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  • Fe(acac)3  (1)
  • Isobutyl carbenium ion  (1)
  • 1
    Electronic Resource
    Electronic Resource
    13C solid state NMR evidence for the existence of isobutyl carbenium ion in the reaction of isobutyl alcohol dehydration in H-ZSM-5 zeolite (1993)
    Springer
    Catalysis letters 19 (1993), S. 153-158 
    Details
    ISSN: 1572-879X
    Keywords: Isobutyl carbenium ion ; carbon scrambling ; H-ZSM-5 zeolite ; 2DJ-resolved13C solid state NMR ; dehydration of isobutyl alcohol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Using two-dimensionalJ-resolved and CP/MAS13C NMR, the pathway for the transfer of the13C label from the CH2 group of isobutyl alcohol into the hydrocarbon skeleton of butene oligomers has been elucidated in the course of isobutyl alcohol dehydration inside H-ZSM-5 zeolite. First, the label is transferred selectively into the CH2 group of the isobutyl silyl ether reaction intermediate (IBSE), and then into the CH and CH3 groups of the isobutyl fragment (-CH2CH(CH3)2) of IBSE and/or butene oligomers. Finally, it is scrambled over the carbon skeleton of the oligomers. The obtained data suggest that isobutyl carbenium ion is formed as a reaction intermediate or transition state during the transformation of isobutyl silyl ether into butene oligomers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00771750
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  • 2
    Electronic Resource
    Electronic Resource
    Spin delocalization from paramagnetic metal complexes [Cr(acac)3 and Fe(acac)3] to saturated hydrocarbons in CHCl3 and CCl4 solutions (1986)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 24 (1986), S. 705-708 
    Details
    ISSN: 0749-1581
    Keywords: Paramagnetic 13C NMR shifts ; Cr(acac)3 ; Fe(acac)3 ; saturated hydrocarbons ; hex-1-ene ; contact charge transfer ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Paramagnetic 13C NMR shifts induced by tris(acetylacetonato)chromium(III) [Cr(acac)3] and tris(acetylacetonato)iron(III) [Fe(acac)3] in various saturated hydrocarbons were determined for the first time using a special technique.The observed shifts, Δδspec, are the result of partial delocalization of unpaired electrons from the paramagnetic complexes on the alkanes. The value of Δδspec depends strongly on the position of a carbon atom in the hydrocarbon molecule, and tends to decrease on passing from primary to quaternary carbon atoms. The observed spin transfer seems to reflect the ‘contact charge transfer.’ The Δδspec shifts in the unsaturated hex-1-ene only slightly exceed those in alkanes.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260240815
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