Trimethylsilyl transfer during electron ionization mass spectral fragmentation of someω-hydroxycarboxylic andω-dicarboxylic acid trimethylsilyl derivatives and the effect of chain length

Electron ionization (EI) mass spectral fragmentation routes of twelve 5-bromo-2,4-di-o-(m- and p-) chloro- (bromo-)benzyl-thiouracils and 6-methyluracils are investigated. The compounds studied are analyzed using gas chromatography/mass spectrometry (GC/MS). Fragmentation pathways, whose elucidation is assisted by accurate mass measurements and metastable transitions, are discussed. Correlation between the abundances of the selected fragment ions of the compounds investigated is discussed. The data obtained make grounds for distinction of structural isomers.

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Electron ionization mass spectral fragmentation study of sulfation derivatives of polychlorinated biphenyls

Chemistry Central Journal ◽

10.1186/1752-153x-3-5 ◽

2009 ◽

Vol 3 (1) ◽

Cited By ~ 10

Author(s):

Xueshu Li ◽

Larry W Robertson ◽

Hans-Joachim Lehmler

Keyword(s):

Polychlorinated Biphenyls ◽

Electron Ionization ◽

Ionization Mass ◽

Mass Spectral Fragmentation ◽

Mass Spectral ◽

Derivatives Of

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Electron ionization mass spectrometry of aryl- and fluoroalkyl-substituted palladium(II) β-diketonates and monothio-β-diketonates

Canadian Journal of Chemistry ◽

10.1139/v94-163 ◽

1994 ◽

Vol 72 (5) ◽

pp. 1302-1311 ◽

Cited By ~ 1

Author(s):

Mark L. J. Reimer ◽

John B. Westmore ◽

Manoranjan Das

Keyword(s):

Mass Spectra ◽

Electron Ionization ◽

Electron Ionization Mass Spectrometry ◽

Ionization Mass ◽

Aryl Group ◽

Mass Spectral ◽

Transition Series ◽

Electron Ionization Mass Spectra ◽

Positive Ion ◽

Sulfur Donor

Positive ion electron ionization mass spectra are presented for palladium(II) β-diketonates and monothio-β-diketonates of the general form PdII[RC(X)CHC(O)R′]2, where R = phenyl, 4-methoxyphenyl, 2-thienyl, or 2-naphthyl; R′ = trifluoromethyl, pentafluoroethyl, or n-heptafluoropropyl; and X = O or S. The mass spectral behavior is in sharp contrast to that of metals of the first transition series. The spectra of the β-diketonates are dominated by metal-containing ions that arise by migration of the R group from the ligand (L) to palladium, but there is no evidence for fluorine-to-metal transfer. These findings are consistent with HSAB theory. The strong tendency of palladium to form bonds with unsaturated carbon also leads to remarkably abundant metal-containing ions that arise by losses of CO or aryloxy radicals from [PdRL]+• ions. In contrast, in decompositions of ions in the spectra of the monothio-β-diketonates, migration of the R group is suppressed; competition for palladium dπ electrons by the sulfur donor makes palladium a poorer aryl group acceptor.

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Massenspektrometrische Fragmentierung von Trimethylsilylderivaten (TMS) des Thyrotropin-„Releasing“-Hormons (TRH) und dessen Teilstrukturen / Mass Spectroscopy of Trimethylsilyl Derivatives of Thyrotropin-releasing Hormone and its Constituents

Zeitschrift für Naturforschung B ◽

10.1515/znb-1973-11-1222 ◽

1973 ◽

Vol 28 (11-12) ◽

pp. 820-823 ◽

Cited By ~ 4

Author(s):

W. A. König ◽

S. Fuchs ◽

K. Zech ◽

W. Voelter

Keyword(s):

Mass Spectrometry ◽

Mass Spectroscopy ◽

Peptide Hormones ◽

Thyrotropin Releasing Hormone ◽

Mass Spectral Fragmentation ◽

Releasing Hormone ◽

Mass Spectral ◽

Trimethylsilyl Derivatives ◽

Fragmentation Patterns ◽

Derivatives Of

The mass spectral fragmentation patterns of trimethylsilyl derivatives of TRH and its constituents are discussed. The utility of these derivatives for the control of the synthesis of peptide hormones by mass spectrometry is obvious.

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