Optical time of flight spectroscopy: A method for the direct state selective measurement of photofragment recoil energies

Abstract

The ir photolysis of C2H3CN, producing C2[a 3πu(v=0)] via sequential photodissociation processes, is studied using laser induced fluorescence to measure the time of flight spectrum of the recoiling C2 photofragments. This technique measures the recoil velocity distribution for particular energy states, and can be applied to the study of a number of elementary processes. The average recoil energy of the C2 photofragment is 1.1±0.3 kcal/mole, and this includes contributions from recoil along the reaction coordinate as well as rotational motion in the precursor.