3,5-Bis(4-methoxyphenyl)-1H-1,2,4-triazole monohydrate

In the title compound, C16H15N3O2·H2O, the two benzene rings and the triazole ring lie almost in the same plane, the triazole ring forming dihedral angles of 5.07 (9) and 5.80 (8)° with the benzene rings. In the crystal, there are three relatively strong intermolecular O—H⋯N and N—H⋯O hydrogen bonds, which lead to the formation of a one-dimensional double chain running parallel to the a axis. Weak π—π interactions between the benzene rings of neighboring chains with a centroid–centroid distance of 3.893 (4) Å result in the formation of layers parallel to the ac plane.

In the title compound, C 16 H 15 N 3 O 2 ÁH 2 O, the two benzene rings and the triazole ring lie almost in the same plane, the triazole ring forming dihedral angles of 5.07 (9) and 5.80 (8) with the benzene rings. In the crystal, there are three relatively strong intermolecular O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds, which lead to the formation of a one-dimensional double chain running parallel to the a axis. Weakinteractions between the benzene rings of neighboring chains with a centroid-centroid distance of 3.893 (4) Å result in the formation of layers parallel to the ac plane.

Comment
During the past decades, compounds containing triazole subunits have been intensively studied due to their diverse biological activities, such as antibacterial, antitumor, etc. and have become a central focus in the study of agricultural and medicinal chemicals (Chai et al., 2009;Nadkarni et al., 2001;Zhan et al., 2007). In a search for more effective antibacterial compounds, we have synthesized the title compound and determined its structure.
C9-N2 (1.333 (2) Å) is a carbon-nitrogen single bond, but the bond length is markedly shorter than usual carbon-nitrogen single bonds and close to a double bond due to its conjugation with the C9-N3 double bond.
The packing of the molecules in the crystal structure is stabilized through N-H···O, O-H···O and π-π interactions.
Water molecules act both as hydrogen-acceptor and as hydrogen-donor which leads to the formation of a one dimensional double chain running parallel to the a axis ( Fig. 2, Table 1). The ring made up of C10 to C15 (with the centroid Cg1) is parallel to its symmetry related counterpart with a Cg1··· Cg1 iii distance of 3.893 (4) Å [symmetry code: (iii)-x, -y, -z].
Adjacent chains are linked via these intermolecular π-π interactions between the Cg1 rings to form a two-dimentional layer parallel to the ac plane ( Fig. 3).

Experimental
A mixture of 4-methoxyphenylmethylenemalononitrile (20 mmol), hydrazine dihydrochloride (20 mmol) and hydrazine hydrate (60 mmol) in ethylene glycol (10 ml) was heated to 403 K with stirring for 3-4 h. After cooling to room temperature, the reaction mixture was diluted with water (20 ml). The precipitate was filtered, washed with water, dried and purified by column chromatography on silica gel using CH 2 Cl 2 as the eluent to afford a white solid after evaporation of the solvent.
The white solid was dissolved in ethanol and colourless crystals of the title compound were obtained on slow evaporation of the solvent at room temperature.

Refinement
Hydrogen atoms attached to carbon were placed in geometrically idealized positions (C arene -H = 0.93 Å, C methyl -H = 0.96 Å) and refined using a riding model with isotropic displacement parameters U iso = 1.2 (1.5 for methyl groups) U eq (C).

supplementary materials sup-2
The H atoms attached to N and O atoms were located by Fourier difference synthesis and refined using a riding model with isotropic displacement parameters of U iso = 1.2 U eq (N) and U iso = 1.5 U eq (O). Fig. 1. The molecular structure, with atom labels and 30% probability displacement ellipsoids.  3,5-Bis(4-methoxyphenyl)-1H-1,2,4-triazole monohydrate