Dynamics of NO produced by photodissociation of t-butyl nitrite on Ag(111)

The dynamics of NO ejected by the 248 nm photodissociation of t-butyl nitrite, (CH3)3CONO, adsorbed on Ag(111) has been examined. A trimodal NO velocity distribution is observed. The velocity distribution varies with the detection angle and coverage and is consistent with a model in which direct excitation of t-butyl nitrite is followed by prompt dissociation to form nitric oxide which desorbs along one of three distinguishable trajectories involving: (1) no intervening capture or collisions, (2) one or a few intervening collisions without complete thermalization, and (3) equilibration with the substrate temperature.