Building on the past studies of the O 2n- and O 2- (H2 O) m cluster anion series, we assess the effect of the strong hydration interactions on the oxygen-core clusters using photoelectron imaging and photofragment mass spectroscopy of [O2n (H2 O) m]- (n=1-4, m=0-3) at 355 nm. The results show that both pure-oxygen and hydrated clusters with n≥2 form an O4- core anion, indicated in the past work on the pure-oxygen clusters. All clusters studied can be therefore described in terms of O4- (H2 O) m (O2) n-2 structures, although the O4- core may be strongly perturbed by hydration in some of these clusters. Fragmentation of these clusters yields predominantly O2- and O 2- (H2 O) l (l<m) anionic products. The low-electron kinetic energy O O2- autodetachment features, prominent in the photoelectron images, signal that the fragments are vibrationally excited. The relative intensity of photoelectrons arising from O O2- fragment autodetachment is used to shed light on the varying degree of fragment excitation resulting from the cluster fragmentation process depending on the solvent conditions.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry