Photodissociation dynamics of dicyclopropyl ketone at 193 nm: Isomerization of the cyclopropyl ligand

The dissociation dynamics of dicyclopropyl ketone excited in the (S₂←S₀) band at λ=193 nm was studied. Experimental results from two complementary techniques determine the identity of the products and measure their translational and internal energies. Electronic structure calculations were employed to define stationary points on the relevant potential energy surfaces and phase-space theory calculations to predict product state distributions. Based on the results, a dissociation mechanism for DCPK in which isomerization occurs before fragmentation, leading to the formation of allyl as the principal isomer of the C₃H₅ radical was proposed.