PHOTODISSOCIATION OF ACRYLONITRILE AT 193 NM - A PHOTOFRAGMENT TRANSLATIONAL SPECTROSCOPY STUDY USING SYNCHROTRON-RADIATION FOR PRODUCT PHOTOIONIZATION

We have investigated the photodissociation of acrylonitrile (H2CCHCN) at 193 nm using the technique of photofragment translational spectrosc opy. The experiments were performed at the Chemical Dynamics Beamline at the Advanced Light Source and used tunable vacuum ultraviolet synch rotron radiation for product photoionization, We have identified four primary dissociation channels including atomic and molecular hydrogen elimination, HCN elimination, and CN elimination. There is significant evidence that all of the dissociation channels occur on the ground el ectronic surface following internal conversion from the initially opti cally prepared state. The product translational energy distributions r eflect near statistical simple bond rupture for the radical dissociati on channels, while substantial recombination barriers mediate the tran slational energy release for the two molecular elimination channels. P hotoionization onsets have provided additional insight into the chemic al identities of the products and their internal energy content, (C) 1 998 American Institute of Physics.