Free radicals by mass spectrometry. Part II. - The thermal decomposition of ethylene oxide, propyline oxide, dimethyl ether, and dioxane

The thermal decompositions of ethylene oxide, propylene oxide, dimethyl ether and dioxane in a stream of helium have been studied by means of a mass spectrometer designed to permit the measurement of free radical concentrations. With ethylene oxide it was found that each molecule decomposing gave rise to about 0.6 methyl radicals, and in propylene oxide the corresponding number had a lower limit of 0.36. Methyl radicals were also abundant in the decomposition of dimethyl ether. In the decomposition of dioxane only a small number of methyl radicals were found, and they probably come from a secondary reaction. No other radicals were detected, although formaldehyde was found to be a comparatively long-lived intermediate in the decomposition of dimethyl ether. The effect of the addition of nitric oxide on the decomposition of ethylene oxide was examined. Average values for the collision efficiency of the nitric oxide+methyl radical reaction at 950\ub0, and the methyl radical recombination reaction from 925\ub0 to 975\ub0 were found to be 2 7 10-4 and 2.5 7 10-2 respectively.Peer reviewed: YesNRC publication: Ye

General discussion

The Gerhard Herzberg fonds is held at the NRC Archives. Contact [email protected] for information about access.Le fonds Gerhard Herzberg est conserv\ue9 aux Archives du CNRC. Contactez [email protected] pour des informations sur l'acc\ue8s.Peer reviewed: YesNRC publication: Ye