ISSN:
0538-8066
Schlagwort(e):
Chemistry
;
Physical Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Rate constants for the low-pressure unimolecular decomposition of ONBr and ONCl in an argon bath have been determined at temperatures in the vicinity of 1000°K. Both molecules exhibit the usual depression of the observed activation energy below the bond dissociation energy. The Arrhenius expressions obtained are (units of cc mole-1 sec-1): \documentclass{article}\pagestyle{empty}\begin{document}$$ ONBr - Ar:\log k = (15.06 \pm 0.27) - (25.06 \pm 1.13)kcalmole^{ - 1} /\theta $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ ONCl - Ar:\log k = (15.95 \pm 0.52) - (43.79 \pm 2.04)kcalmole^{ - 1} /\theta $$\end{document} Treatment of the data by the classical RRK theory yields s ≅ 2.7 ± 1 for ONCl and 3.0 ± 0.6 for ONBr. Coupling the shock tube results for ONCl with lower-temperature data from Ashmore and Burnett [3], one obtains s ≅ 2.5 ± 0.5 and λ ≍ 1. If it is assumed that s is also 2.5 for ONBr, then one finds the surprising (but tentative) result that λONCl—Ar/λONBr—Ar ≍ 3 to 4.
Zusätzliches Material:
7 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/kin.550050611
