Abstract
Photodissociation of propenal at 193nm was studied and the rotational states upto N=30 and K=3 and vibrational states (000), (010) and (001) of HCO X -2 A were detected. Small rotational excitation arose from repulsive part of the exit barrier and the geometry of the transition state. The results indicate the C 2 H 3 has 3.2 kcal/mol of translation and 42.5 kcal/mol of internal energy. Equally populated K α =1 doublet state and the two spinstates for the vibrational levels were detected. Relaxation was faster as compared to dissociation in the near UV region.