The Ionization Potentials of Substituted Acetylenes by Electron Impact

1954 ◽  
Vol 76 (7) ◽  
pp. 1994-1997 ◽  
Author(s):  
J. L. Franklin ◽  
F. H. Field
Keyword(s):  
Electron Impact ◽  
Ionization Potentials ◽  
Substituted Acetylenes

Radikalionen, 61 [1, 2]Dialkylamino-substituierte Acetylene und Allene:Ionisation, Oxidation und AlCl3-katalysierte Wasserstoffübertragung / Radical Ions, 61 [1, 2]Dialkylamino-substituted Acetylenes and Allenes:Ionisation, Oxidation and AlCl3-Catalyzed Hydrogen Transfer

1984 ◽  
Vol 39 (6) ◽  
pp. 763-770 ◽  
Author(s):  
Hans Bock ◽  
Wolfgang Kaim ◽  
Mitsuo Kira ◽  
Louis Réné ◽  
Heinz-Günther Viehe
Keyword(s):  
Radical Cation ◽  
Hydrogen Transfer ◽  
Radical Cations ◽  
Esr Spectra ◽  
Ionization Potentials ◽  
Radical Ions ◽  
Substituted Acetylenes

AbstractThe photoelectron (PE) spectra of bis(dialkylamino) acetylenes R2N-C≡C-NR2 and of tetrakis(dialkylamino) allenes (R2N)2C=C=C(NR2)2 with R = CH3, C2H5 exhibit characteristic ionization patterns which are assigned to π radical cation states of the two molecular halves twisted against each other. The low first ionization potentials between 7.0 eV and 7.7 eV stimu­lated attempts to oxidize using AlCl3 in H2CCl2 or D2CCl2. The hyperfine structured ESR spectra observed can be unequivocally assigned to the ethylene radical cations R2N-HC=CH -NR2˙⊕ which are formed from the obviously non-persistent species R2N-C≡C-NR2˙⊕ via a hydrogen transfer. During the oxidation of the dialkylamino-substituted allenes no paramagnetic intermedi­ates could be detected, presumably due to a rapid dimerisation of the allene radical cation (R2N)2C=C=C(NR2)2˙⊕.

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.

THE IONIZATION POTENTIALS OF MONOSUBSTITUTED PYRIDINES BY ELECTRON IMPACT

1963 ◽  
Vol 67 (7) ◽  
pp. 1551-1554 ◽  
Author(s):  
Michael R. Basila ◽  
Donald J. Clancy
Keyword(s):  
Electron Impact ◽  
Ionization Potentials

IONIZATION POTENTIALS OF METHYL-SUBSTITUTED BENZENES AND CYCLOPENTADIENES

1964 ◽  
Vol 42 (10) ◽  
pp. 2256-2261 ◽  
Author(s):  
F. Meyer ◽  
A. G. Harrison
Keyword(s):  
Electron Impact ◽  
Experimental Results ◽  
Ionization Potentials ◽  
Orbital Method ◽  
Substituted Benzenes ◽  
Group Orbital

The ionization potentials of a number of methyl-substituted benzenes and cyclopentadienes have been measured by electron impact. The experimental results are compared to calculations based on a group orbital method.

Cyclic phosphines and arsines. II. Cyclic arsines

1970 ◽  
Vol 23 (8) ◽  
pp. 1559 ◽  
Author(s):  
PS Elmes ◽  
S Middleton ◽  
BO West
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Electron Impact ◽  
Systematic Study ◽  
Variable Temperature ◽  
Mass Spectrometric ◽  
Ionization Potentials ◽  
Methyl Ethyl ◽  
Mass Spectrometric Techniques ◽  
Nuclear Magnetic

The constitutions of the cyclopolyarsines (AsR)n (R = methyl, ethyl, n-propyl, and phenyl) have been investigated by nuclear magnetic resonance and mass spectrometric techniques. A systematic study of their fragmentation under electron impact at different ionization potentials has confirmed the presence of pentameric alkyl and hexameric phenyl cyclic arsines. Variable temperature N.M.R. spectra obtained for pentamethylcyclopentaarsine have been interpreted in terms of a rapid pseudorotation process. Some mixed methylphenyl cyclic arsines have been identified.

Sign in / Sign up

Export Citation Format

Share Document