ESR spectra and structures of radical cations of some branched alkanes:. beta. -proton couplings in C--C sigma cations
The systematic ESR studies of radical cations of five kinds of methyl substituted butanes show that the unpaired electron is rather confined to one of the C--C sigma bonds in contrast to the linear alkane cations, in which the unpaired electron delocalizes over the entire sigma molecular chain. Analyses of the origin of the trans C--H/sub ..beta../ proton couplings indicate that spin transfer due to hyperconjugation plays an important role in these branched alkane cations. It is also shown that the hyperconjugative effect in these branched alkane cations is two times higher than that in the neutral alkyl ..pi.. radicals. The large difference of the front and back lobe interactions in the ..beta..-proton couplings in these C--C sigma radicals is attributable to the bent structure of the radical carbon atom. The front lobe interaction is about one-half of that of the back lobe interaction as is the case of vinyl radicals.
- Research Organization:
- Government Industrial Research Institute, Nagoya, Hirate, Kita, Nagoya 462, Japan
- OSTI ID:
- 5727896
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 79:6
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALKANES
ELECTRON SPIN RESONANCE
MOLECULAR STRUCTURE
HALOGENATED ALIPHATIC HYDROCARBONS
RADIOLYSIS
ALKYL RADICALS
CATIONS
VINYL RADICALS
X RADIATION
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ELECTROMAGNETIC RADIATION
HYDROCARBONS
IONIZING RADIATIONS
IONS
MAGNETIC RESONANCE
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RESONANCE
400600* - Radiation Chemistry