ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The gas-phase decomposition of n-heptyl-1 and n-heptyl-2 hydroperoxides C7H15OOH, which split into two radicals C7H15O and OH, has been investigated in the temperature range of 250-360°C. The decomposition has been carried out in a hydrogen-oxygen mixture (the hydroperoxide represents about 50 ppm) so as to avoid secondary reactions between the formed radicals and the reactants. Although the H2-O2 mixture is not spontaneously reactive in our conditions, it operates the transformation, through a fast and well-known process, of the OH radicals into HO2 radicals and then into H2O2. However, C7H15O radicals are also transformed into HO2 radicals and then into H2O2, but through an unknown process. To avoid heterogeneous reactions, vessel and probe are coated by B2O3 and then treated by the slow combustion of hydrogen at 510°C and 250 torr before the experiments are performed. As the reaction scheme is very simple, due to the use of the H2-O2 mixture, the determination of the evolutions of the HO2 concentration (followed by electronic paramagnetic resonance) lead to the determination of the gas-phase decomposition rate constant of hydroperoxides. For the n-heptyl-1 hydroperoxide the rate constant is \documentclass{article}\pagestyle{empty}\begin{document}$$(1.1 \pm 0.25) \times 10^{16} \exp - \left({\frac{{43,500 \pm 1000}}{{RT}}} \right){\rm s}^{{\rm - 1}}$$\end{document} and for the n-heptyl-2 hydroperoxide it is \documentclass{article}\pagestyle{empty}\begin{document}$$(7 \pm 2) \times 10^{15} \exp - \left({\frac{{41,500 \pm 1000}}{{RT}}} \right){\rm s}^{{\rm - 1}}$$\end{document}.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550141205
Permalink
