metal cluster, and also a strong aromatic character coming from the delocalized d-electrons of the Au atoms according to nuclear independent chemical shift calculations. On the other hand, the chemical hardness parameter was used to test the stability of the series of complexes, and the Fukui indexes of electrophilic and nucleophilic attack were employed to explore possible sites where chemical reactivity may play a role.