Gold with +4 oxidation state compounds: mass spectrometric and theoretical characterization of AuO2+

Abstract

Using an ab initio methodology and mass spectrometric study we identify AuO²⁺ as a metastable species in the gas phase. This represents the first characterization of a gas phase compound of gold with the oxidation state +4. Computations show that this dication exhibits deep potential wells with long lived electronic states. Its electronic ground state is of ⁴∑⁻ symmetry, which is known for very few molecular ground states. We also discussed the O + Au²⁺ collision dynamics, which leads mostly to charge transfer to form Au⁺ and O⁺ species. This identification may help in identifying new routes for the reactivity of gold in the gas phase, in solution and in the condensed phase.