EPR and ENDOR Studies of 6-Substituted Benzopyrene Cation Radicals

Article abstract of DOI:10.1021/ja00262a012

The EPR spectrum of 6-methylbenzopyrene (6-CH3-BaP) in thallium(III)tris(trifluoroacetate)-trifluoroacetic acid (TTFA/TFA) solutions has been analyzed in terms of the 6-CH3-BaP cation radical with the aid of the ENDOR spectrum.Benzopyren (BaP) in TTFA/TFA gives an EPR and ENDOR spectra which are assigned and analyzed as the 6-(trifluoroacetoxy)benzopyrene cation radical.The EPR of several other 6-substituted BaP's have been investigated in both H2SO4 and TTFA/TFA solutions.Reactions of 6-CH3-BaP and 6-F-BaP in H2SO4 were observed.The EPR spectrum of 6-CH3-BaP(+.) changes over a period of an hour into the spectrum identical with that of 6-CH2OH-BaP(+.).Similarly, the EPR spectrum of 6-F-BaP(+.) in H2SO4 changes to one identical with 6-OH-BaP(+.).These observations are discussed in terms of their possible significance to the metabolic reactions of these compounds.