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

Abstract

In the title compound, C16H18NO+·I−·H2O, the cation is essentially planar, with a dihedral angle of 3.13 (16)° between the pyridinium and benzene rings. The mol­ecule 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 inter­actions 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 mol­ecules 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 inter­actions.

2-[(E)-2-(4-Ethoxyphenyl)ethenyl]-1-methylpyridinium 4-bromobenzenesulfonate monohydrate

“…The pyridinium and benzene rings of the cation form dihedral angles of 79.2 (2) and 71.0 (2)°, respectively, with the benzene ring of the anion. Bond distances in both cation and anion have normal values (Allen et al, 1987) and are comparable to those observed in related structures (Chanawanno et al, 2009;Chantrapromma et al, 2009;Laksana et al, 2008).…”

“…The orientation of ionic chromophores can be arranged simply by changing the counter-ions (Pan et al, 1996). During the course of our NLO materials research, we have previously synthesized and reported crystal structures of related pyridinium salts containing the 2-[(E)-2-(4-ethoxyphenyl)ethenyl]-1-methylpyridinium cationic part (Chanawanno et al, 2009;Laksana et al, 2008). The title compound was synthesized by retaining the same cationic part but changing the anion counter part to 4-bromobenzenesulfonate in order to investigate the influence of the counter-ions on the NLO properties.…”

“…For background to NLO materials research, see: Coe et al (2002); Pan et al (1996). For related structures, see: Chanawanno et al (2009); Chantrapromma et al (2006; Laksana et al (2008). For bond-length data, see: Allen et al (1987).…”

“…2-[(E)-2-(4-Ethoxyphenyl)ethenyl]-1-methylpyridinium iodide (0.21 g, 0.58 mmol) which was prepared according to the previous method (Laksana et al, 2008) was mixed with silver 4-bromobenzenesulfonate (Chantrapromma et al, 2006) (0.20 g, 0.58 mmol) in methanol (100 ml) and stirred for 0.5 h. The precipitate of silver iodide which formed was filtered and the filtrate was evaporated to give the title compound as a yellow solid. Yellow block-shaped single crystals of the title compound suitable for X-ray structure determination were recrystallized from methanol by slow evaporation at room temperature over a few weeks (m.p.…”

2-[(E)-2-(4-Ethoxyphenyl)ethenyl]-1-methylquinolinium iodide dihydrate

“…The ethoxy unit is coplanar with the attached benzene ring with a C15-O1-C18-C19 torsion angle of 179.9 (6)°. Bond distances in the cation have normal values (Allen et al, 1987) and are comparable to those observed in a related structure (Laksana et al, 2008).…”