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  • 1
    Electronic Resource
    Electronic Resource
    Mass spectrometric studies of sulfur compounds. Some 1-(5-ethyl-2-thienyl)-1-thiaalkanes (1979)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 6 (1979), S. 260-265 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fragmentation studies of the mass spectra of 15 high purity compounds of the 1-(5-ethyl-2-thienyl)-1-thiaalkane series are presented. The molecular weight range covered is from 158 to 284. These substances are of importance to those utilizing fossil fuels which contain them and also to those studying natural products. The molecular ion intensities are moderately strong and easy to verify due to the presence of two sulfur atoms in the molecule. Prominent ions occur in all spectra at m/z 144 and 129. A total of six different ion species are base peaks for the compounds reported, including alkyl and alkenyl ions. The methyl and ethyl compounds are exceptions to the correlations developed in this work and are discussed in detail. Metastable and low ionization voltage data are presented in support of the suggested mechanisms of fragmentation. Those using only three to four peaks in selected ion monitoring should anticipate experiencing difficulties with positive identification of these types of molecules due to the plethora of alkylions. An integration of the correlations developed with those of other sulfur containing moieties is presented.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200060607
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  • 2
    Electronic Resource
    Electronic Resource
    The mass spectrum of 1-(2-thienyl) hexane-1-13C (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 191-198 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectrum of 1-(2-thienyl) hexane-1-13C is reported. The principal fragmentation routes ofthe parent ion are delineated. Beta cleavage of the alkyl chain predominates, and the label retention indicates that the alpha carbon atom remains with the charged ring moiety. A substantial part of the m/e 97 ion undergoes a ring expansion to a six membered ring. A small amount of alpha cleavage of the alkyl chain occurs with the expected loss of the label. Further fragmentation of the ions from initial alpha or beta cleavage produces similar fragment ions. It is noted that many of the neutral particles lost in the formation of the fragment ions are typical of those encountered in the alkylbenzenes or other aromatic ion systems.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010202
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  • 3
    Electronic Resource
    Electronic Resource
    Decomposition of 1-(2-thienyl)alkylalkanones under electron-impactIn part presented at the Southwest regional meeting of the American Chemical Society, meeting at Dallas, Texas, 6th to 8th December, 1962. (1969)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1969), S. 1005-1015 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The major fragmentation paths of the 1-(2-thienyl)alkylalkanones ionized by electron impact are delineated by means of isotopically labeled molecules, metastable ion peaks and low ionization voltage data. A prominent process is cleavage of the bond beta to the carbonyl group with the concurrent rearrangement of a hydrogen atom. Another important process is cleavage alpha to the carbonyl group to produce the thienoylium ion analogous to the benzoylium ion. As expected, the data show that increasing the chain length by two methylene groups increases the total ion current. The bulk of this increase is found in the increased ion current of the rearrangement ion with the remainder being associated with alkyl fragments and oxygenated ion species.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210021009
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Mass fragmentographic studies of sulfur compounds: The thienylthiaalkanes (1974)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1974), S. 297-304 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fragmentation studies of the mass spectra of 24 high purity compounds of importance in a study of fossil fuels are described. The substances include eleven 1-(2-thienyl)-1-thia-, six1-(2-thienyl)-3-thia, and seven1-(2-thienyl)-4-thiaalkanes in the molecular weight range 158 to 270. Rearrangement peaks are prominent in all spectra and form the base peaks for the 1-thia- and 4-thia- compounds. The 3-thia- compounds are somewhat perverse in exhibiting weaker rearrangement peaks, and large ion intensities, including base peaks, at masses typical of alkyl fragments, alkenyl fragments, or ions more characteristic of the thiaalkanes (aliphatic sulfides). The major fragment ions are discussed and their use in differentiating subclasses is described. Low ionization voltage data is presented in support of suggested mechanisms of fragmentation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200010502
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