Abstract The synthesis of Coppinger's radical (galvinoxyl) with perdeuteriated tert-butyl groups is described. Its EPR spectrum exhibits markedly decreased line widths (0.015 mT) compared with the unlabelled radical (0.039 mT). The correspondingly higher resolution allows a complete analysis of the 13 C hyperfine coupling constants. A comparison of the EPR and ENDOR spectra of unlabelled and of two selectively deuteriated Coppinger's ...
