PHOTODISSOCIATION OF ACRYLIC-ACID AT 193 NM

This paper describes the photolysis of acrylic acid (H2C=CHCOOH) monom ers upon pi-->pi excitation at 193 nm. The photofragment velocity dis tribution measurements indicate that only primary C-C and C-O bond fis sions are major photodissociation pathways; molecular decarboxylation and decarbonylation reactions do not occur to a significant extent. Th ere are two different primary C-C bond fission channels resulting in t he production of HOCO radicals in the ground and first electronically excited states. We also determine an upper Limit on the C-C bond stren gth of about 100 kcal/mol; this agrees with the value we calculate fro m literature heats of formation but is considerably less than that ass umed by previous workers.