title: Observation of a large negative temperature dependence for rate coefficients of reactions of OH with oxygenated volatile organic compounds studied at 86-112 K.
abstract: The rate coefficients (k) for reactions of OH with acetone, methyl ethyl ketone (MEK) and dimethyl ether (DME) have been measured in the temperature range 86-112 K using a pulsed Laval nozzle apparatus. Large increases in k at lower temperatures were observed, with k(86K)/k(295K) = 334 for acetone, and k(93K)/k(295K) = 72 and 3, for MEK and DME respectively. A mechanism involving the formation of a hydrogen bonded complex prior to an overall barrier on the potential energy surface is proposed to explain this behaviour.
authors.affiliation: School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Shannon
authors.forename: Sally
authors.initials: S
authors.lastname: Taylor
authors.forename: Andrew
authors.initials: A
authors.lastname: Goddard
authors.forename: Mark A
authors.initials: MA
authors.lastname: Blitz
authors.forename: Dwayne E
authors.initials: DE
authors.lastname: Heard