Imaging the indirect dissociation dynamics of temporary negative ion: N2O- -> N2 + O-

TL;DR

This study uses imaging and ab initio calculations to explore how the N2O- negative ion dissociates via two indirect pathways, revealing how electron attachment energy influences the momentum distribution of the O- fragment.

Contribution

It identifies and characterizes two distinct indirect dissociation pathways of N2O- using combined experimental imaging and theoretical calculations.

Findings

Two dissociation pathways depend on electron attachment energy.

Different pathways lead to high vibrational or rotational states of N2.

Momentum distributions reveal pathway competition.

Abstract

We reported an imaging study of the dissociation dynamics of temporary negative ion N2O- formed in the low-energy electron attachment, e- + N2O -> N2O- -> N2 + O-. With the help of ab initio molecular dynamics calculations, the evolution of momentum distributions of the O- fragment in terms of the electron attachment energy is identified as the result of a competition between two distinctly different indirect pathways, namely, climbing over and bypassing the energy ridge after the molecular structure bending. These two pathways prefer leaving the N2 fragment at the high vibrational and rotational states, respectively.