Radiolysis of 2, 2'-Azo-bis-isobutyronitrile in Benzene Solution, (I)Energy Transfer in Benzene

摘要

Nitrogen is formed by the γ-radiolysis of 2, 2'-azo-bis-isobutyronitrile (AIBN) in benzene solution. The 100 eV yield of nitrogen G(N2) is observed to be 1.4 at its assymptotic value attained above 0.02 M AIBN. This and other results are interpreted in terms of energy transfer from excited benzene to AIBN. Experiments using cyclohexene as a selective quencher of the triplet benzene were performed, based on which explained that, of the above G value of 1.4 for nitrogen formation, 0.8 can be attributed to the process via excited benzene in singlet state, and the remainder of the G value to the process via triplet state. Further experiments on γ-ray induced isomerization of stilbene in benzene containing AIBN have revealed that AIBN competes with trans-stilbene for the triplet benzene. The data obtained have been analyzed on the basis of competition kinetics, which has resulted in a value of 2.7 for the yield of the trip-let benzene.