Enols are common intermediates in hydrocarbon oxidation.
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.
Taatjes
Craig A
CA
Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, CA 94551-0969, USA. cataatj@sandia.gov
Hansen
Nils
N
McIlroy
Andrew
A
Miller
James A
JA
Senosiain
Juan P
JP
Klippenstein
Stephen J
SJ
Qi
Fei
F
Sheng
Liusi
L
Zhang
Yunwu
Y
Cool
Terrill A
TA
Wang
Juan
J
Westmoreland
Phillip R
PR
Law
Matthew E
ME
Kasper
Tina
T
Kohse-Höinghaus
Katharina
K