Mass spectra of spermatheridine alkaloids. The structure of moschatoline

1967 ◽  
Vol 20 (7) ◽  
pp. 1403 ◽  
Author(s):  
IRC Bick ◽  
JH Bowie ◽  
GK Douglas
Keyword(s):  
Mass Spectra ◽  
Mass Measurements ◽  
Exact Mass ◽  
Deuterium Labelling ◽  
System A ◽  
Tetracyclic System ◽  
Characteristic Fragmentation ◽  
Fragmentation Processes

The mass spectra of a series of alkaloids of the spermatheridine group, together with those of their alkoxy derivatives, are reported and discussed. The characteristic fragmentation processes, substantiated by appropriate metastable peaks, exact mass measurements, and in some cases by deuterium labelling, facilitate the location of substituents in the tetracyclic system. A structure for moschatoline is deduced from a consideration of the mass spectra of its derivatives.

Electron impact studies. I. High resolution mass spectra of some unsaturated cyclic ketones

1966 ◽  
Vol 19 (9) ◽  
pp. 1619 ◽  
Author(s):  
JH Bowie
Keyword(s):  
High Resolution ◽  
Electron Impact ◽  
Mass Spectra ◽  
Cyclic Ketones ◽  
Mass Measurements ◽  
Exact Mass ◽  
Characteristic Fragmentation ◽  
Fragmentation Processes ◽  
Resolution Mass

The mass spectra of some 2-cyclohexen-1-ones, tetralones, and indanones have been investigated. The characteristic fragmentation processes, substantiated by appropriate metastable peaks, exact mass measurements, and in some cases by deuterium labelling studies, greatly facilitate the determination of both the type of system and the position of substituents on that system.

Electron impact studies. II. Mass spectra of quercetagetin derivatives

1966 ◽  
Vol 19 (9) ◽  
pp. 1627 ◽  
Author(s):  
JH Bowie ◽  
DW Cameron
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Mass Measurements ◽  
Exact Mass ◽  
Deuterium Labelling ◽  
Impact Studies ◽  
Metastable Ions ◽  
Fragmentation Processes

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.

Electron impact studies. XII. Mass spectra of substituted imidazoles

1967 ◽  
Vol 20 (8) ◽  
pp. 1613 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
S Lawesson ◽  
G Schroll
Keyword(s):  
Mass Spectrometry ◽  
Structure Elucidation ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Skeletal Rearrangement ◽  
Mass Measurements ◽  
Exact Mass ◽  
Metastable Ions ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

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.

Mass spectra of α-diketones. I. Non-enolized α-diketones

1968 ◽  
Vol 21 (5) ◽  
pp. 1247 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
GE Gream ◽  
MH Laffer
Keyword(s):  
Mass Spectra ◽  
Molecular Ions ◽  
Ring Size ◽  
Mass Measurements ◽  
Exact Mass ◽  
Deuterium Labelling ◽  
Mclafferty Rearrangement ◽  
Metastable Ions ◽  
Fragmentation Patterns

The mass spectra of a series of a-diketones are reported and discussed. Fragmentation patterns have been substantiated by exact mass measurements, metastable ions, and in two cases, by deuterium labelling studies. The McLafferty rearrangement is not observed in the spectra of aliphatic α-diketones; fragmentation proceeds by α-cleavage. The fragmentation modes of those cyclic α-diketones studied depend largely on the ring size. Molecular ions are observed in all spectra.

Some Aspects of the Mass Spectra of.N-Nitrosamines

1971 ◽  
Vol 49 (9) ◽  
pp. 1367-1371 ◽  
Author(s):  
J. W. ApSimon ◽  
J. D. Cooney
Keyword(s):  
Mass Spectra ◽  
Accurate Mass ◽  
Mass Measurements ◽  
Molecular Ion ◽  
Accurate Mass Measurements ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

The mass spectra of seven cyclic N-nitrosamines were examined for characteristic fragmentation patterns. Accurate mass measurements on three of the compounds indicated that the M-17 and M-30 peaks resulted from molecular ion losses of •OH and •NO respectively. The loss of • OH was rationalized in terms of a McLafferty-type rearrangement.

Electron impact studies of 4a-Methyl-4,4a-dihydrophenanthren-2(3H)-one and related phenanthrones

1976 ◽  
Vol 29 (12) ◽  
pp. 2731
Author(s):  
E Njau
Keyword(s):  
High Resolution ◽  
Electron Impact ◽  
Mass Spectra ◽  
Fragmentation Pattern ◽  
Mass Measurements ◽  
Impact Studies ◽  
High Resolution Mass ◽  
Fragmentation Processes ◽  
Resolution Mass

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.

Differentiation of the Isomeric o-(m- and p-) Nitro-(Chloro- and Bromo-)Benzyl-2,4-(and 2,1-) Disubstituted 2-Thiocytosinium Halides by Electron Impact Ionisation and Fast Atom Bombardment Mass Spectrometry

2009 ◽  
Vol 15 (4) ◽  
pp. 497-506 ◽  
Author(s):  
Tomasz Pospieszny ◽  
Elżbieta Wyrzykiewicz
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Collision Induced Dissociation ◽  
Mass Measurements ◽  
Fragmentation Pathways ◽  
Mass Spectral ◽  
Fragment Ions ◽  
Accurate Mass Measurements ◽  
Impact Ionisation

Electron ionisation (EI) and fast atom bombardment (FAB) mass spectral fragmentations of nine 2,4-(and 2,1-) disubstituted o-( m- and p-)nitro-(chloro- and bromo-)-2-thiocytosinium halides are investigated. Fragmentation pathways, whose elucidation is assisted by accurate mass measurements and metastable transitions [EI-mass spectrometry (MS)], as well as FAB/collision-induced dissociation (CID) mass spectra measurements are discussed. The correlations between the abundances of the (C11H10N4SO2)+1–3; (C11H10N3SCl)+4–6 and (C11H10N3SBr)+7–9 ions and the selected fragment ions (EI-MS), as well as (C18H16N5SO4)+1–3; (C18H16N3SCl2)+4–6 and (C18H16N3SBr2) + 7–9 ions and the selected ions (C7H6NO2)+1–3; (C7H6Cl)+ 4–6; (C7H6Br)+ 7–9 (FAB-MS) are discussed. The data obtained can be used for distinguishing isomers.

Synthesis and Vibrational and Mass Spectra of Ph3SnO2PMe2, Ph3SnO2PMePh and Ph3SnO2PPh2

1994 ◽  
Vol 49 (10) ◽  
pp. 1319-1323 ◽  
Author(s):  
Abdel-Fattah Shihada
Keyword(s):  
Raman Spectra ◽  
Mass Spectra ◽  
Ir And Raman Spectra ◽  
Phenyl Radicals ◽  
Ir And Raman ◽  
Fragmentation Processes ◽  
Polymeric Structures

AbstractThe reactions of (Ph3Sn)2O with PhMePOCl and with Ph2POCl lead to Ph3SnO2PMePh and Ph(SnO2PPh2, respectively. Ph3SnO2PMe2 has been prepared from the reaction of (Ph3Sn)2O and Me2PO2H in toluene. The IR and Raman spectra of Ph3SnO2PMe2, Ph3(SnO2PMePh and Ph3SnO2PPh2 are found to be consistent with polymeric structures with pentacoordinated tin atoms. The EI mass spectra indicate that the principal fragmentation processes of Ph3SnO2PRR′ (RR′ = Me2, MePh, Ph2) appear to occur by loss of phenyl radicals from tin and by elimination of the entire diorganophosphinate group.

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