Electronic structure and molecular properties of paramagnetic hexanuclear Tantalum [Ta6X12Y6]3− (X and Y = F, Cl, Br, I) cluster compounds

Abstract

Relativistic density functional calculations were carried out on several Tantalum cluster of the general formula [Ta6X12Y6]3−, with the aim to characterize and analyze their molecular structure and electronic properties, in order to gain more insights into their stability and reactivity. Herein are reported the geometrical parameters, electronic structures, excitation energies and magnetic properties, of a series of clusters that have been and have not been yet synthesized. The calculated Δg tensor shows that as the halide capping ligand become heavier the Δg tensor values increases due to spin–orbit effects. Through the use of the reactivity indexes it is shown that when the axial ligand is iodine it becomes the most reactive and labile ligand. The TD-DFT calculations on the complete [Ta6X12Y6]3− cluster family show good agreement with the available experimental data.