Formation and characterization of the oxygen-rich scandium oxide/dioxygen complexes ScOn (n = 4, 6, 8) in solid argon.

The reactions of scandium atoms and O(2) have been reinvestigated using matrix isolation infrared spectroscopy and density functional theory calculations. A series of new oxygen-rich scandium oxide/dioxygen complexes were prepared and characterized. The ground state scandium atoms react with dioxygen to form OSc(eta(2)-O(3)), a side-on bonded scandium monoxide-ozonide complex. The OSc(eta(2)-O(3)) complex rearranges to a more stable Sc(eta(2)-O(2))(2) isomer under visible light irradiation, which is characterized to be a side-on bonded superoxo scandium peroxide complex. The homoleptic trisuperoxo scandium complex, Sc(eta(2)-O(2))(3), and the superoxo scandium bisozonide complex, (eta(2)-O(2))Sc(eta(2)-O(3))(2), are also formed upon sample annealing. The Sc(eta(2)-O(2))(3) complex is determined to have a D(3h) symmetry with three equivalent side-on bonded superoxo ligands around the scandium atom. The (eta(2)-O(2))Sc(eta(2)-O(3))(2) complex has a C(2) symmetry with two equivalent side-on bonded O3 ligands and one side-on bonded superoxo ligand.