2-{[5-(Pyridin-4-yl)-4-p-tolyl-4H-1,2,4-triazol-3-yl]meth­yl}acrylic acid hemi­hydrate

The asymmetric unit of the title compound, 2C18H16N4O2·H2O, consists of two organic molecules and one solvent molecule. The symmetry-independent organic mol­ecules have slightly different conformations: the 1,2,4-triazole ring forms dihedral angles of 84.61 (4), 89.68 (5) and 22.38 (6)°, respectively, with the 2-propenecarbocylic, p-tolyl and 4-pyridyl groups in one independent molecule, and 71.35 (4), 82.13 (5) and 24.82 (6)°, respectively, in the second. In the crystal, mol­ecules ralated by the 21 screw axes are assembled via O—H⋯N and O—H⋯O hydrogen bonds into infinite chains and these are linked by further O—H⋯N hydrogen bonds into undulating sheets parallel to the bc plane. Adjacent sheets are connected by weak C—H⋯O inter­actions, forming a three-dimensional structure.