Photofragmentation of Ketene to CH2((Tilde X)3B1) + CO: Dissociation Rate, Energy Release and Exit Barrier Height.

摘要

Ketene cooled in a supersonic free jet is photolyzed in the ultraviolet range. The appearance rate of fragment CO from triplet ketene as a function of ultraviolet photon energy is measured by vacuum ultraviolet laser-induced fluorescence. A tunneling-corrected RRKM theory is used to fit the observed dissociation rate of ketene using the ab initio vibrational frequencies of the transition state. The rotational state distributions of CO from ketene photolyzed at 1120, 190, and 30 cm(sup (minus)1) above and at 50 cm(sup (minus)1) below the top of the barrier to dissociation on the triplet surface are measured. 25 refs., 17 figs., 9 tabs.