Detection of a Criegee Intermediate with an Unsaturated Hydrocarbon Substituent: Fourier-Transform Microwave Spectroscopy of Methyl Vinyl Ketone Oxide

Yasuki Endo*, Henryk Arnold Witek, Chen An Chung, Yuan-Pern Lee

*Corresponding author for this work

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Pure rotational transitions of methyl vinyl ketone oxide, or the so called methyl-vinyl Criegee intermediate, were observed by Fourier-transform microwave spectroscopy. Among the four possible conformers of this species, predicted by theory within an energy window of 3 kcal/mol, only the lowest-energy conformer, the syn-trans form, was detected in a discharged jet of a 1,3-diiode-but-2-ene (either in Z- or E-conformation) and O-2 mixture diluted in Ar. Thirty pure rotational transitions with internal rotation splitting of the methyl top were observed. The observed frequencies were analyzed by the XIAM program, yielding an internal rotation barrier of 702.8(28) cm(-1), which reasonably agrees with a theoretical value of 680 cm(-1) determined with CCSD(T)/cc-pVTZ.

Original languageEnglish
Pages (from-to)6203-6206
Number of pages4
JournalJournal of Physical Chemistry A
Issue number30
StatePublished - 30 Jul 2020



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