Free Radicals by Mass Spectrometry. VI. The Bond Dissociation Energies of Some Methyl, Allyl, and Benzyl Compounds by Electron Impact

1954 ◽  
Vol 22 (9) ◽  
pp. 1489-1492 ◽  
Author(s):  
F. P. Lossing ◽  
K. U. Ingold ◽  
I. H. S. Henderson
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Electron Impact ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies

FREE RADICALS BY MASS SPECTROMETRY: X. THE IONIZATION POTENTIALS OF METHYL SUBSTITUTED ALLYL RADICALS

1956 ◽  
Vol 34 (3) ◽  
pp. 345-353 ◽  
Author(s):  
C. A. McDowell ◽  
F. P. Lossing ◽  
I. H. S. Henderson ◽  
J. B. Farmer
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Electron Impact ◽  
Heat Of Formation ◽  
Ionization Potentials ◽  
Bond Dissociation Energies ◽  
Allyl Radical ◽  
Dissociation Energies ◽  
Allyl Halides ◽  
Vertical Ionization Potentials

The vertical ionization potentials of the β- and γ-methyl substituted allyl radicals as measured by electron impact are 8.03 ± 0.05 v. and 7.71 ± 0.05 v, respectively. From appearance potential data the following bond dissociation energies can be derived, assuming the dissociation processes to be free from complications:[Formula: see text]With assumptions about the structure of the ions produced by electron impact from the corresponding butenes the dissociation energies of the C4H7—H bonds in these latter compounds can be estimated, and the heats of formation of the corresponding radicals derived, namely:[Formula: see text]From data on the allyl halides we evaluate the heat of formation of the allyl radical to be:[Formula: see text]

FREE RADICALS BY MASS SPECTROMETRY: VII. THE IONIZATION POTENTIALS OF ETHYL, ISOPROPYL, AND PROPARGYL RADICALS AND THE APPEARANCE POTENTIALS OF THE RADICAL IONS IN SOME DERIVATIVES

1955 ◽  
Vol 33 (5) ◽  
pp. 861-869 ◽  
Author(s):  
J. B. Farmer ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrometry ◽  
Thermal Decomposition ◽  
Free Radicals ◽  
Kinetic Energy ◽  
Electron Impact ◽  
Ionization Potentials ◽  
Bond Dissociation Energies ◽  
Radical Ions ◽  
Dissociation Energies ◽  
Propargyl Radicals

The ionization potentials of ethyl, isopropyl, and propargyl radicals have been measured by electron impact on radicals produced by thermal decomposition of appropriate compounds. The values are:ethyl 8.78±0.05 ev., isopropyl 7.90±0.05 ev., and propargyl 8.25±0.08 ev. From the appearance potentials of these ions in various compounds, the following values of bond dissociation energies were obtained:[Formula: see text][Formula: see text] assuming no kinetic energy of the products.

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