Quasi-Equilibrium Theory of Mass Spectra

1963 ◽  
pp. 1-64 ◽  
Author(s):  
H.M. Rosenstock ◽  
M. Krauss
Keyword(s):  
Mass Spectra ◽  
Equilibrium Theory ◽  
Quasi Equilibrium

Improved Rate Expression in the Quasi‐Equilibrium Theory of Mass Spectra

1962 ◽  
Vol 37 (6) ◽  
pp. 1276-1283 ◽  
Author(s):  
Marvin Vestal ◽  
Austin L. Wahrhaftig ◽  
William H. Johnston
Keyword(s):  
Mass Spectra ◽  
Equilibrium Theory ◽  
Quasi Equilibrium ◽  
Rate Expression

The isolation of 11-oxotetrahydrorhombifoline from Ormosia coutinhoi and a study of its mass spectrum

1967 ◽  
Vol 45 (7) ◽  
pp. 751-757 ◽  
Author(s):  
Stewart McLean ◽  
A. G. Harrison ◽  
D. G. Murray
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Mass Spectra ◽  
Equilibrium Theory ◽  
Side Chain ◽  
Fragmentation Reaction ◽  
Quasi Equilibrium ◽  
Molecular Ion ◽  
Dihydro Derivative ◽  
A Minor

11-Oxotetrahydrorhombifoline (I) has been isolated from the alkaloidal extract of the bark of Ormosia coutinhoi, and its dihydro derivative II has been prepared. An examination of the mass spectra of these compounds and of their 3,3-d2 derivatives has led to the elucidation of the course of the major electron impact induced fragmentations undergone by the molecules. The main fragmentation of I leads to loss of C3H5 from the side chain to form an ion of m/e 221, with a minor path involving a central fission of the molecular ion to form an ion of m/e 150. The mass spectrum of II shows that the loss of C3H7 to form the ion of m/e 221 is a minor process, the main fragmentation reaction involving a central fission to form an ion of m/e 152 analogous to the ion of m/e 150 from I. This change in the spectrum is shown to be consistent with predictions based on the quasi-equilibrium theory of mass spectra.

ortho-Effects in Mass Spectra. Alteration of the Molecular-Ion Energy Distribution in Disubstituted Acetanilides

1972 ◽  
Vol 27 (4) ◽  
pp. 670-677 ◽  
Author(s):  
Steven Benezra ◽  
Maurice Bursey
Keyword(s):  
Excited State ◽  
Mass Spectra ◽  
Transition Probability ◽  
Substituent Effects ◽  
Quasi Equilibrium ◽  
Ion Energy ◽  
Ion Energy Distribution ◽  
Molecular Ion ◽  
Equilibrium Calculations ◽  
Excitation Probability

Abstract Simplified quasi-equilibrium calculations performed on the mass spectra of dihalosubstituted phenyl acetates and acetanilides again uncover the same substituent effects on the rise of K with E for the loss of ketene from phenyl acetates as was determined for the monosubstituted phenyl acetates. However, a new effect is found for the disubstituted acetanilides, removal of excitation probability for low-lying energy states of the molecular ion. This effect parallels the removal of transition probability for the lowest excited state of the neutral molecule.

Substituent effects in unimolecular ion decompositions. XV. Mechanistic interpretations and the quasi-equilibrium theory

1970 ◽  
Vol 92 (23) ◽  
pp. 6867-6880 ◽  
Author(s):  
Fred W. McLafferty ◽  
Timothy. Wachs ◽  
Chava. Lifshitz ◽  
Giuseppe. Innorta ◽  
Philip. Irving
Keyword(s):  
Substituent Effects ◽  
Equilibrium Theory ◽  
Quasi Equilibrium
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