N-p-nitrobenzoylpyrrolidinyl(4,5-dihydro-4,4,5,5-tetramethyl-3-oxido- 1H-imidazol-3-ium-1-oxyl-2-yl)
n-p-nitrobenzoylpyrrolidinyl(4,5-dihydro-4,4,5,5-tetramethyl-3-oxido- 1h-imidazol-3-ium-1-oxyl-2-yl)