2-[(E)-2-(4-chlorophenyl)ethenyl]-1-methylpyridinium iodide monohydrate

In the title compound, C14H13ClN+center dot I-center dot H2O, the cation is nearly planar and exists in an E configuration; the dihedral angle between the pyridinium and benzene rings is 0.98 (17)degrees. The cations stack in an anti-parallel manner along the a axis through two pi-pi interactions between the pyridinium and benzene rings [centroid-centroid distances 3.569 (2) and 3.6818 (13) A, respectively]. The cation, anion and water molecule are linked into a chain along the a axis by weak C-H center dot center dot center dot O and C-H center dot center dot center dot I interactions together with O-H center dot center dot center dot I hydrogen bonds and the chains are further connected into a three-dimensional network.