Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 36 (1985), S. 111-113 
    ISSN: 1432-0649
    Keywords: 82.50
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Carbon-13 isotope selectivities and specific decomposition yields in the infrared multiple-photon decomposition of CHF3 and CDF3 were examined as a function of wave number using a CO2 TEA laser. The observed maximum selectivities were 30 for CHF3 and 55 for CDF3. The specific decomposition yields in CDF3 were considerably larger than those in CHF3.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0649
    Keywords: 82.50
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Difluoromethane CH2F2 containing 90–98% 13C was obtained in the selective IRMPD of mixtures of CBr2F2/HI, CCl2F2/HI, and CBrClF2/HI. In CBr2F2/HI mixtures, the intermediate product CHBrF2 resulting from the reaction between the initial decomposition fragment CBrF2 and HI underwent secondary selective IRMPD to form highly 13C-enriched CH2F2 in continuous laser irradiation. The intermediate product in the mixtures of CCl2F2/HI and CBrClF2/HI was found to be CHClF2, but no significant secondary photodecomposition in CBrClF2/HI mixtures occurred owing to the low absorption cross section of CHClF2 at the adopted laser frequencies and fluences. The observed decomposition probabilities and selectivities under different conditions with respect to laser frequency, fluence, and partial pressures of halogenated difluoromethanes and HI suggest that CBr2F2 is one of the better candidates for practical 13C separation by IRMPD.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0649
    Keywords: 82.50 ; 33
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have been studying the practical CO2-laser-induced13C separation by a two-stage IRMPD process. The IRMPD of natural CHClF2 in the presence of Br2 mainly produced CBr2F2, which was found to be highly enriched with13C. The yield and13C-atom fraction of CBr2F2 were examined as functions of pulse number, laser line, laser fluence, total pressure, and Br2 pressure using a CO2 TEA laser with an output less than 1 J pulse−1 in order to optimize experimental conditions for13C separation. For example, we obtained CBr2F2 at a13C concentration of 55% in the irradiation of the mixture of 100-Torr CHClF2 and 10-Torr Br2 with the laser radiation at a wavenumber of 1045.02 cm−1 and at a fluence of 3.4 J cm−2. The mechanism for the IRMPD is discussed on the basis of observed results. Using 8-J pulses, we were able to obtain 1.9×10−4 g of13C-enriched CBr2F2 (13C-atom fraction, 47%) per pulse under selected conditions. It is possible to produce 90% or higher13C by the second-stage IRMPD of the CBr2F2 in the presence of oxygen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...