Energy disposal in CN(X 2Σ+) produced in the 157 nm photodissociation of acrylonitrile

Abstract

Photodissociation of acrylonitrile has been studied at 157.6 nm through analysis of laser-induced fluorescence experiments. The CN(X 2Σ+) radicals formed in this dissociation are detected in vibrational levels up to v=6 and rotational population distributions are measured for vibrational levels v=0–3. The average energies found in vibration and rotation of CN are approximately equal and represent about 5% of the available energy if the vinyl radical is the co-fragment. This is close to the 7% expected on the basis of the equipartition theorem which suggests that energy disposal is largely statistical. The vibrational and rotational distributions however are not in good agreement with an energy-conserving prior distribution suggesting that dynamical factors play a significant role in energy disposal.