Temperature-Dependence of the Rates of Reaction of Trifluoroacetic Acid with Criegee Intermediates.

ABSTRACT: The rate coefficients for gas-phase reaction of trifluoroacetic acid (TFA) with two Criegee intermediates, formaldehyde oxide and acetone oxide, decrease with increasing temperature in the range 240-340 K. The rate coefficients k(CH₂ OO + CF₃ COOH)=(3.4±0.3)×10^-10  cm³  s^-1 and k((CH₃ )₂ COO + CF₃ COOH)=(6.1±0.2)×10^-10  cm³  s^-1 at 294 K exceed estimates for collision-limited values, suggesting rate enhancement by capture mechanisms because of the large permanent dipole moments of the two reactants. The observed temperature dependence is attributed to competitive stabilization of a pre-reactive complex. Fits to a model incorporating this complex formation give k [cm

SUBMITTER: Chhantyal-Pun R 

PROVIDER: S-EPMC5575497 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature