ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The gas-phase equilibrium and rate constants for the isomerizations of 1,3,6-cyclooctatriene (136COT) to 1,3,5-cyclooctatriene (135COT) [reaction (1)] and bicyclo[4.2.0]octa-2,4-diene (BCO) to 135COT [reaction (-2)] have been measured between 390 and 490 K and between 330 and 475 K, respectively. The rate constant of reaction (1) obeys the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$$k_{\rm 1} = 10^{10.93 \pm 0.08} {\rm exp}[- (115.9 \pm 0.7{\rm kJ}/{\rm mol})/RT]{\rm s}^{ - 1}$$\end{document} The corresponding equilibrium constant is given by the van′t Hoff equation \documentclass{article}\pagestyle{empty}\begin{document}$${\rm In K}_{\rm 1}^{\rm 0} = (0.24 \pm 0.04) + (13.78 \pm 0.15{\rm kJ}/{\rm mol})/RT$$\end{document} The strain energy of the 136COT ring is calculated to be 31.7 kJ/mol, based on the known value of 37.2 kJ/mol for 135COT, and ΔHf0(298 K) for gaseous 136COT is 196.3 kJ/mol. The rate constant of reaction (-2) obeys the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$$k_{{\rm - 2}} = 10^{12.38 \pm 0.23} {\rm exp}[(- 106.9 \pm 1.5{\rm kJ}/{\rm mol})/RT]{\rm s}^{ - 1}$$\end{document} The equilibrium constant for 135COT ⇆ BCO fits the van′t Hoff equation \documentclass{article}\pagestyle{empty}\begin{document}$${\rm In K}_{\rm 2}^{\rm 0} = (- 1.20 \pm 0.02) - (0.40 \pm 0.07{\rm kJ}/{\rm mol})/RT$$\end{document} The strain energy of the BCO skeleton is calculated to be 108.3 kJ/mol, and ΔHf0(298 K) for gaseous BCO is 183.3 kJ/mol.
Additional Material:
5 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550151011
Permalink
