title: Enols are common intermediates in hydrocarbon oxidation.
abstract: Models for chemical mechanisms of hydrocarbon oxidation rely on spectrometric identification of molecular structures in flames. Carbonyl (keto) compounds are well-established combustion intermediates. However, their less-stable enol tautomers, bearing OH groups adjacent to carbon-carbon double bonds, are not included in standard models. We observed substantial quantities of two-, three-, and four-carbon enols by photoionization mass spectrometry of flames burning representative compounds from modern fuel blends. Concentration profiles demonstrate that enol flame chemistry cannot be accounted for purely by keto-enol tautomerization. Currently accepted hydrocarbon oxidation mechanisms will likely require revision to explain the formation and reactivity of these unexpected compounds.
authors.affiliation: Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, CA 94551-0969, USA. cataatj@sandia.gov
authors.forename: Craig A
authors.initials: CA
authors.lastname: Taatjes
authors.forename: Nils
authors.initials: N
authors.lastname: Hansen
authors.forename: Andrew
authors.initials: A
authors.lastname: McIlroy
authors.forename: James A
authors.initials: JA
authors.lastname: Miller
authors.forename: Juan P
authors.initials: JP
authors.lastname: Senosiain
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Klippenstein
authors.forename: Fei
authors.initials: F
authors.lastname: Qi
authors.forename: Liusi
authors.initials: L
authors.lastname: Sheng
authors.forename: Yunwu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Terrill A
authors.initials: TA
authors.lastname: Cool
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Westmoreland
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Law
authors.forename: Tina
authors.initials: T
authors.lastname: Kasper
authors.forename: Katharina
authors.initials: K
authors.lastname: Kohse-Höinghaus