On the electronic structure of mono-rhenium oxide clusters: and ReOn (n = 3, 4)

We report a photoelectron spectroscopy and density-functional study on mono-rhenium oxide clusters: ReO n - and ReOn (n = 3, 4). Electron affinities of ReO3 and ReO4 are measured to be 3.53 ± 0.05 and 5.58 ± 0.03 eV. ReO 3 - is shown to possess a planar D3h ( 1 A 1 ′ ) ground state and ReO3 adopts a nonplanar C3v (2A1) structure. ReO 4 - has Td (1A1) structure, whereas ReO4 has Cs (2A′) symmetry due to Jahn–Teller effects and contains a Re–O radical unit. Localized Re 5d electrons in ReO 3 - and ReO3 give rise to Re5+ and Re6+ centers, making them simple models for O2 activation.