Low-pressure study of the reactions of Cl atoms with acrylic acid and allyl alcohol

The kinetics of the gas-phase reactions of chlorine atoms with acrylic acid (1) and allyl alcohol (2) have been investigated at low pressure (0.5-3 Tort) in the temperature range 260-333 K using the mass spectrometric discharge-flow method. The temperature dependence of the reaction rate constants at 1 Torr have been determined under pseudo-first-order conditions in excess of organic compound over Cl atoms, giving: k(1) = (1.3+/-0.9) x 10(-13) exp(1600+/-200)/T cm(3) molecule(-1) s(-1) and k(2) = (1.1+/-0.5) x 10(-11) exp(470+/-135)/T cm(3) molecule(-1) s(-1). At room temperature and I Tort, products of abstraction and addition channels have been detected for reactions (1) and (2). By mass spectrometric quantification, the branching ratio for channels giving HCl, was determined as 0.13+/-0.05 for reaction (1) and 0.57+/-0.06 for reaction (2). The results obtained are related to previous studies, and the atmospheric implications are also discussed in relation to the homogeneous sinks of acrylic acid and allyl alcohol. (C) 2003 Elsevier Ltd. All rights reserved.