Addition of water and methanol to Al3O3− studied by mass spectrometry and anion photoelectron spectroscopy

Abstract

The 4.66 eV photoelectron spectra of Al3O3−, Al3O3−⋅solvent and Al3O3−⋅(solvent)2 (solvent=H2O, D2O, and CH3OH) have been obtained and analyzed in the context of existing and preliminary new density functional theory calculations. The structures and vibrational frequencies of the two isomers of Al3O3− and Al3O3 proposed by Ghanty and Davidson [J. Phys. Chem. A 103, 8985 (1999)] agree well with structural information extracted from the Al3O3− spectra using Franck–Condon simulations. Photoelectron spectra of Al3O3−⋅solvent complexes [EA=2.5(1) eV] are broad and congested, and hydroxide formation, multiple structural isomers, and anion photodissociation are suggested as possible sources of this. The photoelectron spectra of Al3O3−⋅(solvent)2 complex spectra [EA=3.05(10) eV] show two distinct electronic transitions, several of which exhibit partially-resolved vibrational structure that are similar to the two electronic bands attributed to the bare rectangular structural isomer of Al3O3−. Possible adsorption scenarios are suggested, with hydroxide formation being the most consistent with trends observed in both the photoelectron and mass spectra.