3,6-Bis(2-pyridyl)di-1,2,4-triazolo[3,4-a:4',3'-c]phthalazine.

The title compound, C20H12N8, (I), has been prepared by the reaction of 1,4-dihydrazinophthalazine and pyridine-2-carboxaldehyde, followed by an oxidative cyclization by treatment with bromine. In the solid state, the molecules of (I) are discrete, comprising a fused and twisted four-ring system with an overall helical appearance. The distance between the two intramolecular pyridyl N atoms is 3.075 (2) A, this short contact distance suggesting a pi-pi interaction.