Vibrationally Resolved Photoelectron Imaging of Cu2H– and AgCuH– and Theoretical Calculations

Vibrationally resolved photoelectron spectra have been obtained for Cu2H– and AgCuH– using photoelectron imaging at 355 nm. Two transition bands X and A are observed for each spectrum. The X bands in both spectra show the vibration progressions of the Cu–H stretching mode and the broad peaks of these progressions indicate significant structural changes from Cu2H– and AgCuH– to their neutral ground states. The A bands in the spectra of Cu2H– and CuAgH– show stretching progressions of Cu–Cu and Ag–Cu, respectively. The contours of these two progressions are pretty narrow, indicating relatively small structural changes from Cu2H– and AgCuH– to their neutral excited states. Calculations based on density functional theory indicate that the ground states of Cu2H– and AgCuH– and the first excited states of their neutrals are linear, whereas their neutral ground states are bent. The photoelectron detachment energies and vibrational frequencies from these calculations are in good agreement with the experimental ob...