Soft Cold EI - approaching molecular ion only with electron ionization

2015 ◽  
Vol 29 (21) ◽  
pp. 1954-1960 ◽  
Author(s):  
Aviv Amirav ◽  
Uri Keshet ◽  
Albert Danon
Keyword(s):  
Electron Ionization ◽  
Molecular Ion ◽  
Cold Ei

Intensity of molecular ion peak in electron ionization mass spectra

2012 ◽  
Vol 67 (14) ◽  
pp. 1066-1068 ◽  
Author(s):  
A. S. Samokhin ◽  
I. A. Revelsky
Keyword(s):  
Mass Spectra ◽  
Electron Ionization ◽  
Ionization Mass ◽  
Molecular Ion ◽  
Electron Ionization Mass Spectra

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

1993 ◽  
Vol 71 (9) ◽  
pp. 1450-1462 ◽  
Author(s):  
Mark L.J. Reimer ◽  
John B. Westmore ◽  
Manoranjan Das
Keyword(s):  
Mass Spectra ◽  
Hydrogen Transfer ◽  
Electron Ionization ◽  
Central Position ◽  
Ionization Mass ◽  
Aryl Group ◽  
Molecular Ion ◽  
Transfer Processes ◽  
Mechanisms Of Formation ◽  
Positive Ion

Electron ionization positive-ion mass spectra are reported for 18 substituted nickel(II) β-diketonates and monothio-β-diketonates, NiII(RCXCHCOR′)2, where X = O or S; R = phenyl, 2-thienyl, 5-methyl-2-thienyl, or 2-naphthyl; and R′ = difluoromethyl, trifluoromethyl, pentafluoroethyl, or n-heptafluoropropyl. Each mass spectrum contains a prominent molecular ion, [NiL2]+, which, for β-diketonates, fragments mainly by elimination of the odd-electron R′• species; the resulting ion decomposes by losses of one or more even-electron neutral species to yield ions containing nickel(II). In contrast, the major fragmentation of the molecular ion of monothio-β-diketonates is loss of NiIL to yield an abundant L+ ion. Furthermore, while most ions contain nickel(II), some prominent ions contain nickel(I); among these are [NiISC(R) = CH]+ and [NiI(HCCR)]+. Interesting ions are formed by hydrogen transfer processes. The [NiHL]+ ion is favored in the spectra of β-diketonates having a phenyl substituent, consistent with hydrogen transfer to the metal from the aryl group. On the other hand, the [Ni(L–H)]+ ion, favored for the monothio-β-diketonates, could be formed by hydrogen transfer from the central position of the chelate ring or from an aryl substituent. Alternative mechanisms of formation are discussed. Some minor ions are formed by fluorine transfer to nickel. The trends in their abundances are influenced by the hardness of nickel as an acid in its different oxidation states, under the influence of the ligand donor atoms, and by the hardness of the carbon atoms of the perfluoroalkyl substituents.

Reduction Reactions in the Ion Source in Electron Ionization Mass Spectrometry

2020 ◽  
Vol 75 (13) ◽  
pp. 1685-1692
Author(s):  
D. M. Mazur ◽  
M. E. Zimens ◽  
Th. B. Latkin ◽  
N. V. Ul’yanovskii ◽  
V. B. Artaev ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Source ◽  
Electron Ionization ◽  
Electron Ionization Mass Spectrometry ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Reduction Reactions

Simulation of the electron ionization mass spectra of the Novichok nerve agent

2021 ◽  
Author(s):  
Francisco C. S. Chernicharo ◽  
Lucas Modesto‐Costa ◽  
Itamar Borges
Keyword(s):  
Mass Spectra ◽  
Nerve Agent ◽  
Electron Ionization ◽  
Ionization Mass ◽  
Electron Ionization Mass Spectra

A novel rearrangement in the gas phase under electron ionization for 3-glycosyl-5-aryl-2-isoxazolines

1999 ◽  
Vol 34 (9) ◽  
pp. 915-921 ◽  
Author(s):  
Norma D’Accorso ◽  
Mirta Fascio ◽  
Carlos Gustavo Arabehety ◽  
Alicia M. Seldes
Keyword(s):  
Gas Phase ◽  
Electron Ionization

scholarly journals Pressure Dissociation and the Hydrogen Molecular Ion

1966 ◽  
Vol 134 (2) ◽  
pp. 183-188 ◽  
Author(s):  
M. S. Vardya
Keyword(s):  
Hydrogen Molecular Ion ◽  
Molecular Ion
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