ION IMAGING OF THE PHOTODISSOCIATION OF CHLORINE-CONTAINING MOLECULES

The photodissociation dynamics of four chlorine-containing compounds w as studied by the ion imaging technique. Two compounds, ClNO and (CH3) (3)COCl, exhibited strong anisotropy, and the kinetic energy distribut ions for Cl(P-2(3/2)) and Cl(2P(1/2)) were indistinguishable. For CCl 4 and SOCl2 the kinetic energy distributions of Cl and Cl were very d ifferent. In all cases most of the chlorine atoms were released in the ir ground P-2(3/2) state. A general explanation is given based on thes e data and those of others. The process is described in terms of three states whose energies are in the following order: the ground state, a state correlating with Cl, and a state correlating with Cl. Sooner o r later the Cl state must cross the Cl state. If the crossing is soon er, i.e. in the Franck-Condon region, Cl and Cl will have different t ranslational energy distributions. If the crossing is later, i.e. at l ong distances, Cl and Cl will have descended a repulsive surface and reached their asymptotic and nearly equal kinetic energies.