(E)-1-Methyl-4-[2-(2-naphth­yl)vin­yl]pyridinium iodide

Hoong-Kun Fun; Kullapa Chanawanno; Suchada Chantrapromma

doi:10.1107/S1600536809019114

. 2009 May 29;65(Pt 6):o1406–o1407. doi: 10.1107/S1600536809019114

(E)-1-Methyl-4-[2-(2-naphthyl)vinyl]pyridinium iodide¹

Hoong-Kun Fun ^a,^*,^‡, Kullapa Chanawanno ^b, Suchada Chantrapromma ^b,^§

PMCID: PMC2969718 PMID: 21583250

Abstract

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.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For background to non-linear optical materials research, see: Cheng et al. (1991a ▶,b ▶); Ogawa et al. (2008 ▶); Yang et al. (2007 ▶). For related structures, see: Chanawanno et al. (2008 ▶); Chantrapromma et al. (2006 ▶; 2007 ▶; 2008 ▶; 2009a ▶,b ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₈H₁₆N⁺·I⁻
M _r = 373.29
Monoclinic,
a = 7.2789 (1) Å
b = 10.9363 (2) Å
c = 20.0883 (4) Å
β = 101.280 (1)°
V = 1568.22 (5) Å³
Z = 4
Mo Kα radiation
μ = 2.03 mm⁻¹
T = 100 K
0.53 × 0.30 × 0.09 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.412, T _max = 0.838
34203 measured reflections
6896 independent reflections
5373 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.148
S = 1.06
6896 reflections
338 parameters
91 restraints
H-atom parameters constrained
Δρ_max = 3.51 e Å⁻³
Δρ_min = −2.42 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809019114/ci2807sup1.cif

e-65-o1406-sup1.cif^{(26.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809019114/ci2807Isup2.hkl

e-65-o1406-Isup2.hkl^{(337.5KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C18A—H18A⋯I1ⁱ	0.96	3.05	3.928 (17)	152
C18A—H18B⋯Cg1ⁱ	0.96	2.63	3.513 (18)	153
C18A—H18B⋯Cg2ⁱ	0.96	2.65	3.517 (18)	150
C18B—H18E⋯Cg1ⁱ	0.96	2.62	3.44 (2)	143
C18B—H18E⋯Cg2ⁱ	0.96	2.66	3.45 (2)	139

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Symmetry code: (i) Inline graphic . Cg1 and Cg2 are centroids of the C10A–C15A and C10B–C15B rings, respectively.

Acknowledgments

The authors thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. KC thanks the Development and Promotion of Science and Technology Talents Project (DPST) for financial support. SC thanks Prince of Songkla University for financial support through the Crystal Materials Research Unit.

supplementary crystallographic information

Comment

In order to obtain second-order non-linear optical (NLO) single crystals, the main requirements should be the choice of molecules with large hyperpolarizability (β) and these molecules should align into a noncentrosymmetric space group in the crystal. Organic crystals with extensive conjugated π systems with large hyperpolarizability which exhibit NLO properties have been reported (Ogawa et al., 2008; Yang et al., 2007). Styryl pyridinium derivatives are considered to be good conjugated π-systems (Cheng et al., 1991a, 1991b). In our on-going research in searching for NLO materials (Chanawanno et al., 2008; Chantrapromma et al., 2006, 2007, 2008, 2009a, b), we have previously reported the crystal structure of (E)-1-methyl-4-[2-(1-naphthyl)vinyl]pyridinium 4-bromobenzenesulfonate (Chantrapromma et al., 2009a). In order to study the effect of different positions of the subsituent group and anions, the title compound was synthesized by replacing the 1-naphthyl and 4-bromobenzenesulfonate in the (E)-1-methyl-4-[2-(1-naphthyl)vinyl]pyridinium 4-bromobenzenesulfonate with 2-naphthyl and iodide in the title compound. However it crystallized in the monoclinic centrosymmetric space group P2₁/c and would not exhibit second-order nonlinear optical properties.

Fig. 1 shows the asymmetric unit of the title compound which consists of a C₁₈H₁₆N⁺ cation and a I^- anion. The whole cation is disordered over two sites; the major component A and the minor component B (Fig. 1), with the refined site-occupancy ratio of 0.554 (7)/0.446 (7). The cation exists in the E configuration with respect to the C6═C7 double bond. The napthalenyl moiety is essentially planar in both disorder components as indicated by the interplanar angle between the two aromatic C8-C10/C15-C17 and C10–C15 rings [1.5 (8)° for the major component A and 3.2 (9)° for the minor component B]. The major component A of cation is slightly twisted with the dihedral angle between the pyridinium and the mean plane through the napthalenyl moiety (C8–C17) being 4.7 (6)° whereas the minor component B is almost planar [dihedral angle 1.6 (8)°]. The C4–C5–C6–C7 and C6–C7–C8–C17 torsion angles [0.4 (10)° and 2.1 (10)° in the major component and -179.4 (8)° and 179.9 (8)° in the minor component] in both disorder components indicate that the orientations of the ethynyl moiety in these components are related by 180° rotation about the long axis of the molecule. The bond lengths are in normal ranges (Allen et al., 1987) and are comparable to those observed in related structures (Chanawanno et al., 2008; Chantrapromma et al., 2006, 2007, 2008, 2009a,b).

In the crystal packing (Fig. 2), centrosymmetrically related cations are stacked along the a axis, with significant π-π interactions between pyridinium ring and naphthalene ring system [centroid-centroid distance is 3.442 (9) Å]. The iodide ions are located between adjacent coloumns of cations. The cations are linked to the iodide ions by C—H···I weak interactions (Table 1). The crystal structure is further stabilized by C—H···π interactions involving the methyl group (Table 1; Cg1 and Cg2 are centroids of the C10A-C15A and C10B-C15B rings, respectively).

Experimental

The title compound was prepared by mixing 1:1:1 molar ratio solutions of 1,4-dimethylpyridinium iodide (2 g, 8.5 mmol), 2-naphthaldehyde (1.16 ml, 8.5 mmol) and piperidine (0.84 ml, 8.5 mmol) in methanol (40 ml). The resulting solution was refluxed for 3 h under a nitrogen atmosphere. The solid compound formed was filtered and washed with diethylether. Yellow plate-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. 557-558 K).