1,2-Diphenyl-1H-imidazo[4,5-f][1,10]phenanthroline

In the title compound, C25H16N4, the fused ring system is essentially planar [maximum deviation = 0.1012 (15) ]. The imidazole ring makes dihedral angles of 77.41 (8) and 56.26 (8)° with the phenyl rings attached to nitrogen and carbon, respectively. The dihedral angle between the two phenyl rings is 65.50 (8)°. Weak C—H...π interactions are found in the crystal structure.