sigma-delocalized radical cations (H(CH/sub 2/)/sub n/H)/sup +/ of primary alkanes: ESR evidence
Journal Article
·
· J. Phys. Chem.; (United States)
This paper describes the first clear evidence that n-alkane cations (H(CH/sub 2/)/sub n/H)/sup +/ with extended structures are characterized as delocalized sigma radicals. The unpaired electron in the in-plane sigma molecular orbital delocalizes over the entire chain, giving the characteristic 1:2:1 three-line ESR spectra due to the strong hyperfine couplings with the two in-plane end protons. The weak couplings with the out-of-plane CH/sub 2/ protons are unresolvable for most of the cations as is expected from the unpaired electron in the in-plane orbital. The major hyperfine couplings with the in-plane protons decrease with increasing carbon number from 152 G for C/sub 2/H/sub 6//sup +/ to 16 G for n-C/sub 10/H/sub 22//sup +/ depending upon the sigma delocalization over the extended chain. The coupling values obtained from the INDO calculations using standard geometry are in good agreement with the observation, although a slight tilt of the CH/sub 3/ axis was required for the lower alkane cations with n less than or equal to 4.
- Research Organization:
- Government Industrial Research Inst., Nagoya, Japan
- OSTI ID:
- 6127274
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:15; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALKANES
BARYONS
BUTANE
CATIONS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COUPLING
DECANE
DECOMPOSITION
DEUTERIUM
DEUTERIUM COMPOUNDS
ELECTRON SPIN RESONANCE
ELECTRONS
ELEMENTARY PARTICLES
ETHANE
FERMIONS
HADRONS
HEPTANE
HEXANE
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYPERFINE STRUCTURE
IONS
ISOTOPES
LEPTONS
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
NUCLEONS
OCTANE
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PENTANE
PROPANE
PROTONS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
RESONANCE
STABLE ISOTOPES
400600* -- Radiation Chemistry
ALKANES
BARYONS
BUTANE
CATIONS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COUPLING
DECANE
DECOMPOSITION
DEUTERIUM
DEUTERIUM COMPOUNDS
ELECTRON SPIN RESONANCE
ELECTRONS
ELEMENTARY PARTICLES
ETHANE
FERMIONS
HADRONS
HEPTANE
HEXANE
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYPERFINE STRUCTURE
IONS
ISOTOPES
LEPTONS
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
NUCLEONS
OCTANE
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PENTANE
PROPANE
PROTONS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
RESONANCE
STABLE ISOTOPES