Activation parameters for the additions of arylhalocarbenes to alkenes

Robert A. Moss, Witold Ławrynowicz, Nicholas J. Turro, Ian Gould, Yuan Cha

Research output: Contribution to journalArticle

65 Citations (Scopus)

Abstract

By use of nanosecond laser flash photolytic methods, absolute rate constants have been obtained for the additions of p-(trifluoromethyl)phenylbromocarbene (CF3C6H4CBr), phenylbromocarbene (PhCBr), phenylchlorocarbene (PhCCl), phenylfluorocarbene (PhCF), and p-methoxyphenylfluorocarbene (CH3OC6H4CF) to tetramethylethylene (TME) and 1-hexene. The rate constants ranged from 1.7 × 109 (CF3C6H4CBr/TME) to 5.0 × 104 L/(M·s) (CH3OC6H4CF/1-hexene); classical structure/reactivity relations were obeyed. Determination of the rate constants at temperatures between 315 and 200 K gave Ea, log A, ΔH, ΔS, and ΔG for the 10 reactions. All of the reactions were dominated by ΔS. ΔG ranged from 5.0 to 11 kcal/mol for the fastest and slowest reactions. Negative values of Ea were observed for some of the faster reactions at higher temperatures. These results are analyzed in terms of single-step addition reactions where ΔG is dominated by ΔS and, alternatively, in terms of a two-step mechanism proceeding through a carbene-alkene complex.

Original languageEnglish (US)
Pages (from-to)7028-7032
Number of pages5
JournalJournal of the American Chemical Society
Volume108
Issue number22
StatePublished - 1986
Externally publishedYes

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Alkenes
Olefins
Rate constants
Chemical activation
Temperature
Addition reactions
Lasers
1-hexene
2,3-dimethyl-2-butene
carbene

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Moss, R. A., Ławrynowicz, W., Turro, N. J., Gould, I., & Cha, Y. (1986). Activation parameters for the additions of arylhalocarbenes to alkenes. Journal of the American Chemical Society, 108(22), 7028-7032.

Activation parameters for the additions of arylhalocarbenes to alkenes. / Moss, Robert A.; Ławrynowicz, Witold; Turro, Nicholas J.; Gould, Ian; Cha, Yuan.

In: Journal of the American Chemical Society, Vol. 108, No. 22, 1986, p. 7028-7032.

Research output: Contribution to journalArticle

Moss, RA, Ławrynowicz, W, Turro, NJ, Gould, I & Cha, Y 1986, 'Activation parameters for the additions of arylhalocarbenes to alkenes', Journal of the American Chemical Society, vol. 108, no. 22, pp. 7028-7032.
Moss, Robert A. ; Ławrynowicz, Witold ; Turro, Nicholas J. ; Gould, Ian ; Cha, Yuan. / Activation parameters for the additions of arylhalocarbenes to alkenes. In: Journal of the American Chemical Society. 1986 ; Vol. 108, No. 22. pp. 7028-7032.
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