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 Torr) 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: k1=(1.3±0.9)×10−13 exp(1600±200)/Tcm3 molecule−1 s−1 and k2=(1.1±0.5)×10−11 exp(470±135)/Tcm3 molecule−1 s−1. At room temperature and 1 Torr, 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.