Rate constants for the reaction of OH radicals with n-propyl, n-butyl, iso-butyl and tert-butyl vinyl ethers

Abstract

Rate constants for the reaction of OH radicals with n-propyl vinyl ether (PVE, CH 3CH 2CH 2OCH CH 2), n-butyl vinyl ether (BVE, CH 3CH 2CH 2CH 2OCH CH 2), iso-butyl vinyl ether (IBVE, (CH 3) 2CHCH 2OCH CH 2) and tert-butyl vinyl ether (TBVE, (CH 3) 3COCH CH 2), have been measured in the temperature and pressure ranges 232–373 K and 30–300 Torr using the pulsed laser photolysis-laser-induced fluorescence method, and at 298 K and 760 Torr using the relative method. The obtained results are k 1=(9.3±0.6)×10 −12 exp[(708±20)/ T], k 2=(1.5±0.2)×10 −11 exp[(572±42)/ T], k 3=(1.6±0.1)×10 −11 exp[(567±20)/ T], k 4=(1.7±0.2)×10 −11 exp[(549±25)/ T] cm 3 molecule −1 s −1. The values at 298 K are k 1=(1.0±0.1)×10 −10, k 2=(1.0±0.1)×10 −10, k 3=(1.1±0.1)×10 −10, k 4=(1.1±0.1)×10 −10 cm 3 molecule −1 s −1. The deduced tropospheric lifetimes of these ethers for reaction with OH are of the order of 1 h and they are comparable to those for reaction with ozone.