Infrared Multiphoton Dissociation in Two-Channel Systems. Pulse-Duration Effects

Article abstract of DOI:10.1021/j100390a009

Both ethyl vinyl ether (EVE) and dihydrofuran (DHF) dissociate by two reaction channels which differ by ca. 25 kcal mol^-1 in activation energies.In DHF, the branching ratio between these channels produced by IR-multiphoton-induced dissociation shows no power dependence, by contrast to previous work with EVE.In view of the similarity of the Arrhenius activation parameters in the two systems, this is surprising.Therefore, a comparison of peak-power dependence of the branching ratio in the two systems has been studied at hν_CO2 = 1076 cm^-1 where the average energy absorbed is the same in both molecules.Results on the power dependence of branching ratio and yield suggest that differences in absorption coefficients (pumping rates) in the quasicontinuum may account for the differences in power dependence.