Replacement reactions of EC-produced 211At in benzene and halobenzenes
- 1. Joint Inst. for Nuclear Research, Dubna (USSR)
- 2. Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Nuklearchemie
- 3. Kozponti Fizikai Kutato Intezet, Budapest (Hungary)
Description
Halogen and hydrogen replacement reactions in gaseous, liquid and solid benzene and halobenzenes by astatine atoms produced via the 211Rn(EC)211At nuclear process were investigated. The halogen replacement increases in the order C6H5F < C6H5Cl < C6H5Br < C6H5I, while the hydrogen replacement decreases in the same order. The halogen substitution yields were found to be linearly dependent on the bond strength of the halogen to be replaced in both liquid and gaseous systems. The isomer distribution of hydrogen replacement products is nearly statistical in all the halobenzenes, independent of the phase. In liquid and solid aniline the hydrogens substitution yields were found to be in the same range. The results lead to the conclusion that the replacement reactions of EC-produced 211At in the systems studied are hot homolytic processes, similar to those of hot halogens formed via (n,γ) and (n,2n) nuclear reactions. (orig.)
Abstract (German)
Untersuchung von Halogen- und Wasserstoff-Ersatzreaktionen in gasfoermigen, fluessigen und festen Halobenzolen und in Benzol durch Astatinatome aus dem Kernprozess 211Rn(EC) 211At. Der Halogenersatz steigert sich in der Reihenfolge C6H5F < C6H5Cl < C6H5Br < C6H5I, waehrend der Ersatz des Wasserstoffs in derselben Reihenfolge abfaellt. Es zeigte sich, dass die Halogen-Substitutionsausbeuten linear abhaengig sind von der Bindungsstaerke des Halogens, das ersetzt werden soll in fluessigen und gasfoermigen Systemen. Die Isomerenverteilung der Wasserstoff-Ersatzprodukte ist in allen Halobenzolen annaehernd statistisch, unabhaengig von der Phase. In fluessigem und festem Anilin lagen die Wasserstoff-Substitutionsausbeuten in demselben Bereich. Aus den Ergebnissen ist zu schliessen, dass die Ersatzreaktionen von EC-produziertem 211At in den untersuchten Systemen heisse, homolytische Prozesse sind, aehnlich denen von heissen Halogenen, die ueber die Kernreaktionen (n,γ) und (n,2n) gebildet werden. (orig.)Additional details
Publishing Information
- Journal Title
- Radiochim. Acta
- Journal Volume
- 26
- Journal Issue
- 3/4
- Series
- Radiochim. Acta.
- Journal Page Range
- 171-176
- ISSN
- 0033-8230
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 11543387
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Descriptors DEI
- ASTATINE 211; BENZENE; CHEMICAL REACTION YIELD; ELECTRON CAPTURE DECAY; GASES; HOT ATOM CHEMISTRY; ISOTOPE PRODUCTION; LIQUIDS; LOSSES; ORGANIC HALOGEN COMPOUNDS; SCAVENGING; SOLIDS
- Descriptors DEC
- ALPHA DECAY RADIOISOTOPES; AROMATICS; ASTATINE ISOTOPES; BETA DECAY; BETA DECAY RADIOISOTOPES; CHEMISTRY; DECAY; ELECTRON CAPTURE RADIOISOTOPES; FLUIDS; HEAVY NUCLEI; HOURS LIVING RADIOISOTOPES; HYDROCARBONS; ISOTOPES; NUCLEAR DECAY; NUCLEI; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; RADIOCHEMISTRY; RADIOISOTOPES
Optional Information
- Notes
- Presented in part at the 9th International Hot Atom Chemistry Symposium, Blacksburg, Va., USA, Sep 19 - 23, 1977.