Radiolysis of 1,1-difluoroethane

Abstract

1,1-Difluoroethane has been irradiated in the gas phase both in the presence and absence of NO, and those products eluting from a Porapak Q column before 1,1-difluoroethane were identified and measured. Hydrogen is formed by at least two processes. Trifluoromethane and 1,1,1 -trifluoroethane are formed by fluoride ion transfer reactions of fragment ions. Methane and ethane are formed from methyl radicals resulting from fragmentation of the parent ion. Ethene, fluoroethene, and 1,1-difluoroethene are all formed in significant amounts. In the absence of radical scavengers all unsaturated products reach limiting concentrations of less than 100 ppm.

Radiation‐induced hydrogen fluoride formation in fluorine‐containing ethanes and ethenes

“…We have no explanation for the lower H f yields from 1,l-difluoroethane in comparison to the yields reported by Carmichael and Lau [27]. Our analytical procedure has generally yielded results which were in good agreement with published data.…”

“…Recent investigations [27] on the radiolysis of 1,l-difluoroethane have shown that some of the products (HF was not analyzed) must be formed via ionmolecule reactions even a t pressures above 100 torr. In this series of experiments excited fluoroethane molecules were formed by secondary electrons which were released from the glass walls of the sample vessel through gamma ray interaction.…”

Chemistry of Nuclear Recoil 18F-Atoms in Gaseous Fluoroethanes Using the 19F (ρ, pn)18F Reaction

“…Because of the low yields the effect of H 2 S is not very clear but for some of the ethenes (CF 18 F=CF 2 in CF 3 -CF 3 at 1.7 χ 10 4 Pa and E-and Z-C ,8 FH=CHF in CF 2 H-CFH 2 ) the yields are increasing with increasing H 2 S concentration. The increase in these yields is probably a result of a protection of the ethenes by H 2 S against species generated by radiolysis; a similar effect has been found for ethenes in the radiolysis of 1,1-difluoroethane [36]. The increase or constancy of the yields of the ethenes with increasing H 2 S-concentration indicates that these products are formed (mainly) through a concerted HF-elimination reaction, as addition of H 2 S would otherwise lead to a decrease in the yields.…”