Observation of a large negative temperature dependence for rate coefficients of reactions of OH with oxygenated volatile organic compounds studied at 86-112 K.
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.
Shannon
Robin J
RJ
School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
Taylor
Sally
S
Goddard
Andrew
A
Blitz
Mark A
MA
Heard
Dwayne E
DE