Nitroxide radicals. Part 19. Nuclear magnetic resonance study of [2,2]paracyclophan-4-yl t-butyl nitroxide

N.m.r. measurements on specifically deuteriated [2,2]paracyclophan-4-yl t-butyl nitroxides and 4,12-[2,2]paracyclophanylene NN′-di-t-butyl bisnitroxide give clear assignments of the proton hyperfine coupling constants. There is no substantial interaction of the unpaired electron with transannular protons