Effect of Dilution on Substitution Reactions of EC-Produced ²¹¹At with Chiorobenzene

No-Carrier-Added Radiohalogenation Methods with Heavy Halogens

“…Generally, a high specific activity is desirable, which can only be achieved by non-isotopic exchange. Although a large fraction of radiohalogenated aromatic compounds have been labeled by halogen exchange reactions, only a few attempts were made to use brominated compounds as precursors for aromatic radioiodination [69,[84][85][86][87][88][89] or radiobromination [90]. When comparing isotopie and non-isotopic exchange radioiodination of 4-iodoantipyrine, almost quantitative yields were obtained by iodine replacement, compared to 80% by bromine substitution in acidic aqueous solutions [84,85].…”

“…When comparing isotopie and non-isotopic exchange radioiodination of 4-iodoantipyrine, almost quantitative yields were obtained by iodine replacement, compared to 80% by bromine substitution in acidic aqueous solutions [84,85]. A high yield was also obtained in the iodine-for-bromine substitution in 4-bromometyrapone in a melt of the substrate [86], in bromobenzene in various solvents at 210°C [87,88], and in bromoantipyrine on silica gel [89].…”

Replacement Reactions of Recoil Halogens with Benzene Derivatives

“…Somewhat unexpectedly this has been found to be true not only for halogens forming in (n, 2n) and (η, γ) nuclear processes with high initial kinetic energy [25,26] but also for those originating via EC with relatively low kinetic and high ionization and excitation energy [27,36,37], This indicates fast neutralization of originally ionized recoil species [36,37,39] followed by their reactions as neutral atoms that still possess definite excess energy.…”

Some Replacement and Addition Reactions of Astatine

“…In the middle of seventies more systematic investigations started in the Laboratory of Nuclear Problems of the JINR on the replacement reactions of EC-produced astatine with simple aromatic compounds [29,31,37,43]. Special attention was paid to the main factors controlling these reactions, as well as to the isomer distribution of the hydrogen substitution in gas and liquid phase aromatic compounds.…”