Femtosecond Multidimensional Imaging of a Molecular Dissociation

Abstract

The coupled electronic and vibrational motions governing chemical processes are best viewed from the molecule's point of view—the molecular frame. Measurements made in the laboratory frame often conceal information because of the random orientations the molecule can take. We used a combination of time-resolved photoelectron spectroscopy, multidimensional coincidence imaging spectroscopy, and ab initio computation to trace a complete reactant-to-product pathway—the photodissociation of the nitric oxide dimer—from the molecule's point of view, on the femtosecond time scale. This method revealed an elusive photochemical process involving intermediate electronic configurations.