Electron impact studies. CXI. +E Spectra from negative ions. The retro-Diels-Alder process

1977 ◽  
Vol 30 (3) ◽  
pp. 675 ◽  
Author(s):  
JH Bowie ◽  
AC Ho
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Diels Alder ◽  
Negative Ion ◽  
Impact Studies ◽  
Positive Ion

Abundant peaks produced by retro-Diels-Alder cleavages are observed in the dissociative + E spectrum of a negative ion, whenever such peaks are seen in the corresponding positive-ion spectrum of that compound.

Electron impact studies. CII. +E spectra from negative ions. Flavones and quinones

1976 ◽  
Vol 29 (1) ◽  
pp. 115 ◽  
Author(s):  
JH Bowie ◽  
T Blumenthal
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Electric Sector ◽  
Impact Studies ◽  
Molecular Anions ◽  
Positive Ion

+ E spectra derived from the molecular anions of flavones and quinones are used to illustrate and compare the resolution and sensitivity of spectra obtained by both magnetic and electric sector scan techniques. Some fragmentations are noted which do not occur in the conventional positive-ion spectra of these compounds.

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.

Electron impact studies. XL. Negative-ion mass spectra of organosulphur compounds : Thioglycollic acids and arylsulphinylamines

1969 ◽  
Vol 22 (1) ◽  
pp. 153 ◽  
Author(s):  
JH Bowie ◽  
F Duus ◽  
S Lawesson ◽  
FCV Larsson ◽  
J+ Madsen
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Negative Ion ◽  
Skeletal Rearrangement ◽  
Marked Contrast ◽  
Impact Studies ◽  
Positive Ion ◽  
Hydrogen Rearrangement

The negative-ion mass spectra of thioglycollic esters and S- alkylthioglycollic acids exhibit ions produced by simple cleavage and/or cleavage with hydrogen rearrangement. Similar spectra of arylsulphinylamines show pronounced molecular ions together with simple cleavage fragments. No skeletal-rearrangement fragments are present in the negative-ion spectra, in marked contrast with those observed in the corresponding positive-ion spectra.

Electron impact studies. XCVI. Negative ion mass spectra of naturally occurring compounds. Nitrophenyl esters derived from long-chain acids andalcohols

1975 ◽  
Vol 28 (5) ◽  
pp. 1011 ◽  
Author(s):  
JH Bowie ◽  
BJ Stapleton
Keyword(s):  
Electron Impact ◽  
Analytical Method ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Negative Ion ◽  
Impact Studies ◽  
Naturally Occurring ◽  
Molecular Anions ◽  
Positive Ion ◽  
Long Chain

The positive ion mass spectra of long-chain alcohols and acids are either devoid of molecular ions or contain such species in low abundance. The negative ion spectra of p-nitrophenyl esters of these compounds exhibit pronounced molecular anions, showing the technique to be a useful analytical method for these classes of compounds.

Note on radiationless transitions involving three-body collisions

1936 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
R. A. Smith
Keyword(s):  
Continuous Spectrum ◽  
Negative Ions ◽  
Bound State ◽  
Excess Energy ◽  
Negative Ion ◽  
Positive Ions ◽  
Continuous State ◽  
Direct Formation ◽  
Three Body ◽  
Positive Ion

When an electron makes a transition from a continuous state to a bound state, for example in the case of neutralization of a positive ion or formation of a negative ion, its excess energy must be disposed of in some way. It is usually given off as radiation. In the case of neutralization of positive ions the radiation forms the well-known continuous spectrum. No such spectrum due to the direct formation of negative ions has, however, been observed. This process has been fully discussed in a recent paper by Massey and Smith. It is shown that in this case the spectrum would be difficult to observe.

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