TETRAALKYL-PARA-URAZINES AND THEIR CATION RADICALS

X-ray structures for tetramethyl-p-urazine 1 and its dithia derivative 3 show these compounds to exist in significantly twisted boat structures with nearly planar nitrogens. The X-ray structure of the fused bicyloco-[2.2.2]octyl derivative cation radical 4.+ is consistent with a delocalized structure having equivalent N-N bonds and planar nitrogens. ESR and ENDOR data are consistent with delocalized cation radicals in solution. Cyclic voltammetry and cation radical optical absorption data are reported. Differences between the solvent dependence of the optical absorption maximum for 4.+ and for a bisalkoxyurea which is known to have the positive charge localized (5.+) are discussed.