Femtosecond Time-Resolved Photoelectron Angular Distributions Probed during Photodissociation ofNO2

Femtosecond time-resolved photoelectron angular distributions (PADs) are measured for the first time in the molecular frame of a dissociating molecule. Various stages of the dissociation process, NO{sub 2}{yields} NO(C {pi}{sup 2})+O(P{sup 3}) , are probed using ionization of the NO(C {pi}{sup 2}) fragment to NO{sup +}( X {sigma}{sup +1}) . The PADs evolve from forward-backward asymmetric with respect to the dissociation axis at short time delays ({ =}1 ps). Changes in the PADs directly reflect the time-dependent separation and reorientation of the dissociating photofragments. (c)