Determination of the rapid energy redistribution in a transition state by using molecular rotation as a clock and translational energy release as an energy monitor: The photodissociation of iodobenzene

Abstract

State‐selective photofragment translational spectroscopy is used to determine the spatial and velocity distributions of the ground state iodine atoms produced from the photodissociation of iodobenzene at 304.67 nm. In addition to an alkyl iodide type fast dissociation, a slow dissociation was observed. From the observed velocity dependence of the spatial anisotropy of the latter dissociation and the theoreticaldissociation time dependence of the spatial anisotropy obtained from the rotational correlation function, we were able to determine the rate of energy redistribution to the phenyl ring modes during the dissociation process.