Negative Ionen durch Elektronenstoß aus organischen Nitroverbindungen, Äthylnitrit und Äthylnitrat

1967 ◽  
Vol 22 (5) ◽  
pp. 700-704
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Molecular Ions ◽  
Ion Source ◽  
Negative Ion ◽  
Electron Affinities ◽  
Low Intensity ◽  
Ion Molecule Reactions ◽  
Fragment Ions ◽  
Product Ions

Negative ion formation by electron impact has been studied in nitromethane, nitroethane, nitrobenzene, tetranitromethane, ethylnitrite and ethylnitrate. Appearance potentials, ionization efficiency curves and kinetic energies of negative ions were measured by using a Fox ion source. The electron affinities of C2H5O and of C (NO2)3 are discussed as well as the energetics of processes which yield NO2-. The electron capture in nitrobenzene and tetranitromethane leads to molecular ions [C6H5NO2~ in high, C (NO2)4 in very low intensity] besides many fragment ions. A number of product ions from negative ion-molecule reactions has also been found.

Negative Ionen durch Elektronenstoß an einigen organischen Schwefelverbindungen

1966 ◽  
Vol 21 (8) ◽  
pp. 1251-1259 ◽  
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Electron Impact ◽  
Electron Capture ◽  
Chemical Reactions ◽  
Hydrogen Sulphide ◽  
Negative Ions ◽  
Ion Source ◽  
Ionization Efficiency ◽  
Dissociative Electron Capture ◽  
Negative Ion ◽  
Electron Affinities

Negative ion formation by electron impact has been studied in hydrogen sulphide, methylmercaptan, phenylmercaptan, benzylmercaptan, allylmercaptan, dimethylthioether, dimethyldisulphide and diallyldisulpbide. Appearance potentials, ionization efficiency curves and the kinetic energies of negative ions were measured by using a Fox ion source. The energies of various dissociative electron capture processses are discussed and electron affinities of some radicals of the types RS and RS2 are derived. Two chemical reactions of the CH2S- ion with dimethyldisulphide have been detected.

Die Bildung negativer Ionen aus SiCl4 und organischen Siliciumchloriden durch Elektronenstoß

1968 ◽  
Vol 23 (8) ◽  
pp. 1122-1127 ◽  
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Kinetic Energy ◽  
Electron Impact ◽  
Electron Affinity ◽  
Free Electron ◽  
Negative Ions ◽  
Molecular Ions ◽  
Ion Source ◽  
Silicon Compounds ◽  
Fragment Ions ◽  
Zero Kinetic Energy

Appearance potentials and ionization efficiency curves of negative ions formed in SiCl4, CH3SiCl3, (CH3)2SiCl2, (CH3)3) 3SiCl, C2H3SiCl3, and C6H5SiCl3 by electron impact have been measured by using a Fox ion source. Negative molecular ions were observed in SiCl4, C2H3SiCl3 and C6H5SiCl3 besides several fragment ions. The electron affinity of the SiCl3 radical was found to be about equal to the electron affinity of the chlorine atom. The electron affinity of SiCl2 is shown to be higher than 2.5 eV.Dissociative electron capture processes from SF6– have been found in mixtures of SFe and silicon compounds (such as SF6–+SiCl4 ➝ Cl–+SiCl3+SF6). It is concluded that in these processes the electron in SF6– behaves like a free electron of zero kinetic energy. Various reactions of the O–-ion with the silicon compounds have also been observed.

Mass spectral investigations on selenium compounds. II. The behaviour of meta-and para-substituted benzeneseleninic acids and of meta-nitrophenyl selenocyanate under electron impact

1982 ◽  
Vol 35 (7) ◽  
pp. 1365 ◽  
Author(s):  
A Benedetti ◽  
C Preti ◽  
L Tassi ◽  
G Tosi
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrum ◽  
Electron Impact ◽  
Molecular Ions ◽  
Selenium Compounds ◽  
Molecular Ion ◽  
Mass Spectral ◽  
Low Intensity ◽  
Fragment Ions

Substituted benzeneseleninic acids of the type XC6H4SeO2H (X = m-Cl, p-Cl, m-Br, p-Br, p-Me, m-NO2, p-NO2) have been investigated by mass spectrometry. The fragmentation modes and the fragment ions are discussed and compared with those obtained from the mass spectrum of m-nitro-phenyl selenocyanate, O2NC6H4SeCN. Generally, as regards the acids, besides very weak peaks due to the molecular ions, a number of peaks at higher mass numbers and of greater intensity is observed; these peaks are in multiplets typical of the presence of two selenium atoms, and they correspond to the disubstituted diphenyl diselenides of the type XC6H4SeSeC6H4X. m-Nitrophenyl selenocyanate shows an intense molecular ion peak and the relative fragmentation, while the peak due to the diselenide is of very low intensity.

scholarly journals Electron-impact ionization and ionic fragmentation of O2 from threshold to 120 eV energy range

2021 ◽  
pp. 2150104
Author(s):  
R. A. Lomsadze ◽  
M. R. Gochitashvili ◽  
R. Ya. Kezerashvili ◽  
M. Schulz
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Theoretical Data ◽  
Electron Impact Ionization ◽  
Ion Source ◽  
Fragment Ions ◽  
Collision Chamber ◽  
Product Ions ◽  
Dissociative Processes

We study the electron-impact induced ionization of O2 from threshold to 120 eV using the electron spectroscopy method. Our approach is simple in concept and embodies the ion source with a collision chamber and a mass spectrometer with a quadruple filter as a selector for the product ions. The combination of these two devices makes it possible to unequivocally collect all energetic fragment ions formed in ionization and dissociative processes and to detect them with known efficiency. The ion source allows varying and tuning the electron-impact ionization energy and the target-gas pressure. We demonstrate that for obtaining reliable results of cross-sections for inelastic processes and determining mechanisms for the formation of O[Formula: see text]([Formula: see text]) ions, it is crucial to control the electron-impact energy for production of ion and the pressure in the ion source. A comparison of our results with other experimental and theoretical data shows good agreement and proves the validity of our approach.

THE IONIZATION AND DISSOCIATION OF SOME HALOGEN MOLECULES BY ELECTRON IMPACT

1960 ◽  
Vol 38 (3) ◽  
pp. 407-420 ◽  
Author(s):  
D. C. Frost ◽  
C. A. McDowell
Keyword(s):  
Electron Impact ◽  
Excited States ◽  
Electronic Structures ◽  
Negative Ions ◽  
Molecular Ions ◽  
Negative Ion ◽  
Iodine Monochloride ◽  
Monoenergetic Electron ◽  
Iodine Monobromide ◽  
Ionization Processes

The ionization and dissociation of chlorine, bromine, iodine, iodine monochloride, and iodine monobromide by electron impact have been studied in a mass spectrometer which uses a monoenergetic electron source. Many ionization potentials have been observed for these molecules which, of course, refer to the formation of the parent molecular ions in different excited states. These experimental results are discussed in terms of simple molecular orbital theories of the electronic structures of the different halogen molecules.Electron-induced dissociative ionization processes for the different substances have also been studied. Where possible, appearance potentials of both the positive and negative ions have been determined. These results have been used to construct potential energy diagrams illustrating the origin of some of the negative ion and dissociation processes observed.

Electron impact studies. XCIII. The reactions of negative ions from 3- and 4-nitrophthalic anhydrides

1975 ◽  
Vol 28 (3) ◽  
pp. 563 ◽  
Author(s):  
JH Bowie ◽  
BD Williams
Keyword(s):  
Electron Impact ◽  
Phthalic Anhydride ◽  
Cyclotron Resonance ◽  
Mass Spectra ◽  
Negative Ions ◽  
Negative Ion ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Ion Molecule Reactions ◽  
Positive Ions

Possible structures for some rearrangement ions in the negative ion mass spectra of 3- and 4-nitro- phthalic anhydride are suggested from an examination of the + E spectra obtained by the conversion of the negative ions to positive ions by charge-stripping reactions. The reactivities of the non-decomposing negative ions have been investigated by observation of their ion-molecule reactions with the neutral anhydride in the cell of an ion cyclotron resonance spectrometer.

Negative-Ion Implantation

1994 ◽  
Vol 354 ◽  
Author(s):  
Junzo Ishikawa
Keyword(s):  
Ion Implantation ◽  
Negative Ions ◽  
Ion Source ◽  
Negative Ion ◽  
Rf Plasma ◽  
Ion Currents ◽  
Promising Technique ◽  
Surface Charging ◽  
Silicon Carbon ◽  
A Charge

AbstractNegative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected without a charge neutralizer in these fabrication processes. Scatter-less negative-ion implantation into powders is also possible. For this purpose an rf-plasma-sputter type heavy negative-ion source was developed, which can deliver several milliamperes of various kinds of negative ion currents such as boron, phosphor, silicon, carbon, copper, oxygen, etc. A medium current negative-ion implanter with a small version of this type of ion source has been developed.

Comparison of Five Ionization Methods for Producing Mass Spectra of Typical Organophosphorus Pesticides

1978 ◽  
Vol 32 (4) ◽  
pp. 388-399 ◽  
Author(s):  
Kenneth L. Busch ◽  
Maurice M. Bursey ◽  
J. Ronald Hass ◽  
G. Wayne Sovocool
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Organophosphorus Pesticides ◽  
Large Fraction ◽  
Negative Ion ◽  
Oxygen Mixture ◽  
Ion Molecule Reactions ◽  
And Migration ◽  
Positive Chemical Ionization

Positive ion mass spectra obtained by conventional electron impact and by methane chemical ionization were compared with the negative ion mass spectra of 16 typical organophosphorus pesticides using methane, a methane-oxygen mixture, and oxygen as enhancement/reagent gases. In the negative ion spectra, phosphate and phenate anions typically carry a large fraction of the ion current. Displacement of chlorine by oxygen is noted in some cases, and migration of aryl groups from oxygen to sulfur is occasionally noted. Ion-molecule reactions between two species derived from sample molecules have been observed. The sensitivity of the negative ion techniques for the pesticides examined is greater than conventional electron impact or methane positive chemical ionization techniques, and can be up to 800 times more sensitive for some compounds.

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