Electronic structures of AlMoO _y ^- (y = 1-4) determined by photoelectron spectroscopy and density functional theory calculations

Vibrationally-resolved photoelectron spectra of AlMoO _y ^- (y = 1-4) are presented and analyzed in conjunction with density functional theory computational results. The structures determined for the AlMoO _y anion and neutral clusters suggest ionic bonding between Al ⁺ and a MoO _y ^- or MoO _y ^-2 moiety, and point to the relative stability of MoO versus AlO bonds. The highest occupied and partially occupied orbitals in the anions and neutrals can be described as Mo atomic-like orbitals, so while the Mo is in a higher oxidation state than Al, the most energetically accessible electrons are localized on the molybdenum center.