Direct observation of OH formation from stabilised Criegee intermediates. Novelli, A., Vereecken, L., Lelieveld, J., & Harder, H. Physical chemistry chemical physics : PCCP, 16(37):19941-51, 10, 2014.
Direct observation of OH formation from stabilised Criegee intermediates. [pdf]Paper  Direct observation of OH formation from stabilised Criegee intermediates. [link]Website  abstract   bibtex   
The syn-CH3CHOO Criegee intermediate formed from the ozonolysis of propene and (E)-2-butene was detected via unimolecular decomposition and subsequent detection of OH radicals by a LIF-FAGE instrument. An observed time dependent OH concentration profile was analysed using a detailed model focusing on the speciated chemistry of Criegee intermediates based on the recent literature. The absolute OH concentration was found to depend on the steady state concentration of syn-CH3CHOO at the injection point while the time dependence of the OH concentration profile was influenced by the sum of the rates of unimolecular decomposition of syn-CH3CHOO and wall loss. By varying the most relevant parameters influencing the SCI chemistry in the model and based on the temporal OH concentration profile, the unimolecular decomposition rate k (293 K) of syn-CH3CHOO was shown to lie within the range 3-30 s(-1), where a value of 20 ± 10 s(-1) yields the best agreement with the CI chemistry literature.

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