Molecular beam studies of the photolysis of allene and the secondary photodissociation of the C sub 3 H sub x fragments

Angle resolved time of flight (TOF) measurements of the fragments produced when allene is photolyzed at 193 nm are described. The two primary processes that have been identified from these measurements are the H+C{sub 3}H{sub 3} and the H{sub 2}+C{sub 3}H{sub 2} channels. The quantum yields for these first steps are 0.89 and 0.11, respectively. Subsequent photolysis of the C{sub 3}H{sub 3} radical produces H{sub 2}+C{sub 3}H, C{sub 3}H{sub 2}+H, and C{sub 2}H{sub 2}+CH, while the C{sub 3}H{sub 2} produces C{sub 3}+H{sub 2}, C{sub 2}H+CH, and C{sub 2}H{sub 2}+C. The translational energy distributions for each one of these steps have been derived using the forward convolution technique. These energy distributions reveal the exit barriers and other constraints on the potential energy surfaces that lead to the above stated products.