Kinetic Study of Gas-Phase Reactions of OH and NO3Radicals and O3with iso-Butyl andtert-Butyl Vinyl Ethers

Abstract

Using a relative rate technique, kinetic studies on the gas-phase reactions of OH radicals, ozone, and NO(3) radicals with iso-butyl vinyl ether (iBVE) and tert-butyl vinyl ether (tBVE) have been performed in a 405 L Duran glass chamber at (298 ± 3) K and atmospheric pressure (750 ± 10 Torr) in synthetic air using in situ FTIR spectroscopy to monitor the reactants. The following rate coefficients (in units of cm(3) molecule(-1) s(-1)) have been obtained: (1.08 ± 0.23) × 10(-10) and (1.25 ± 0.32) × 10(-10) for the reactions of OH with iBVE and tBVE, respectively; (2.85 ± 0.62) × 10(-16) and (5.30 ± 1.07) × 10(-16) for the ozonolysis of iBVE and tBVE, respectively; and (1.99 ± 0.56) × 10(-12) and (4.81 ± 1.01) × 10(-12) for the reactions of NO(3) with iBVE and tBVE, respectively. The rate coefficients for the NO(3) reactions are first-time determinations. The measured rate coefficients are compared with estimates using current structure activity relationship (SAR) methods and the effects of the alkoxy group on the gas-phase reactivity of the alkyl vinyl ethers toward the oxidants are compared and discussed. In addition, estimates of the tropospheric lifetimes of iBVE and tBVE with respect to their reactions with OH, ozone, and NO(3) for typical OH radical, ozone, and NO(3) radical concentrations are made, and their relevance for the environmental fate of compounds is considered.