ArF laser photodissociation dynamics of hydroxyacetone: LIF observation of OH and its reaction rate with the parent

Upon photoexcitation at 193 nm, hydroxyacetone dissociation appears to give CH3 and COCH2OH radicals as primary products, and the latter undergoes further dissociation to OH and ketene. Real time LIF observation of OH formation shows a dissociation rate of COCH2OH as (4.6±0.5)×106 s−1. There is no significant population (<1%) in excited vibrational levels of OH (X2Π) observed. The rotational state distribution has a Boltzmann temperature of the OH photofragment 380±40 K. Doppler spectroscopy shows an average translational energy with the OH photofragment as 3.6±1.3 kcal mol−1. The bimolecular rate constant for OH + hydroxyacetone is (2.8±0.2)×10−12 cm3 molecule−1 s−1.