NUCLEAR RECOIL REACTIONS IN CYCLOPENTADIENYLMANGANESE TRICARBONYL

Abstract

The first stages in an intensive study of Szilard–Chalmers recoil reactions in a covalent metal-organic compound are described. The radioactive manganese-56 is found, as expected, as inorganic manganese (75–80%), as the parent compound (12–20%), and as one or other of two hitherto unidentified, unstable compounds depending on whether anhydrous paper chromatography or paper ionography is used as the separation method (5–7%). Some data are given showing the effect of room-temperature annealing following irradiation at −196 °C. In particular, the yield of one of the unidentified compounds increases markedly (to ~15%) while that of the other compound remains nearly unaffected.Thin-layer chromatography in anhydrous benzene was used as separation method in thermal annealing studies. They show two hitherto unreported phenomena: The apparent retention increases considerably and then decreases again as annealing continues, and the annealing reaction at two temperatures in the liquid and one in the solid phase are qualitatively very similar. These results are interpreted as indicating the presence of another species, the "pseudoparent", which is not distinguished chromatographically from the parent. Some discussion is given as to possible mechanisms.