Femtosecond multi-dimensional imaging of a molecular dissociation
Although the femtosecond motions governing chemical processes occur in the frame of the molecule, orientationally averaged lab frame measurements may conceal information. Here we study the complete process—reactant to product—of the photodissociation (NO)2 → NO(A) + NO(X), from the molecule's point of view, by combining Time-Resolved Photoelectron Spectroscopy with Coincidence Imaging Spectroscopy (CIS) and ab initio computation. The multidimentional CIS method relies upon pairs of 3D particle imaging detectors used in coincidence, allowing for recoil frame measurements. We unveil a complex process involving intermediate electronic configurations which was until now obscure, illistrating the power of this approach.