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 ³π_u(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.