Anion Photoelectron Spectroscopy and Density Functional Study of Small Aluminum−Vanadium Oxide Clusters

Small aluminum−vanadium oxide clusters, AlVOy− (y = 1−3) and AlxVO2− (x = 2, 3), were investigated with anion photoelectron spectroscopy and density functional calculations. The adiabatic detachment energies of AlVOy− were estimated to be 1.06 ± 0.05, 1.50 ± 0.08, and 2.83 ± 0.08 eV for y = 1, 2, and 3. Those of Al2VO2− and Al3VO2− were estimated to be 1.22 ± 0.08 and 1.25 ± 0.08 eV. Comparison of theoretical calculations with experimental measurement suggests that the most probable structure of AlVO− cluster is quasilinear with O atom in the middle. AlVO2− has an irregular chain structure of Al−O−V−O and a C2v cyclic structure very close in energy. The structure of AlVO3− cluster is evolved from the C2v cyclic AlVO2− structure by adding the third O atom to the V atom. Al2VO2− has a pair of nearly degenerate Al−O−V−O−Al chain structures that can be considered as cis and trans forms. Al3VO2− probably has two low-lying isomers each containing a four-membered ring. The structures of the corresponding neutral clusters are discussed.