Powder EPR Spectra of Alkyl Radicals

Proton transfer from alkane radical cations to alkane molecules results in the transformation of these cations into neutral alkyl radicals (the conjugate bases). The nature of these radicals is determined by the site of proton donation in the alkane radical cation. Information on the site of proton donation in the proton transfer from alkane radical cations to alkane molecules can thus be derived from EPR spectral analysis of the neutral alkyl radicals formed. To aid the reader in appreciating the results that are presented on this matter below and in understanding related spectra from the literature, a section on the characterization of neutral alkyl radicals by EPR spectroscopy in solid systems is included at this point. 

Neutral alkyl radicals derived from n-alkanes can be separated into three distinct 

Experimental information on the powder spectra of authentic chain-end, penultimate and interior alkyl radicals can be obtained from y-irradiated solid ds-deca-lin-djg containing appropriate chloro- and bromoalkanes [18]. The EPR spectrum obtained after y-irradiation of neat ris-decalin-djg consists of a broad unresolved band, which extends over a relatively restricted spectral region as a result of spectral contraction due to deuteration (see Fig. 5.4(a)). The addition of chloro- and bromoalkanes before irradiation results in a considerable distortion of this unre- 

Symmetric Proton Transfer from Alkane Radical Cations to Alkanes An Experimental Study in y-Irradiated n-Alkane Nanoparticles Embedded in a Cryogenic CCI3F Matrix 

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