Theoretical Structures and Stabilities of C3H5+ and C3H2F3+ Cations

Michael McAllister, Thomas T. Tidwell, Michael R. Peterson, Imre G. Csizmadia

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The structures and energies of C3H2F3+ isomers have been calculated, and at the MP4(SDQ)/6-31G// HF/6-31G + ZPVE level fluorine migration converting CH2=C+CF3 (3) to the allylic cation CH2=CFCF2+ (4) is exothermic by 31.5 kcal/mol, with a barrier involving a bridged fluoronium ion of only 6.1 kcal/mol. Rearrangement of 3 to CHF=CHCF2+ (16) is exothermic by 44.9 kcal/mol and occurs by a multistep process including a 1, 3-fluorine migration with no barrier higher than 0.3 kcal/mol. Comparative studies of C3H6+ are also reported. It is concluded that 3 is a good candidate for an experimental search for fluorine migration in carbocations.

Original languageEnglish
Pages (from-to)575-580
Number of pages6
JournalJournal of Organic Chemistry
Issue number2
Publication statusPublished - Jan 1 1991


ASJC Scopus subject areas

  • Organic Chemistry

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