ESTIMATION OF REDUCTION AND STANDARD POTENTIALS OF SOME ALLYL AND SUBSTITUTED ALKYL RADICALS

Anion radicals of aromatic compounds react with alkyl halides by dissociative electron transfer; the radicals thus formed may either couple with the anion radicals or may be reduced by the anion radicals. The competition between the coupling and the reduction may be used to determine the reduction potential and standard potential of the radicals. In this report the results concerning the redox properties of allyl radicals and different kinds of alkyl radical, such as methyl, ethyl and propyl, very sterically hindered alkyl radicals and 2-methoxy-substituted cycloalkyl radicals, are presented. The standard potentials of the allyl radicals are between -1.39 and -1.72 V vs. SCE. For most of the alkyl radicals the interval is from -1.63 to -1.81 V. However, the potential of the methyl radical is, quite unexpectedly, found by this method to be approximately 400 mV more positive than the potential of a primary alkyl radical and even more positive than that of the benzyl radical.