The crystal structure of 3,5,7-triphenyl-4H-1,2-diazepine (monoclinic, a = 8.132, b = 13.180, c = 24.204 Å, β = 104.15°, space group P2₁/c, Z = 4) has been determined by X-ray analysis. The 1,2-diazepine ring adopts a boat conformation with a methylene group at the prow. The phenoxide group of the picrate moiety is bonded to one of the diazepine nitrogen atoms through an hydrogen bond.