Hydrogen-bonding patterns in two structural isomers of 3,6-bis(2-chlorophenyl)-1,4-dihydro-1,2,4,5-tetrazine.

Two structural isomers, 3,6-bis(2-chlorophenyl)-1,4-dihydro-1,2,4,5-tetrazine, (I), and 3,5-bis(2-chlorophenyl)-4-amino-1H-1,2,4-triazole, (II), both C(14)H(10)Cl(2)N(4), form chain-like structures in the solid state, stabilized by N-H...N and N-H...Cl hydrogen bonds. A contribution from weak interactions to the strong hydrogen-bond network is observed in both structures. The secondary graph sets for intermolecular hydrogen bonds [R(2)(2)(11) for (I) and R(2)(2)(12) for (II)] indicate the similarity between the networks.