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 b y probing the nascent photoproduct OH using LIF spectroscopy. The photoprod uct OH is formed mainly in the ground vibrational state with a rotational e nergy of 1.6 +/- 0.2 kcal/mol The energy partitioned as photofragment trans lational energy is 10.0(-2.8)(+5.0) kcal/mol. The present study in combinat ion with the available dynamic information implies that the C-O single bond fission is the dominant OH-producing reaction. The modeling of the observe d energy partitioning indicates that about 80% of the excess energy above t he barrier is retained in the C=O moiety. (C) 2001 Elsevier Science B.V. Al l rights reserved.