The Structure of N1‐Hydroxylophine N3‐Oxide (=1‐Hydroxy‐2,4,5‐ triphenyl‐1H‐imidazole 3‐Oxide) in the Solid State

Abstract

AbstractThe crystal structure of 1‐hydroxy‐2,4,5‐triphenyl‐1H‐imidazole 3‐oxide (1) has been determined from laboratory X‐ray powder‐diffraction data. The two independent molecules in the asymmetric unit form chains via OH⋅⋅⋅O hydrogen bonds related by a twofold screw axis. One of the O⋅⋅⋅O distances is extremely short (2.32(1) and 2.43(1) Å). Solid‐state NMR spectroscopy (CPMAS) combined with calculation of absolute shieldings (GIAO/B3LYP/6‐31G*) allowed us to determine that the compound behaves as if the OH⋅⋅⋅O hydrogen bond has the proton in the middle (single‐well potential), resulting in the near identity of both 15N‐NMR signals.