Electron-impact studies—LV: Skeletal rearrangement and hydrogen scrambling processes in the positive and negative-ion mass spectra of phenyl derivatives of elements of group IV and V

1970 ◽  
Vol 3 (7) ◽  
pp. 933-940 ◽  
Author(s):  
J. H. Bowie ◽  
B. Nussey
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Group Iv ◽  
Negative Ion ◽  
Skeletal Rearrangement ◽  
Impact Studies ◽  
Derivatives Of ◽  
Hydrogen Scrambling

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. VI. Mass spectra of esters and thioesters. Skeletal rearrangement on electron impact

1967 ◽  
Vol 20 (4) ◽  
pp. 689 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
P Jakobsen ◽  
S Lawesson ◽  
G Schroll
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Resolution ◽  
Electron Impact ◽  
Mass Spectra ◽  
Skeletal Rearrangement ◽  
Unsaturated Esters ◽  
Impact Studies ◽  
Unsaturated Alcohols ◽  
Metastable Ions

The mass spectra of representative series of simple alkyl acetoacetates, alkyl acetothioacetates, and some unsaturated esters derived from unsaturated alcohols or phenols are reported and discussed. The fragmentation schemes have been established by high resolution measurements, appropriate metastable ions, and by deuterium and 18O labelling. Many of the spectra show significant skeletal rearrangement fragments arising from either loss of carbon monoxide or carbon dioxide.

Electron impact studies. XXXII. Negative-ion mass spectra of aromatic compounds containing the =N-O- substituent

1968 ◽  
Vol 21 (8) ◽  
pp. 2031 ◽  
Author(s):  
JH Bowie ◽  
SO Lawesson ◽  
BS Larse ◽  
GE Lewis ◽  
G Schroll
Keyword(s):  
Electron Impact ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Negative Ion ◽  
Skeletal Rearrangement ◽  
Marked Contrast ◽  
Azoxy Compounds ◽  
Positive Ion ◽  
Fragmentation Processes

The negative-ion mass spectra of aromatic azoxy compounds, nitrones, and N-oxides exhibit pronounced molecular ions and simple fragmentation processes. No skeletal-rearrangement fragments are produced upon electron impact, in marked contrast to those exhibited in the positive-ion spectra of these compounds.

Electron impact studies. CVIII. Negative-ion mass spectra of the oxime group

1976 ◽  
Vol 29 (11) ◽  
pp. 2437 ◽  
Author(s):  
JH Bowie ◽  
S Janposri
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Major Product ◽  
Negative Ion ◽  
Oxime Group ◽  
Impact Studies ◽  
Molecular Anions

Molecular anions derived from Ar-CH=NOH systems fragment by the process [MI- → [M-H2O]- to yield pronounced peaks corresponding to [ArCN]-. Molecular anions from Ar(CH2)nC(NOH)Ph (n = 0-2) also eliminate H2O, but the mechanisms are often complex. Possible mechanisms for some of these eliminations are suggested after consideration of the + E spectra of non-decomposing [M?H2O]- ions. A characteristic cyclization/retro process of o-O2NC6H4-CH=CH-C(NOH)R molecular anions produces CHO-CR=N-O- as the major product anion.

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