Phase and (H/D)-lsotope Effects in the Radiochemical Yields of ¹³N-Compounds Formed in Pile- Irradiated Benzene and Cyclohexane

Abstract

The radiochemical yields of 13 Ν in various chemical forms such as DC 13 N, 13 ND,, C 6 D 5 C 13 N, C 6 D s 13 ND 2 , C 6 D,, C 13 Ν and C 6 D,, 13 ND 2 , formed in benzene-d 6 and cyclohexane-d 12 irradiated in a nuclear reactor through the 1J C(d, n) 13 Ν reaction, were estimated and compared with the results in protiated benzene and cyclohexane. Typical phase effect was observed in most of the product 13 N-compounds accompanied by the phase change of the irradiated media from solid to liquid, but the degree of the phase effect was smaller than that in the protiated media. With the phase change of benzene-d 6 , the decrease of C 6 D S C 13 N (ca. 17%) was equal to the sum of the increase of DC 13 N, CD 3 C 13 Ν and C 2 D S C 13 N, and the decrease of C 6 D 5 13 ND 2 was nearly equal to the increase of 13 ND 3 (ca. 3.5%). The results in cyclohexane-d 12 were just like in the case of benzene-d 6 . These data were explained by the diffusion-controlled reaction mechanism involving hydrogen atoms as a precursor. The reaction range and probability of the abstraction reaction between a hot nitrogen atom and the media molecules producing CN or ND radical was also discussed.