The remarkable electron impact mass spectrum of (2-benzyl-1,3-xylylene)-15-crown-4: expulsion of triethylene glycol by double hydrogen transfer

1996 ◽  
pp. 925 ◽  
Author(s):  
Gert-Jan M. Gruter ◽  
Ben L. M. van Baar ◽  
Tom J. Gerrits ◽  
Otto S. Akkerman ◽  
Friedrich Bickelhaupt ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Hydrogen Transfer ◽  
Triethylene Glycol ◽  
Electron Impact Mass Spectrum ◽  
Electron Impact Mass ◽  
Double Hydrogen ◽  
Impact Mass

Spectrométrie de masse du chloro-1 diméthoxy-2,6 naphtalène; comparaison de données théoriques et expérimentales

1983 ◽  
Vol 61 (9) ◽  
pp. 2089-2091 ◽  
Author(s):  
Jean-Claude Richer ◽  
Simone Odiot
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Electron Impact Mass Spectrum ◽  
Relative Stabilities ◽  
Spectrométrie De Masse ◽  
Electron Impact Mass ◽  
Impact Mass

In an unambiguous manner we have synthesized 1-chloro-2,6-dimethoxy-d3-naphthalene (5) and examined its electron impact mass spectrum. We report here calculations on the relative stabilities of 1-chloro and 5-chloro-6-methoxy-2-naphthols (4a and 4b) and on the relative stabilities of the O—CH3 bond in the 2 and 6 positions of compound 5. [Journal translation]

The Fragment Ion C13H9O2 m/z 197 in the Mass Spectra of 2-(2′-R-phenyl)benzoic Acids

1990 ◽  
Vol 43 (1) ◽  
pp. 203 ◽  
Author(s):  
RG Gillis ◽  
QN Porter
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Electron Impact Mass Spectrum ◽  
Benzoic Acids ◽  
Ipso Substitution ◽  
Methane Chemical Ionization ◽  
Electron Impact Mass ◽  
Impact Mass

In the electron impact mass spectrum of 2-(2°-R-phenyl)benzoic acids where R=H, NO2, OCH3, COOH, or Br, an abundant fragment ion m/z 197 is formed by an ipso substitution in which R is expelled as a radical. The structure of the ion m/z 197 has been shown by collision-activated dissociation to be identical with that of the protonated molecule formed by methane chemical ionization of 6H-dibenzo[ b,d ]pyran-6-one.

Oxygen equilibration in the mass spectra of 2-benzoylbenzoic acid

1976 ◽  
Vol 29 (2) ◽  
pp. 301
Author(s):  
MJ Lacey ◽  
JS Shannon
Keyword(s):  
Mass Spectrum ◽  
Benzoic Acid ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Molecular Ions ◽  
Electron Impact Mass Spectrum ◽  
Primary Fragmentation ◽  
Electron Impact Mass ◽  
Impact Mass

Positional integrity of the label is maintained in the molecular ions of 2-ben~oyl[18O]benzoic acid prior to a number of primary fragmentation modes. Positional integrity is also evident for some source and metastable reactions of the protonated molecular ions formed in its chemical ionization (H2) mass spectrum. The (M-Ph)+ ions formed in the electron impact mass spectrum, however, fragment further after complete equilibration of their oxygen atoms.

Electron Impact Mass Spectroscopy for Identification of Phencyclidine

1986 ◽  
Vol 69 (5) ◽  
pp. 814-820
Author(s):  
Charles C Clark
Keyword(s):  
Mass Spectrum ◽  
High Resolution ◽  
Electron Impact ◽  
Mass Spectroscopy ◽  
Phenyl Ring ◽  
Labeled Compounds ◽  
Electron Impact Mass ◽  
High Resolution Mass Spectroscopy ◽  
Impact Mass ◽  
Resolution Mass

Abstract The electron impact mass spectrum of phencyclidine (PCP) was studied using both deuterium-labeled analogs and high-resolution mass spectroscopy. The deuterium-labeled compounds used were d5.PCP having 5 deuterium atoms on the phenyl ring, d10.PCP having 10 deuterium atoms on the cyclohexyl ring, and d15.PCP having deuterium atoms on both the phenyl and cyclohexyl rings. The identities of some major fragments and some possible pathways for their formation are shown. Electron impact mass spectroscopy is shown to be a definitive test for the identification of PCP.

Mass Spectrometric Studies of the Ionization and Thermal Decomposition of Tungsten π-Cyclopentadienyl Tricarbonyl Dimer

1975 ◽  
Vol 53 (5) ◽  
pp. 628-632 ◽  
Author(s):  
J. R. Krause ◽  
D. R. Bidinosti
Keyword(s):  
Thermal Decomposition ◽  
High Temperature ◽  
Mass Spectrum ◽  
Temperature Dependence ◽  
Electron Impact ◽  
Enthalpy Change ◽  
Mass Spectrometric ◽  
Molecular Flow ◽  
Electron Impact Mass ◽  
Impact Mass

The ionization and thermal decomposition of tungsten π-cyclopentadienyl tricarbonyl dimer [WC5H5(CO)3]2 was investigated using a mass spectrometer fitted with single and double cell molecular flow inlet systems.The electron impact mass spectrum and appearance potentials for the principle ions in the spectrum have been measured and recorded.The enthalpy change for the dissociation[Formula: see text]obtained from van't Hoff plots of the temperature dependence of the equilibrium constant was found to be 234.4 ± 3.8 kJ/mol. This result was substantiated by an electron impact value of 221.0 ± 20.1 kJ/mol based on an ionization potential for ·WC5H5(CO)3 of 7.66 ± 0.05 eV measured in the high temperature studies.

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