Synthesis and mass spectra of piperidine and piperazine N-oxyl radicals

1987 ◽  
Vol 52 (9) ◽  
pp. 2266-2273 ◽  
Author(s):  
Viera Kaliská ◽  
Štefan Toma ◽  
Ján Leško
Keyword(s):  
Liquid Crystals ◽  
Electron Impact ◽  
Mass Spectra ◽  
Fragmentation Pattern ◽  
Spin Probes ◽  
Electron Impact Mass ◽  
Impact Mass

It has been found that ultrasound could accelerate the synthesis of piperidine and piperazine N-oxyl radicals. These radicals were investigated for their utilization as spin probes for checking the properties of liquid crystals. Electron impact mass spectra of the N-oxyl radicals were recorded and their fundamental fragmentation pattern was proposed.

Fragmentation of isomeric dideoxy derivatives of 1,6-anhydro-β-D-hexopyranoses under electron impact

1981 ◽  
Vol 46 (10) ◽  
pp. 2390-2403 ◽  
Author(s):  
František Tureček ◽  
Tomáš Trnka ◽  
Miloslav Černý
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Positional Isomers ◽  
Deuterium Labeling ◽  
Stereochemical Assignment ◽  
Electron Impact Mass ◽  
Derivatives Of ◽  
Impact Mass

Electron impact mass spectra of all possible dideoxy derivatives of 1,6-anhydro-β-D-hexopyranoses and their sixteen specifically deuterium-labeled derivatives are reported. The spectra of positional isomers differ considerably making possible the reliable location of the hydroxyl group by mass spectrometry. The configuration of the hydroxyl group at C(2) and C(4) has only a negligible effect on the fragmentation pattern of stereoisomers. However, mass spectra of the C(3)-configurational isomers differ sufficiently to permit a stereochemical assignment. The fragmentation paths were elucidated by means of deuterium labeling and metastable spectra.

Notizen: Fast Pulsed Laser Induced Electron Generation for Electron Impact Mass Spectrometry

1988 ◽  
Vol 43 (12) ◽  
pp. 1151-1153 ◽  
Author(s):  
E. R. Rohwer ◽  
R.C. Beavis ◽  
C. Köster ◽  
J. Lindner ◽  
J. Grotemeyer ◽  
...  
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Ion Source ◽  
Electron Impact Mass Spectrometry ◽  
Uv Laser ◽  
Electron Generation ◽  
Medium Resolution ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
Tof Ms

A new ultra fast electron impact (El) ion source is pre­sented that produces a very short, high intensity electron beam, allowing medium resolution mass spectra to be re­corded without pulsing the ion accelerating voltages in a time-of-flight mass spectrometer (TOF-MS). The ion source requires minimum modification of any TOF-MS equipped with an electrostatic ion reflector and UV-laser. El-spectra are presented for comparison with literature spectra.

ChemInform Abstract: MASS SPECTRA OF NITRONES. ELECTRON IMPACT MASS SPECTRA OF FLUORENONE NITRONES

1981 ◽  
Vol 12 (29) ◽  
Author(s):  
M. A. ABOU-GHARBIA ◽  
D. T. TERWILLIGER ◽  
M. M. JOULLIE ◽  
R. M. SRIVASTAVA
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Electron Impact Mass ◽  
Impact Mass

Electron impact mass spectra of δ-keto enol esters

1996 ◽  
Vol 2 (1) ◽  
pp. 129
Author(s):  
Teodor Balaban ◽  
Dietrich Müller
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Enol Esters ◽  
Electron Impact Mass ◽  
Impact Mass

Electron impact mass spectra of enamine esters, ketones and nitriles

1992 ◽  
Vol 27 (2) ◽  
pp. 123-125
Author(s):  
N. R. Ayyangar ◽  
R. J. Lahoti ◽  
Thomas Daniel ◽  
A. Sudalai
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Electron Impact Mass ◽  
Impact Mass
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