Quantum calculations of the photoelectron spectra of the OH - ·NH 3 anion: implications for OH + NH 3 → H 2 O + NH 2 reaction dynamics

We present the results of quantum dynamics calculations for analyzing the experimentally measured photoelectron spectra of the OH ·NH anion complex. Detachment of an excess electron of OH ·NH initially produces a molecular arrangement, which is close to the transition-state structure of the neutral OH + NH → H O + NH hydrogen abstraction reaction due to the Franck-Condon principle, and thus finally leads to the OH + NH or H O + NH asymptotic channel. We used both the path integral method and the reduced-dimensionality quantum wave packet method to simulate the photoelectron spectra of the OH ·NH anion. The calculated spectra were found to be in qualitative agreement with the experimental spectra. It was found that the photodetached complex mainly dissociates into the OH + NH channel; however, we found that the hydrogen exchange process also contributes to the photodetachment spectra.