Electronic structure and molecular properties of the [Mo₆X₈L₆]^2-; X = Cl, Br, I; L = F, Cl, Br, I clusters

Relativistic TDDFT calculations including spin orbit interactions via the ZORA approximation and solvent effects were carried out on the [Mo₆X₈L₆]^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 [Mo₆X₈]⁴⁺ core. Thus, our calculations and the electronic similarities with the strongly luminescent [Mo₆Cl₈Cl₆]^2-, [Mo₆Br₈Br₆]^2- and [Mo₆I₈I₆]^2- clusters, suggest that the clusters [Mo₆Cl₈F₆]^2-, [Mo₆Br₈F₆]^2-, [Mo₆I₈F₆]^2-, [Mo₆I₈Cl₆]^2- and [Mo₆I₈Br₆]^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.