The title compound, C(13)H(9)N(5), is the first asymmetric diaryl-1,2,4,5-tetra-zine to be crystallographically characterized. We have been inter-ested in this motif for incorporation into supra-molecular assemblies based on coordination chemistry. The solid state structure shows a centrosymmetric mol-ecule, forcing a positional disorder of the terminal phenyl and pyridyl rings. The mol-ecule is completely planar, unusual for aromatic rings with N atoms in adjacent ortho positions. The stacking observed is very common in diaryl-tetra-zines and is dominated by π stacking [centroid-to-centroid distance between the tetrazine ring and the aromatic ring of an adjacent molecule is 3.6 Å, perpendicular (centroid-to-plane) distance of about 3.3 Å].