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

Photodissociation of acrylonitrile has been studied at 157.6 nm through ana lysis of laser-induced fluorescence experiments. The CN(X (2)Sigma (+)) rad icals formed in this dissociation are detected in vibrational levels up to v=6 and rotational population distributions are measured for vibrational le vels 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 v inyl radical is the co-fragment. This is close to the 7% expected on the ba sis of the equipartition theorem which suggests that energy disposal is lar gely statistical. The vibrational and rotational distributions however are not in good agreement with an energy-conserving prior distribution suggesti ng that dynamical factors play a significant role in energy disposal. (C) 2 001 American Institute of Physics.