Nitrous Oxide as an Electron Scavenger in the Radiolysis of Hydrocarbons

Abstract

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.

γ-Radiolysis of cyclohexane with electron scavengers. IV. CO2 as an electron scavenger

“…As reaction [5] is endothermic by more than 3.6 eV in the gas phase (13,14), this is not surprising. The C02-ion will eventually be neutralized by a hydrocarbon cation.…”

“…Yields of nitrogen which are larger than the normally accepted value of G(e-) are obtained from the liquid phase radiolysis of the cyclohexane-N20 system (3)(4)(5)(6). The origin of this extra nitrogen yield is uncertain, although the suggestion has been made that reaction [3] is responsible (1,5).…”

“…The origin of this extra nitrogen yield is uncertain, although the suggestion has been made that reaction [3] is responsible (1,5). Yields of the major liquid products, bicyclohexyl and cyclohexene, are larger than when N 2 0 is absent (4 The experimental procedures and sources of N20 and Albrecht using electron s~i n resonance precursors when neutralized (4).…”

Secondary reactions in the γ-radiolysis of hydrocarbons with electron scavengers

“…Thus the large extra yield of N2 is difficult t o explain. Perhaps it arises from a small amount of chain decomposition of N20, especially since the nitrogen yields seem to vary considerably from laboratory to laboratory (4,6,7). Our metal cells could possibly catalyze such a decomposition to a greater extent than the glass cells used by others.…”

“…In an earlier study of the radiolysis of liquid cyclohexane in the presence of N 2 0 , Sato et al (4) noted an increase in cyclohexene yield. I t therefore seemed appropriate to make a more complete study of the yield of the major liquid products as a function of dose and coverage, and to study the SF6-cyclohexane system as well.…”