DISSOCATION DYNAMICS OF PHOTOCHEMICALLY ACTIVATED 3,5-CYCLOHEPTADIENONE IN THE GAS PHASE.

Article abstract of DOI:10.1021/ja00332a007

Energy partitioning in the photoactivated fragmentation of 3,5-cycloheptadienone has been studied by using time resolved laser absorption spectroscopy. We have directly measured the CO product vibrational energy distribution and find that for excitation at 193 nm, N//0:N//1:N//2 equals 1. 00:0. 33:0. 09. Excitation at 249 nm yields N//0:N//1:N//2 equals 100:0. 24:0. 04, and excitation aT 308 nm yields N//0:N//1:N//2 equals 1. 00:0. 14:0. 02. The data at each excitation wavelength are consistent with a statistical model for energy disposal if the full reaction exoergicity is available to be randomly distributed among all the developing products' degrees of freedom. This suggests the products are strongly coupled well into the exit channel. These observations are contrasted with results on energy disposal for an apparently similar reaction, the dissociation of 3-cyclopentenone, where it was found that the full reaction exoergicity was not available to the products' vibrational modes.