2,4,5-Tris(pyridin-4-yl)-1H-imidazole monohydrate

In the crystal structure of the title compound, C18H13N5·H2O, adjacent molecules are linked by O—H⋯N and N—H⋯O hydrogen bonds, generating a chain propagating along [001].

In the crystal structure of the title compound, C 18 H 13 N 5 ÁH 2 O, adjacent molecules are linked by O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds, generating a chain propagating along [001].
We report herein on the crystal structure of the title compound (Fig. 1). In the crystal lattice the molecules are linked by O-H···N and N-H···O hydrogen bonds (Jiang et al. 2011;Li et al. 2011;Li 2011) interactions to generate a one-dimensional double chain structure (Fig. 2).

Experimental
The 2,4,5-tri(4-pyridyl)imidazole was prepared by the methord reported in the literature (Proskurnina et al. 2002). A mixture of 2,4,5-tri(4-pyridyl)imidazole (0.030 g, 0.1 mmol), 2 drops of 1 mol/L HCl and water (10 mL) was placed in a 25 mL Teflon-lined autoclave and heated for 3 d at 433 K under autogenous pressure. Upon cooling and opening the bomb, colourless block-shaped crystals were obtained, then washed with water and dried in air.

Refinement
All H atoms on C atoms were positioned geometrically and refined as riding atoms, with (C-H = 0.93 Å) and refined as riding, with U iso (H)= 1.2 U eq (C). The hydrogen atoms of water molecules were located in a difference Fourier map, and were refined with suitable O-H distance restraint; U iso = 1.5 U eq (O). Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. All H atoms are presented as a small spheres of arbitrary radius.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 > 2sigma(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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )