Nitroxide radicals. Part XVII. Transannular interactions in [2.2]paracyclophanyl nitroxides

Abstract

N.m.r. measurements on four [2.2]paracyclophanyl t-butyl nitroxides indicate that there is substantial interaction of the unpaired electron with the proton which is pseudo-gem to the nitroxide group. Pseudo-p-[2.2]paracyclophanylene bis-(t-butyl nitroxide) couples intramolecularly O-to-pseudo-gem-C, in solution to give mainly [2.2]paracyclophanequinone t-butylimine N-oxide.