Dose-rate effects in the radiolysis of liquid n-hexane

Abstract

The radiolysis of liquid n-hexane has been studied over a wide range of dose-rates (4.7 × 10¹²–1.6 × 10²⁰ eV g^–1 sec^–1) and the yields of the intermediate molecular weight products (C_i), dodecane and hexene measured. The decrease in G(C_i) with decreasing dose-rate, expected of free radical behaviour, has been found, but there is a small “residual” yield of C_i products at the lowest dose-rate studied. This yield is further reduced when iodine (5 × 10^–3 M) is added to the hexane. The increase in G(dodecane) with decreasing dose-rate is less than the decrease in G (C_i) due to an overall change from primary to secondary radicals (in a structural sense), the resulting radicals producing hexene rather than dodecane. Analysis of the distribution of dodecane isomers leads to the relative yields of the three hexyl radicals and the variation of these with dose-rate can be followed.