α-Nitronyl Nitroxide Cation Radicals
X-Ray crystal analysis and magnetic measurements have been carried out on the first cation radical salt of α-nitronyl nitroxide, 2-(4-N-R-pyridinium)-4,4,5,5-tetrametyl-4,5-dihydro-1H-imidazol-1-oxyl 3-N-oxide iodide (with R = methyl (1) and ethyl), suggesting the separation between the spin and the charge density population, and revealing the strong antiferromagnetic intermolecular interaction of JAF/kB = 149 K in 1.