Electronic structure and molecular properties of the [Mo 6X 8L 6] 2−; X = Cl, Br, I; L = F, Cl, Br, I clusters

Abstract

Relativistic TDDFT calculations including spin orbit interactions via the ZORA approximation and solvent effects were carried out on the [Mo 6X 8L 6] 2− X = Cl, Br, I ; L = F, Cl, Br, I clusters. These calculations indicate that the closely spaced lowest excited states are largely centered on the cubic [Mo 6X 8] 4+ core. Thus, our calculations and the electronic similarities with the strongly luminescent [Mo 6Cl 8Cl 6] 2−, [Mo 6Br 8Br 6] 2− and [Mo 6I 8I 6] 2− clusters, suggest that the clusters [Mo 6Cl 8F 6] 2−, [Mo 6Br 8F 6] 2−, [Mo 6I 8F 6] 2−, [Mo 6I 8Cl 6] 2− and [Mo 6I 8Br 6] 2− studied here might be also luminescent. The calculated bond energies and reactivity indexes indicate that the most labile clusters are those with axial iodide ligands.