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The cyclohexadienyl radical

  • E. Roduner
Part of the Lecture Notes in Chemistry book series (LNC, volume 49)

Abstract

The cyclohexadienyl radical, C6H7, was often observed by ESR of irradiated benzene [45,23]. Similarly, C6D6H was detected upon X-irradiation of benzene-d6 in adamantane [46]. The muonated analogues, C6H6Mu and C6D6Mu, were among the first organic radicals detected by μSR [8,47]. Corresponding FT-μSR spectra are shown for different magnetic fields in Figure 4.1. Only the radical lines are displayed. As in all μSR spectra of organic liquids, there is a further strong line at a low frequency corresponding to ω D for muons in diamagnetic environments. As a function of field the radical lines behave as described in Table 3.2 and on page 23. They are placed symmetrically around \( \frac{1}{2}{A_{\mu }} \) (broken line). In high fields, here 3000 G, there are two lines. The sum of the two frequencies gives the muon-electron hyperfine coupling constant directly. We obtain Aμ = 514.6 MHz for C6H6Mu and Aμ = 520.0 MHz for C6D6Mu, which corresponds to reduced coupling constants
$$ A_{\mu }^{'} = {A_{\mu }} \cdot {\mu _{p}}/{\mu _{\mu }} = 0.3142 \cdot {A_{\mu }} $$
(4.1)
of 161.7 MHz and 163.4 MHz, respectively. At 1000 G the lines of C6H6Mu split into doublets by 1.23 MHz, which is slightly less than in a less accurate early determination [26]. The splitting increases to 2.5 MHz at 700 G and 4.9 MHz at 500 G. Based on perturbation treatment (page 23) this corresponds to about 150 MHz for the coupling constant of a proton. Accurate numerical.

Keywords

Hyperfine Coupling Radical Line Hyperfine Coupling Constant Muon Polarization Pure Benzene 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • E. Roduner
    • 1
  1. 1.Physikalisch-Chemisches InstitutUniversität ZürichZürichSwitzerland

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