Dynamics of acetic acid dissociation at 193.3 nm: selectivity in OH reaction channel

The photodissociation dynamics of acetic acid at 193.3 nm is investigated by probing the nascent photoproduct OH using LIF spectroscopy. The photoproduct OH is formed mainly in the ground vibrational state with a rotational energy of 1.6±0.2 kcal/mol. The energy partitioned as photofragment translational energy is 10.0−2.8+5.0 kcal/mol. The present study in combination with the available dynamic information implies that the C–O single bond fission is the dominant OH-producing reaction. The modeling of the observed energy partitioning indicates that about 80% of the excess energy above the barrier is retained in the CO moiety.