Electron Impact Ionization of Dicyclopentadienyl-Manganese and Cyclopentadienyl-Manganese-Tricarbonyl Compared with Dimanganese-Decacarbonyl: Appearance Energies, Bond Energies and Enthalpies of Formation

2001 ◽  
Vol 7 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Joachim Opitz
Keyword(s):  
Electron Impact ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Enthalpies Of Formation ◽  
Bond Energies ◽  
Dimanganese Decacarbonyl ◽  
Manganese Tricarbonyl

Electron-Impact Ionization of Mandelic Acid and Mandelic Acid Methyl Ester as Prototypes for the C6H5CH(OH)-X System: Ionization and Appearance Energies, Activation Energies and Enthalpies of Formation

2005 ◽  
Vol 11 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Joachim Opitz
Keyword(s):  
Methyl Ester ◽  
Electron Impact ◽  
Mandelic Acid ◽  
Impact Ionization ◽  
Acid Methyl Ester ◽  
Electron Impact Ionization ◽  
Molecular Ions ◽  
Enthalpies Of Formation ◽  
Ionization Mass ◽  
Acid Methyl

Electron-impact ionization mass spectra, the decay of metastable ions, ionization and appearance energies and bond energies, as dissociation energies, are reported for mandelic acid (MA) and mandelic acid methyl ester (MAME) . An ionization energy of 8.55 eV was obtained for both compounds. For the formation of C6H5+ ions, appearance energies of 14.25 eV or 14.40 eV were determined for MA or MAME, respectively. On the main fragmentation route from molecular ions to these C6H5+ ions, an activation energy of (1.1±0.1)eV in excess of the calculated total reaction enthalpy was found for the elimination of CO from the prominent C7H7O+ ions to C6H7+ ions, involving the transfer of two H-atoms. The second (minor) fragmentation route via C7H6O+ions resembles the benzaldehyde decomposition pathway and the individual steps were found to be near to their calculated thermochemical reaction enthalpies. Gas-phase enthalpies of formation of (–4.652±0.3 eV) [≡ (–448.8±30) kJ mol−1] for MA and (–4.243±0.3) eV [≡ (–409.4±30) kJ mol−1] for MAME are derived, based on the appearance energy of their C7H7O+ ions at m/z 107 and the formation enthalpy adopted from protonated benzaldehyde. The results are compared with data for benzylalcohol.

scholarly journals Low-energy electron-impact ionization of helium

1998 ◽  
Vol 57 (5) ◽  
pp. R3161-R3164 ◽  
Author(s):  
Igor Bray ◽  
Dmitry V. Fursa ◽  
J. Röder ◽  
H. Ehrhardt
Keyword(s):  
Electron Impact ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron

Electron-impact ionization of atomic ions in the W isonuclear sequence

2005 ◽  
Vol 72 (5) ◽  
Author(s):  
S. D. Loch ◽  
J. A. Ludlow ◽  
M. S. Pindzola ◽  
A. D. Whiteford ◽  
D. C. Griffin
Keyword(s):  
Electron Impact ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Atomic Ions

Isotope effects in the electron impact ionization of H2/D2, H2O/D2O, and C6H6/C6D6 near threshold

2002 ◽  
Vol 116 (6) ◽  
pp. 2456-2463 ◽  
Author(s):  
G. Hanel ◽  
B. Gstir ◽  
T. Fiegele ◽  
F. Hagelberg ◽  
K. Becker ◽  
...  
Keyword(s):  
Electron Impact ◽  
Impact Ionization ◽  
Isotope Effects ◽  
Electron Impact Ionization ◽  
Near Threshold
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