Crystal structure of 4-({5-[(E)-(3,5-difluorophenyl)-diazenyl]-2-hydroxybenzylidene}amino)-2,2,6,6-tetramethylpiperidin-1-oxyl

The asymmetric unit of the title compound, C22H25F2N4O2, contains two crystallographically independent molecules. In one molecule, the two benzene rings are oriented at a dihedral angle of 1.93 (10)degrees and in the other molecule the corresponding dihedral angle is 7.19 (9)degrees. The piperidine rings in the two molecules adopt a similar distorted chair conformation, and both have pseudomirror planes passing through the N-O bonds. An intramolecular O-H center dot center dot center dot N hydrogen bond between the hydroxy group and the imine N atom is observed in both molecules. In the crystal, weak C-H center dot center dot center dot O and C-H center dot center dot center dot F hydrogen bonds, enclosing R-2(2)(6) ring motifs, and weak pi-pi stacking interactions link the molecules into a three-dimensional supramolecular network, with centroid-to-centroid distances between the nearly parallel phenyl and benzene rings of adjacent molecules of 3.975 (2) and 3.782 (2) angstrom.