The asymmetric unit of the title compound, C16H16N+·I−·H2O, contains two 1-methyl-4-{[(1E,3E)-4-phenylbuta-1,3-dienyl]}pyridinium cations, two iodide ions and two solvent water molecules.The cation is twisted slightly, the dihedral angle between the pyridinium and the phenyl rings being 10.68 (18)° in one molecule and 18.9 (3)° in the other.The two water molecules are disordered over Varistors three positions with site-occupancy ratio of 0.
9/0.7/0.4.In the crystal packing, the cations are arranged into ribbons along the b axis with the iodide ions and water molecules located between adjacent cations.The cations are linked to the iodide ions and water molecules by weak C—H.
I and C—H.O interactions, respectively.These interactions together with O—H.I hydrogen bonds link the molecules into a two-dimensional network parallel to the bc plane.π.
π interactions leather-collar with a centroid–centroid distance of 3.669 (2) Å are also observed.