Promotion by SF6 of a Radiolytically Induced Chain Reaction for the Geometrical Isomerization of cis or trans-Butene-2 in Dilute Gaseous Mixtures
FOR several years SF6 has been used in radiolytic studies because of its high cross-section for capture of low-energy electrons and consequent effect on observable products resulting from positive-ion neutralization reactions. A reduced yield of H2 from irradiated propane has been reported1 and attributed to electron scavenging by the small proportions of SF6 present. On the other hand, SF6 does not affect the H2 yield from irradiated liquid unsaturates such as trans-butene-2 (ref. 2), indicating that ionic species may not be important with respect to H2 formation from these olefines.
SF6 added to irradiated gaseous ethylene acts not only as an electron scavenger
Abstract The reduction in the yields of C 4 unsaturated hydrocarbons from C 2 H 4 NH 3 mixtures in the presence of SF 6 is due to secondary processes involving a radical derived from SF 6 .
Nitrous Oxide as an Electron Scavenger in the Radiolysis of Hydrocarbons
Nitrous oxide has been used as an electron scavenger in the radiolysis of hydrocarbons: cyclohexane, cyclohexene, benzene, and their mixtures. Considering that the energy for the formation of an ion pair is about 25 eV. in hydrocarbons, 0.4mol.1−1 of nitrous oxide is not enough to capture all the electrons ejected from irradiated hydrocarbons. In the case of cyclohexane, 70% of the ejected electrons seem to be captured by 0.4mol.1−1 of nitrous oxide. In the case of benzene, G(N2) is about a half of that for cyclohexane. This has been explained tentatively in terms of the ability of benzene to capture electrons. The G(N2)’s in the cases of cyclohexene and benzene have not shown any noticeable dependence on the concentration of nitrous oxide. This shows that hydrogen does not result from the neutralization in these systems. In order to clarify them, the primary processes in the radiolysis of cyclohexane have been further considered using the data previously obtained.