1,4-Bis(4H-1,2,4-triazol-4-yl)benzene dihydrate

The asymmetric unit of the title compound, C10H8N6·2H2O, comprises half the organic species, the molecule being completed by inversion symmetry, and one water molecule. The dihedral angle between the 1,2,4-triazole ring and the central benzene ring is 32.2 (2)°. The water molecules form O—H⋯N hydrogen bonds with N-atom acceptors of the triazole rings. C—H⋯N hydrogen bonds are also observed, giving a three-dimensional framework.

The asymmetric unit of the title compound, C 10 H 8 N 6 Á2H 2 O, comprises half the organic species, the molecule being completed by inversion symmetry, and one water molecule. The dihedral angle between the 1,2,4-triazole ring and the central benzene ring is 32.2 (2) . The water molecules form O-HÁ Á ÁN hydrogen bonds with N-atom acceptors of the triazole rings. C-HÁ Á ÁN hydrogen bonds are also observed, giving a three-dimensional framework.

D-HÁ
A comprehensive review about 1,2,4-triazole and its derivatives also has been made by Haasnoot (Haasnoot, 2000). One of the requirements for producing such macroscopic properties is to create interactions between the molecular units and the active sites within the crystal lattices. 1,2,4-Triazole and in particular its derivatives are very interesting as bridging ligands (Aromí et al., 2011).
Herein we report the synthesis and the crystal structure of the title compound, 1,4-bis(4H-1,2,4-triazol-4-yl)benzene dihydrate, (I), which is expected to act as a tetradentate ligand to form low and multi-dimensional polymers with metal atoms.
Examination of the crystal structure with PLATON (Spek, 2009) shows the water molecules form O-H···N hydrogen bonds with the N-atom acceptors of the triazole rings, O-H···N and C1-H···N3 hydrogen bonds assemble (I) into a three dimensional supramolecular structure (Table 1, Figure 2) .
The title compound were collected and recrystallized from methanol. After several recrystallizations from methanol, the air-dried product was obtained as colorless block crystals. Anal. Calcd for C 10 H 12 N 6 O 2 : C, 48.38; H, 4.87%. Found: C, 48.85; H, 4.95%..

Refinement
The water H atoms were located in a Fourier difference map and refined subject to an O-H restraint 0.88 (1)  U iso (H) = 1.2Ueq(C). All of the non-hydrogen atoms were refined anisotropically.

Figure 1
The molecular structure of (I), showing 30% probability displacement ellipsoids and the atom-numbering schemes. The superscript (I) on the atom labels corresponds to atoms generated by the symmetry operation: -x, -y, 1-z.    Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.