Electron impact studies. XVIII. Mass spectra of pyridazines, phthalazines, and related compounds

1967 ◽  
Vol 20 (12) ◽  
pp. 2677 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
PF Donaghue ◽  
JA Halleday ◽  
HJ Rodda

The mass spectra of substituted pyridazines, phthalazines, and related compounds are reported and discussed. Molecular ions are a prominent feature of all the spectra, and fragmentation modes may be usefully correlated with both the type of heterocycle and its substitution pattern. Fragmentation patterns have been substantiated by extensive high resolution studies and appropriate metastable ions.

1967 ◽  
Vol 20 (4) ◽  
pp. 689 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
P Jakobsen ◽  
S Lawesson ◽  
G Schroll

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.


1971 ◽  
Vol 54 (1) ◽  
pp. 178-186
Author(s):  
O Hutzinger ◽  
W D Jamieson ◽  
S Safe

Abstract Fragmentation patterns on electron impact of 15 chlorinated aromatic fungicides were investigated. In most cases strong molecular ions were obtained and the peak clusters due to the 35Cl and 37Cl isotopes and the number of chlorine atoms in the molecule were highly characteristic. Many of the polychlorinated fungicides give ions (e.g., C6Cl4, C6Cl3, C6Cl2, C6Cl, and C6 (CN)2) whose structures can be best represented as acyclic polyunsaturated moieties.


1976 ◽  
Vol 59 (3) ◽  
pp. 622-632 ◽  
Author(s):  
Francis I Onuska ◽  
Michael E Comba

Abstract Electron impact mass spectra of 8 sodium alkyl and dialkyl dithiocarbamate salts are reported with the spectra of 2 dithiocarbamate zinc salts and N′,N′-dimetliyl-N,N-dimethylthiocarbamylsulfenamide. The investigated compounds all gave molecular ions, and generalized descriptions of their fragmentation behavior are presented.


1967 ◽  
Vol 20 (8) ◽  
pp. 1601 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
GE Lewis

The mass spectra of 15 aromatic azoxy compounds are reported and discussed. The spectra exhibit pronounced molecular ions, and fragmentation modes which are produced by both simple cleavage and complex skeletal reorganization processes.


1999 ◽  
Vol 23 (9) ◽  
pp. 584-585
Author(s):  
Aifheli C. Gelebe ◽  
Perry T. Kaye

Fragmentation patterns in the electron-impact (El) mass spectra of benzoxathiepine derivatives are elucidated using a combination of high-resolution and comparative low-resolution mass spectrometric analysis.


1969 ◽  
Vol 22 (1) ◽  
pp. 153 ◽  
Author(s):  
JH Bowie ◽  
F Duus ◽  
S Lawesson ◽  
FCV Larsson ◽  
J+ Madsen

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.


1976 ◽  
Vol 29 (12) ◽  
pp. 2731
Author(s):  
E Njau

The mass spectra of 4a-methyl-4,4a-dihydrophenanthren-2(3H)-one and closely related phenanthrenones have been studied. The suggested fragmentation processes, substantiated by high-resolution mass measurements and appropriate metastable peaks, are shown to be characteristic of compounds with the same hydro-oxo-phenanthrene chromophore. 2-Cinnamylidene-6-methyl-cyclohexanone possessing a similar chromophore is also shown to exhibit a comparable fragmentation pattern.


1975 ◽  
Vol 28 (5) ◽  
pp. 1011 ◽  
Author(s):  
JH Bowie ◽  
BJ Stapleton

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.


1967 ◽  
Vol 20 (8) ◽  
pp. 1613 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
S Lawesson ◽  
G Schroll

The mass spectra of 37 imidazoles are reported and discussed. The spectra exhibit pronounced molecular ions and characteristic fragmentation patterns. The fragmentation modes have been substantiated by deuterium labelling, exact mass measurements, and appropriate metastable ions. Skeletal rearrangement fragments are rare in these spectra; consequently mass spectrometry is useful for structure elucidation of imidazoles.


1966 ◽  
Vol 19 (9) ◽  
pp. 1627 ◽  
Author(s):  
JH Bowie ◽  
DW Cameron

The mass spectra of 11 quercetagetin derivatives are reported and discussed. The spectra are generally simple and amenable to analysis. 4 number of fragmentation processes have been substantiated by exact mass measurements, appropriate metastable ions, and deuterium labelling.


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