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The Resonance Energy of Cycloheptatrienyl Radical.

AD694138

Publication Date	1968
Personal Author	Vincow, G.; Dauben, H. J.; Hunter, F. R.; Volland, W. V.
Page Count	9
Abstract	The homolytic thermal cleavage of neat liquid bitropenyl (bi-2,4,6-cycloheptatrien-1-yl) to form the cycloheptatrienyl (tropenyl) radical, C7H7., has been investigated by means of electron spin resonance spectroscopy. The enthalpy of this dissociation reaction has been evaluated from the variation of the intensity of the hyperfine components of C7H7. as a function of temperature. Using this value the 'extra' resonance energy (RE) of C7H7. is estimated to be 21 kcal/mole and the total empirical RE to be 31 kcal/mole. Comparison of this result with previous work reveals that tropenyl radical is among the most extensively resonance-stabilized free radicals. From the measured value of the enthalpy of dissociation other thermochemical quantities are estimated. Empirical resonance energies are correlated with calculated delocalization energies. (Author)
Keywords	Cycloalkenes Free radicals Electron spin resonance Heat of reaction Dissociation Heat of formation Reprints Cycloheptatriene compounds Bicycloheptatrienyl
NTIS Subject Category	99F - Physical & Theoretical Chemistry
Corporate Authors	Washington Univ Seattle Dept Of Chemistry
Document Type	Journal Article
NTIS Issue Number	196922

The Resonance Energy of Cycloheptatrienyl Radical.

The Resonance Energy of Cycloheptatrienyl Radical.
AD694138

Publication Date	1968
Personal Author	Vincow, G.; Dauben, H. J.; Hunter, F. R.; Volland, W. V.
Page Count	9
Abstract	The homolytic thermal cleavage of neat liquid bitropenyl (bi-2,4,6-cycloheptatrien-1-yl) to form the cycloheptatrienyl (tropenyl) radical, C7H7., has been investigated by means of electron spin resonance spectroscopy. The enthalpy of this dissociation reaction has been evaluated from the variation of the intensity of the hyperfine components of C7H7. as a function of temperature. Using this value the 'extra' resonance energy (RE) of C7H7. is estimated to be 21 kcal/mole and the total empirical RE to be 31 kcal/mole. Comparison of this result with previous work reveals that tropenyl radical is among the most extensively resonance-stabilized free radicals. From the measured value of the enthalpy of dissociation other thermochemical quantities are estimated. Empirical resonance energies are correlated with calculated delocalization energies. (Author)
Keywords	Cycloalkenes Free radicals Electron spin resonance Heat of reaction Dissociation Heat of formation Reprints Cycloheptatriene compounds Bicycloheptatrienyl
NTIS Subject Category	99F - Physical & Theoretical Chemistry
Corporate Authors	Washington Univ Seattle Dept Of Chemistry
Document Type	Journal Article
NTIS Issue Number	196922