Mass-Analyzed Ion Kinetic Energy Spectra of Chloroanisols: Application to the Interpretation of the Mass Spectra of Methoxybenzenesulfonyl Chlorides

1979 ◽  
Vol 12 (11-12) ◽  
pp. 823-832 ◽  
Author(s):  
Concetta Kascheres ◽  
Ruiess Van Fossen Bravo
Keyword(s):  
Kinetic Energy ◽  
Mass Spectra ◽  
Energy Spectra ◽  
Ion Kinetic Energy

The Ion Kinetic Energy Spectra of Benzyl Fluoride and the Isomeric Fluorotoluenes

1974 ◽  
Vol 52 (6) ◽  
pp. 867-869 ◽  
Author(s):  
S. Safe ◽  
W. D. Jamieson ◽  
D. J. Embree
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Energy ◽  
Mass Spectrometer ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Energy Spectra ◽  
Model Compounds ◽  
Free Region ◽  
Field Free Region ◽  
Ion Kinetic Energy

One of the classical problems in mass spectrometry is the structure and formation of the C7H7+ and XC7H6+ ions which are generated in the mass spectra of alkylbenzenes and many other aromatic compounds. The intermediacy of both symmetrical tropylium ion structures and unsymmetrical benzyl ions has been postulated using a number of different approaches. We have investigated this problem using ion kinetic energy spectroscopy, a relatively new technique, with the isomeric fluorobenzenes and benzyl fluoride as model compounds. Our results indicated incomplete substituent (i.e. fluorine) scrambling in the first field-free region of the mass spectrometer and thus incomplete equilibration in the decomposing FC7H6+ ions and these conclusions are in contrast to results obtained using other techniques.

Rearrangements in the Molecular Ions of Some ortho-Substituted Schiff Bases

1993 ◽  
Vol 46 (6) ◽  
pp. 895 ◽  
Author(s):  
T Blumenthal ◽  
M Dosen ◽  
RG Gillis ◽  
QN Porter
Keyword(s):  
Kinetic Energy ◽  
Schiff Bases ◽  
Molecular Ions ◽  
Energy Spectra ◽  
Supporting Evidence ◽  
Deuterium Labelling ◽  
Methyl Group ◽  
Molecular Ion ◽  
Fragment Ions ◽  
Ion Kinetic Energy

Under electron ionization conditions, the ortho-substituted Schiff bases N-benzylidene-o-toluidine (1a), N-(o-methylbenzylidene)aniline (1b), N-salicylideneaniline (1c) and N-(o-methoxybenzylidene)aniline (1d) give fragment ions which have been shown by collision-activated mass-analysed ion kinetic energy spectra to have the structure of the protonated molecular ions of indole (2), benzofuran (3), and 1,2-benzisoxazole (4). The molecular ion of N-(o-methylbenzylidene)-o-toluidine (1f) gives as fragment ions not only the protonated molecular ion (2) of indole and the tropylium ion but also the molecular ion of anthracene. Attempts to find supporting evidence for a mechanism for this rearrangement by deuterium labelling of a methyl group in (1b), such as (1g), have been unsuccessful.

Angle-dependence of ion kinetic energy spectra obtained by using mass spectrometers II. Experimental considerations and preliminary results on non-fragmenting systems

1984 ◽  
Vol 392 (1802) ◽  
pp. 89-106 ◽  
Keyword(s):  
Kinetic Energy ◽  
Energy Analysis ◽  
Energy Spectra ◽  
Observation Angle ◽  
Initial Angle ◽  
Mass Spectrometers ◽  
Small Uncertainty ◽  
Ion Kinetic Energy ◽  
Double Focusing ◽  
Selection Of

Experimental problems associated with studies of the scattering of kilovolt projectile ions in mass spectrometers designed primarily for chemical analysis are discussed. The parameters that are important in satisfactorily controlling and defining the actual scattering angle in relation to the observation angle are considered in detail. Two different experimental configurations are considered; angular selection before, or after kinetic energy analysis of the collision products. A modification to a VG ZAB-2F double-focusing mass spectrometer, in order to observe angle-resolved ion kinetic energy spectra of collisionally scattered ion beams, is described. Initial angle-resolved experiments on systems that do not involve fragmentation, have been performed. The results are presented for the angle-resolved energy loss spectra of Ar + and N 2 + and the angle-resolved charge-stripping of Ar + . A feature of the apparatus described is the small uncertainty in the angular selection of the analysing angle-resolved slit.

Sign in / Sign up

Export Citation Format

Share Document