title: 2-[(E)-2-(4-Ethoxy-phen-yl)ethen-yl]-1-methyl-pyridinium iodide monohydrate.
abstract: In the title compound, C(16)H(18)NO(+)·I(-)·H(2)O, the cation is essentially planar, with a dihedral angle of 3.13 (16)° between the pyridinium and benzene rings. The mol-ecule adopts an E configuration with respect to the alkene double bond. In the crystal structure, the cations are packed in an anti--parallel manner through π-π inter-actions between adjacent pyridinium and benzene rings along the a axis, with centroid-to-centroid distances of 3.615 (2) and 3.630 (2) Å. Water mol-ecules bind the iodide ions through O-H⋯I hydrogen bonds into layers. These layers link with the cations through weak C-H⋯O and C-H⋯I inter-actions.
authors.forename: Chotika
authors.initials: C
authors.lastname: Laksana
authors.forename: Pumsak
authors.initials: P
authors.lastname: Ruanwas
authors.forename: Suchada
authors.initials: S
authors.lastname: Chantrapromma
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun