High-Resolution Photoelectron Spectroscopy of Cryogenically Cooled VO ₃ H ₂ ^–

High-resolution photoelectron spectra of cryogenically cooled VO 3 H 2 – anions obtained with slow electron velocity-map imaging (cryo-SEVI) are reported. Comparison with DFT calculations shows that the spectra are from the cis -VO(OH) 2 – dissociative adduct. The same complex is formed through either the VO 2 – + H 2 O or VO 3 – + H 2 pathways, with the latter yielding significantly more ions. The experiment yields an electron affinity of 1.857(1) eV and several vibrational frequencies for the neutral species. Comparisons to Franck–Condon (FC) simulations show good agreement with the experimental features, but there are several transitions that do not appear in the simulations. These features are assigned to FC-forbidden transitions involving nontotally symmetric vibrational modes and are attributed to Herzberg–Teller (HT) coupling with the excited C̃ 1 B 2 anion state. The results are compared to the previous (cryo-SEVI) study of the titania water-split adduct, TiO 3 H 2 – to explore the role of the additional vanadium valence electron in the spectroscopy and chemistry of these adducts.