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  • 1
    Electronic Resource
    Electronic Resource
    Experimental setup for the measurement of persistent current in a GaAs/GaAlAs single loop
    Amsterdam : Elsevier
    Microelectronic Engineering 9 (1989), S. 349-351 
    Details
    ISSN: 0167-9317
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0167-9317(89)90076-2
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Halogenation and amination dual properties of haloamines in Raschig environment: A chlorine transfer reaction between chloramine and 3-azabicyclo[3,3,0]octane (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 29 (1997), S. 89-98 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chlorine transfer reaction between 3-azabicyclo[3,3,0]octane “AZA” and chloramine was studied over pH 8-13 in order to follow both the amination and halogenation properties of NH2Cl. The results show the existence of two competitive reactions which lead to the simultaneous formation of N-amino- and N-chloro- 3-azabicyclo[3,3,0]octane by bimolecular kinetics. The halogenation reaction is reversible and the chlorine derivative obtained, which is thermolabile and unstable in the pure state, was identified by electrospray mass spectrometry. These phenomena were quantified by a reaction between neutral species according to an apparent SN2-type mechanism for the amination process and a ionic mechanism involving a reaction between chloramine and protonated amine for the halogenation process. Amination occurs only in strongly basic solutions (pH ≥ 13) while chlorination occurs at lower pH's (pH ≤ 8). At intermediate pH's, a mixture of these two compounds is obtained. The relative proportions of the products are a function of intrinsic rate constants, pH and pKa of the reactants. The rate constants and thermodynamic activation parameters are the following: k1 = 45.5 × 10-3 M-1 s-1; ΔH10# = 59.8 kJ mol-1; ΔS10# = - 86.5 J mol-1 K-1 for amination; k2 = 114 × 10-3 M-1 s-1; ΔH20# = 63.9 kJ mol-1; and ΔS20# = - 48.3 J mol-1 K-1 for chlorination. The ability of an interaction corresponding to a specific(NH3Cl+/RR′NH) or general (NH2Cl/RR′NH) acid catalysis has been also discussed. © 1997 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Kinetics of dehydrohalogenation of N-chloro-3-azabicyclo[3,3,0]octane in alkaline medium. NMR and ES/MS evidence of the dimerization of 3-azabicyclo[3,3,0]oct-2-ene (1998)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 30 (1998), S. 129-136 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The formation of 3-azabicyclo[3,3,0]oct-2-ene in the course of the synthesis of N-amino-3-azabicyclo[3,3,0]octane using the Raschig process results from the following two consecutive reactions: chlorine transfer between the monochloramine and the 3-azabicyclo[3,3,0]octane followed by a dehydrohalogenation of the substituted haloamine. The kinetics of the reaction were studied by HPLC and UV as a function of temperature (15 to 44°C), and the concentrations of NaOH (0.1 to 1 M) and the chlorinated derivative (1 to 4×10-3 M). The reaction is bimolecular (k=103×10-6 M-1 s-1; ΔH0#=89 kJ mol-1; and ΔS0#=-33.6 J mol-1 K-1) and has an E2 mechanism. The spectral data of 3-azabicyclo[3,3,0]oct-2-ene were determined. IR, NMR, and ES/MS analysis show dimerization of the water-soluble monomer into a white insoluble dimer. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 129-136, 1998.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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