Abstract
A second monoclinic polymorph of 5,6-diphenyl-3-(2-pyridyl)1,2,4- triazine, C20H14N4, is reported. The unit-cell dimensions and the orientation of the pyridine ring with respect to the triazine ring are different from those of the previously reported monoclinic form [Eltayeb, Teoh, Ng, Fun & Ibrahim (2007). Acta Cryst. E63, o1041-o1042]. In the crystal structure, intermolecular C-H center dot center dot center dot N interactions connect the molecules into chains along the c axis. The crystal packing is also stabilized by C-H center dot center dot center dot pi and pi-pi [centroid-centroid distance 3.5917 (9) angstrom] interactions. The crystal used was twinned and the ratio of the twin components refined to 0.726 (1)/0.274 (1).