Molecular beam studies of the photolysis of allene and the secondary photodissociation of the C3Hx 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+C3H3 and the H2+C3H2 channels. The quantum yields for these first steps are 0.89 and 0.11, respectively. Subsequent photolysis of the C3H3 radical produces H2+C3H, C3H2+H, and C2H2+CH, while the C3H2 produces C3+H2, C2H+CH, and C2H2+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.