Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (5)
  • 1
    Electronic Resource
    Electronic Resource
    Metastable ion study of organosilicon compounds VIFor Part V, see Ref. 1. - triethoxymethylsilane and tetraethoxysilane (1993)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 28 (1993), S. 412-420 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fragmentations of triethoxymethylsilane ((C2H5O)3SiCH3 (1)) and tetraethoxysilane ((C2H5O)4Si (3)) induced by electron impact were investigated by mass-analysed ion kinetic energy (MIKE) spectrometry and a deuterium-labelling study. These molecular ions begin to fragment by the loss of methyl, ethyl and/or ethoxy radicals. Almost complete scrambling of methylene hydrogen takes place in these resultant intermediate ions, prior to the elimination of acetaldehyde molecule. The fragmentations of [1]+· and [3]+· were compared with those of the corresponding carbon analogues, 1,1,1-triethoxyethane ((C2H5O)3CCH3 (2)) and tetraethoxymethane ((C2H5O)4C (3)), respectively.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210280425
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Metastable ion study of organosilicon compounds, part VII.1 Losses of C2H4 and CH4 from the metastable dimethylsilyl ion [(CH3)2Si+H] (1993)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 7 (1993), S. 867-869 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The spontaneous unimolecular dissociative reactions of dimethylsilyl cations (CH3)2Si+H (1+; m/z 59) have been investigated by mass-analyzed ion kinetic energy (MIKE) spectrometry and deuterium-labelling studies. Excepting the losses of H and H2, the ions 1+ mainly eliminate C2H4 and CH4 to produce product ions at m/z 31 and 43, respectively. Almost complete hydrogen scrambling occurs prior to the C2H4 loss, but only a small degree of scrambling occurs in the CH4 loss. Predominantly, the hydrogen atom bound to Si participates in the latter reaction, contrary to the previously reported mechanism.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290071002
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Metastable ion study of organosilicon compounds. Part VFor Part IV, see Ref. 1. - tetramethoxysilane and trimethoxymethylsilane (1992)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 27 (1992), S. 702-708 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fragmentations of tetramethoxysilane ((CH3O)4Si (1)) and trimethoxymethylsilane ((CH3O)3SiCH3 (3)) induced by electron impact were investigated by mass-analysed ion kinetic energy (MIKE) spectrometry and a deuterium-labelling study. These molecular ions begin to fragment by the loss of CH3 or CH3O. These fragmentations are followed by the loss of an aldehyde molecule (H2CO), as commonly observed in the mass spectra of alkoxysilanes. Almost complete scrambling of the methoxy hydrogens takes place in the metastable molecular ion, [1]+·, prior to the decomposition. On the other hand, a moderate extent of scrambling of the hydrogens takes place in [3]+·. The fragmentations of [1]+· and [3]+· were compared with those of the corresponding carbon analogues, tetramethoxymethane ((CH3O)4C (2)) and 1,1,1-trimethoxyethane ((CH3O)3CCH3 (4)), respectively.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210270611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Metastable ion study of organosilicon compounds. Part III - trimethoxyphenylsilane (1990)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 25 (1990), S. 441-445 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The unimolecular decomposition of trimethoxyphenylsilane (1) was investigated by mass-analysed ion kinetic energy (MIKE) spectrometry, deuterium-labelling studies and from high resolution data. The characteristic fragmentations of metastable molecular ion of 1 were losses of C6H6 and C7H7· with rearrangements. Almost complete H/D scrambling occurred in the molecular ion prior to these decompositions. The other important fragmentation routes corresponded to expulsions of CH3O· and C6H5·. These fragmentations were followed by consecutive elimination of an H2CO molecule, as commonly observed in the mass spectra of alkoxysilanes. In these fragmentation processes, H/D scrambling increased as the internal energy of the molecular ion was lowered. The fragmentations of 1 were compared with those of its carbon analogue, α,α,α-trimethoxytoluene.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210250902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Metastable ion study of organosilicon compounds part II - hexamethyldisiloxane (1990)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 25 (1990), S. 39-43 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Unimolecular reactions of the metastable silicenium ion (CH3)3SiOSi(CH3)2 + generated by dissociative ionization of bexamethyldisiloxane were investigated by mass-analysed ion kinetic energy (PUKE) Spectrometry. The characteristic fragmentations observed were losses of CH4 and (CH3)2Si=O molecules. Complete scrambling of all methyl groups prior to these reactions was found by investigating the MIKE spectra of deuterium labelled analogues (CD3)3SiOSi(CH3)2+ and (CH3)3SiOSi(CD3)3+. The loss of methane was accompanied by a large kinetic energy release (T0.5 = 482 meV). The MIKE spectra of silicenium ions were compared with those of their carbon analogues. The most predominant reaction of metastable (CH3)3COC(CH3)3+ ion was the loss of CH2=C(C H3)2 leading to protonated acetone. Significant differences between the ion fragmention characteristics of silicon and carbon compounds were found.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210250109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...