Radical products of γ-radiolysis of 12-crown-4 at 77 K
- 1. RAN, Inst. Sinteticheskikh Polimernykh Materialov im. N.S. Enikolopova, Moscow (Russian Federation)
- 2. Moskovskij Gosudarstvennyj Univ. im. M.V. Lomonosova, Moscow (Russian Federation)
Description
Paramagnetic products of γ-radiolysis of 12-crown-4 and its solutions in CFCl3 and CFCl2CF2Cl at 77 K were studied by ESR spectroscopy. It was found that the ESR spectra of 12-crown-4 irradiated with γ-rays at 77 K contained superimposing signals of at least two species, the radicals resulting from macrocycle opening -C radical H-C(H) = O and macrocyclic radicals -O-C radical H-CH2-, which are formed with nearly equal yields. It was shown that -O-C radical H-CH2- radicals rapidly decayed at temperatures above 140 K. However, the -C radical H-C(H)=O radicals are stable almost up to the matrix softening temperature. The radical cations of 12-crown-4 are not stabilized in the matrices of Freon 11 and Freon 113, since they undergo transformation to macrocyclic radicals O-C radical H-CH2- via the deprotonation reaction
Abstract (Russian)
Методом ЭПР-спектроскопии изучены парамагнитные продукты γ-радиолиза 12-краун-4 и его растворов в CFCl3 и CFCl2CF2Cl при 77 К. Обнаружено, что спектры ЭПР γ-облученного при 77 К 12-краун-4 представляют собой суперпозицию сигналов, по меньшей мере, двух радикалов: радикалов разрыва макроцикла -С radicalН-С(Н) = О и макроциклических радикалов -О-С radicalН-СН2-, которые образуются примерно с равными выходами. Показано, что быстрая гибель -О-С radicalН-СН2- происходит при температуре >140 К, в то время как радикалы -С radicalН-С(Н)=О устойчивы практически до температуры размораживания образца. В матрицах фреона-11 и фреона-113 катион-радикалы краун-эфира не стабилизируются, а превращаются в макроциклические радикалы -О-С radicalН-СН2- в результате реакции депротонированияAdditional details
Additional titles
- Original title (Russian)
- Радикальные продукты γ-радиолиза 12-краун-4 при 77 К
Publishing Information
- Journal Title
- Khimiya Vysokikh Ehnergij
- Journal Volume
- 41
- Journal Issue
- 2
- Journal Page Range
- p. 95-101
- ISSN
- 0023-1193
- CODEN
- KHVKAO
INIS
- Country of Publication
- Russian Federation
- Country of Input or Organization
- Russian Federation
- INIS RN
- 38067638
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Descriptors DEI
- CHEMICAL REACTION KINETICS; CROWN ETHERS; ELECTRON SPIN RESONANCE; FREONS; G VALUE; GAMMA RADIATION; RADIATION DOSES; RADICALS; RADIOLYSIS; REACTION INTERMEDIATES; SOLUTIONS; SPECTRA; STABILITY; TEMPERATURE RANGE 0065-0273 K
- Descriptors DEC
- CHEMICAL RADIATION EFFECTS; CHEMICAL REACTIONS; DECOMPOSITION; DISPERSIONS; DOSES; ELECTROMAGNETIC RADIATION; ETHERS; HALOGENATED ALIPHATIC HYDROCARBONS; HOMOGENEOUS MIXTURES; IONIZING RADIATIONS; KINETICS; MAGNETIC RESONANCE; MIXTURES; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; ORGANIC OXYGEN COMPOUNDS; RADIATION EFFECTS; RADIATIONS; REACTION KINETICS; RESONANCE; TEMPERATURE RANGE
Optional Information
- Notes
- 24 refs., 4 figs.