title: 1,3-Diphenyl-4,5-dihydro-1H-pyrazol-5-one.
abstract: In the title pyrazolone derivative, C(15)H(12)N(2)O, the five-membered ring is approximately planar (r.m.s. deviation = 0.018 Å), and the N- and C-bound benzene rings are inclined to this plane [dihedral angles = 21.45 (10) and 6.96 (10)°, respectively] and form a dihedral angle of 20.42 (10)° with each other. Supra-molecular layers are formed in the crystal structure via C-H⋯O and C-H⋯N inter-actions, and these are assembled into double layers by C-H⋯π and π-π inter-actions between the pyrazole and C-bound benzene rings [ring centroid-centroid distance = 3.6476 (12) Å]. The double layers stack along the a axis being connected by π-π inter-actions between the N- and C-bound benzene rings [ring centroid-centroid distance = 3.7718 (12) Å].
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Baddeley
authors.forename: Solange M S V
authors.initials: SM
authors.lastname: Wardell
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell