Synthesis and Crystal Structure of 4-Azido-2,2,6,6-Tetramethylpiperidine-1-oxyl Free Radical

The title compound 4-azido-2,2,6,6-tetramethylpiperidine-1-oxyl (C9H17N4O, Mr = 197.27) has been synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P(1-) with a = 5.8464(12), b = 8.2476(17), c = 11.954(2)(A), α = 101.973(4), β = 97.186(3), γ = 100.232(3)°, V = 546.98(19)(A)3, Z = 2, Dc = 1.198 g/cm3, μ(MoKα) = 0.082 mm-1, F(000) = 214, R = 0.0495 and wR = 0.1355 for 1677 observed reflections with I > 2σ(I). X-ray analysis reveals that the six-membered ring adopts a chair conformation and the bond length of N(1)-O(1) is 1.2838(19)(A).