- Radical Yields in the Radiolysis of Branched Hydrocarbons: Tertiary C-H Bond Rupture in 2,3-Dimethylbutane, 2,4-Dimethylpentane, and 3-Ethylpentane
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Gel permeation chromatography has been applied to iodine scavenging studies of the distribution of radicals produced in the radiolysis of symmetrically branched hydrocarbons 2,3-dimethylbutane, 2,4-dimethylpentane, and 3-ethylpentane. The principal iodides observed are those expected as a result of simple bond rupture. In the case of 2,3-dimethylbutane all five expected iodides are readily resolvable and it is shown that the loss of H from a tertiary position is favored over loss from a primary position by a factor of ~10. A similar ratio is also observed for 2,4-dimethylpentane. The higher ratio of 15 observed for 3-ethylpentane indicates a dependence on the number of tertiary sites on the alkane. The relative yield of ~3.3 for the loss of secondary and primary H atoms from 2,4-dimethylpentane and 3-ethylpentane is similar to that for normal alkanes, indicating a negligible effect of the adjacent tertiary carbon. In all three cases the rupture of terminal C-C bonds is relatively infrequent with C-C rupture occurring preferentially at the bonds adjacent to the tertiary carbon.
- Schuler, Robert H.,Wojnarovits, Laszlo
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p. 9240 - 9247
(2007/10/03)
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- PHOTOLYSE DE HI DANS UNE MATRICE HYDROCARBONEE VITREUSE A 77 K
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Stable products from the photolysis of HI in methyl-3 pentane (3 MP) or dimethyl-2,3 butane (23 DMB) quenched solid at 77 K are analyzed by capillary gas chromatography.Selective formation of a tertiary radical is proposed for the 23 DMB/HI system ; in 3 MP/HI, C-H bond rupture is also localized at the weakest tertiary bond, however the scission is not selective.
- Laet, M. de,Tilquin, B.
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