The crystal structure of the title compound, C11H10N4, comprises mol-ecules in a trans conformation for which all the atoms are located in general positions. The six-membered rings are coplanar and this arrangement might be stabilized by intra-molecular N-H⋯N hydrogen bonding. In the crystal, the mol-ecules are linked into helical chains parallel to the b axis via N-H⋯N hydrogen bonding. The mol-ecular packing shows a herringbone-like pattern along the a axis. Comparison of the X-ray powder diffraction with that calculated from single crystal data proves that a pure crystalline phase was obtained and UV-Vis measurements reveal that only the trans isomer is present.