Experimental Crystal data

R factor = 0.048; wR factor = 0.130; data-to-parameter ratio = 16.4. In the title compound, C24H19N3O, the pyrazole ring is close to being planar (r.m.s. deviation of the five fitted atoms = 0.062 Å), and each of the N-bound quinoline ring [dihedral angle = 9.90 (7)] and the C-bound phenyl ring in the 3-position is close to being coplanar [dihedral angle = 8.87 (9)]. However, the phenyl ring in the 5-position forms a dihedral angle of 72.31 (9). The hydroxy group forms an intra-molecular hydrogen bond to the quinoline N atom. In the crystal, molecules are connected into supramolecular layers two molecules thick in the bc plane by C—H O and C— H interactions. Related literature For applications of coordination complexes of hydrazones as organic light emitting diodes and supramolecular magnetic clusters, see: Zhang et al. (2011, 2012). For the synthesis of hydrazones, see: Gupta et al. (2007). For background to and the synthesis of the target molecules, see: Najib et al