(E)-1-Methyl-4-[2-(2-naphthyl)vinyl]pyridinium iodideThis paper is dedicated to the late Her Royal Highness Princess Galyani Vadhana Krom Luang Naradhiwas Rajanagarindra for her patronage of Science in Thailand.

• Main Authors: Hoong Kun Fun, Kullapa Chanawanno, Suchada Chantrapromma
• Format: Article
• Language: English
• Published: International Union of Crystallography 2009-06-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536809019114

In the title compound, C18H16N+·I−, the cation is disordered over two orientations related by a 180° rotation about its long axis with occupancies of 0.554 (7) and 0.446 (7). Both disorder components exist in an E configuration. The dihedral angle between the pyridinium ring and the naphthalene ring system is 4.7 (6)° in the major disorder component and 1.6 (8)° in the minor component. In the crystal structure, centrosymmetrically related cations are stacked along the a axis, with significant π–π interactions between the pyridinium ring and the naphthalene ring system [centroid-centroid distance = 3.442 (9) Å]. The iodide ions are located between adjacent columns of cations. The cations are linked to the iodide ions by C—H...I interactions. Weak C—H...π interactions involving the methyl group are also observed.