1,2-Pentadiene Decomposition

Published

November 1, 2001

Author(s)

J Herzler, Jeffrey A. Manion, Wing Tsang

Abstract

1,2-Pentadiene has been decomposed in single pulse shock tube experiments. There appear to be a large number of parallel decomposition and isomerization channels. The following rate expressions for isomerization in the temperature range 1100 K-1250 K and 2 bar pressure have been obtainedk(1,2-pentadiene {arrow} 1- pentyne) = 1x10¹³exp(-32700 900K/T) s^-1^k(1,2-pentadiene {arrow} 1,3-pentadiene(cis & trans)) = 1.1x10¹⁴exp(-33290 900K/T) s^-1k(1,2-pentadiene {arrow} cyclopentene) = 1.2x10¹¹exp(-25755 900 K/T) s^-1^From detailed balance the rate expression for 1,3 to 1,2-pentadiene isomerization has been found to bek(1,3-pentadiene {arrow} 1,2-pentadiene) = 8x10¹⁴exp(-42183 900 K/T) s^-1The significance of the 1,3 to 1,2 isomerization process as a bridge between the two carbon and three carbon species in high temperature hydrocarbon decomposition systems is discussed.The decomposition processes involve bond breaking and retroene reactions. The rate expression for the latter has been found to bek(1,2-pentadiene {arrow} propyne + ethylene) = 6x10¹² exp(-28000 900 K/T)s^-1.The rate constants for the breaking of the C₃-C₄ and C₄-C₅ bonds appear to be close to each other. The resonance energy for the 1,3-butadien-2-yl radical is smaller than that for allyl by an amount that is equal to the extra stabilization in butadiene.

Citation

International Journal of Chemical Kinetics

Volume

33

Issue

No. 11

Pub Type

Journals

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Keywords

1, 2-pentadiene, decomposition, isomerization, kinetics, single pulse shock tube, unimolecular reactions

Citation

Herzler, J. , Manion, J. and Tsang, W. (2001), 1,2-Pentadiene Decomposition, International Journal of Chemical Kinetics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=832043 (Accessed December 12, 2024)