Lophine (2,4,5-triphenyl-1H-imidazole).

The title compound, C(21)H(16)N(2), has been known since 1877. Although the crystal structure of 36 derivatives of lophine are known, the structure of parent compound has remained unknown until now. The three phenyl rings bonded to the imidazole core are not coplanar with the latter, with dihedral angles of 21.4 (3), 24.7 (3), and 39.0 (3)°, respectively, between the phenyl ring planes in the 2-, 4- and 5-positions of the imidazole ring. The mol-ecules are packed in layers running perpendicular to the b axis. Although there are acceptor and donor atoms for hydrogen bonds, no such inter-actions are detected in the crystal in contrast to other lophine derivatives.