1-Methyl-2-[(E)-2-(2-thien­yl)ethen­yl]quinolinium iodide

Pumsak Ruanwas; Thawanrat Kobkeatthawin; Suchada Chantrapromma; Hoong-Kun Fun; Chatchanok Karalai

doi:10.1107/S1600536808020734

. 2008 Jul 9;64(Pt 8):o1453–o1454. doi: 10.1107/S1600536808020734

1-Methyl-2-[(E)-2-(2-thienyl)ethenyl]quinolinium iodide¹

Pumsak Ruanwas ^a, Thawanrat Kobkeatthawin ^a, Suchada Chantrapromma ^a,^*, Hoong-Kun Fun ^b,^‡, Chatchanok Karalai ^a

PMCID: PMC2962084 PMID: 21203168

Abstract

In the title compound, C₁₆H₁₄NS⁺·I⁻, the cation has an E configuration about the C=C double bond of the ethylene unit. The dihedral angle between the thiophene ring and the quinolinium ring system is 11.67 (11)°. A weak C—H⋯S intramolecular interaction involving the thiophene ring generates an S(5) ring motif. In the crystal structure, the iodide ion, located between the cations arranged in an antiparallel manner, forms weak C—H⋯I interactions. The crystal structure is further stabilized by a π–π interaction between the thiophene and pyridine rings; the centroid–centroid distance is 3.6818 (13) Å.

Related literature

For bond lengths, see: Allen et al. (1987 ▶). For related literature on hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For related structures, see, for example: Chantrapromma et al. (2006 ▶, 2008 ▶); Chantrapromma, Jindawong & Fun (2007 ▶); Chantrapromma, Jindawong, Fun & Patil (2007 ▶). For background literature on non-linear optical properties, see, for example: Chou et al. (1996 ▶); Dittrich et al. (2003 ▶); Drost et al. (1995 ▶); Morley (1991 ▶).

Experimental

Crystal data

C₁₆H₁₄NS⁺·I⁻
M _r = 379.25
Triclinic,
a = 7.8243 (1) Å
b = 9.6906 (1) Å
c = 10.7633 (2) Å
α = 97.521 (1)°
β = 95.338 (1)°
γ = 112.758 (1)°
V = 736.82 (2) Å³
Z = 2
Mo Kα radiation
μ = 2.30 mm⁻¹
T = 100.0 (1) K
0.58 × 0.28 × 0.14 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.346, T _max = 0.725
17060 measured reflections
4261 independent reflections
4118 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.022
wR(F ²) = 0.059
S = 1.10
4261 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 1.50 e Å⁻³
Δρ_min = −0.90 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); 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, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808020734/is2311sup1.cif

e-64-o1453-sup1.cif^{(18.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808020734/is2311Isup2.hkl

e-64-o1453-Isup2.hkl^{(208.8KB, 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
C10—H10A⋯S1	0.93	2.80	3.189 (2)	106
C11—H11A⋯I1ⁱ	0.93	3.06	3.934 (2)	157
C16—H16B⋯I1ⁱⁱ	0.96	3.06	3.962 (2)	156

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The Center for Innovation in Chemistry: Postgraduate Education and Research Program in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of Education and the Graduate School, Prince of Songkla University are gratefully acknowledged for providing financial support to PR. The authors thank the Prince of Songkla University for a research grant and also the Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

The design and synthesis of conjugated compounds to search for second-order nonlinear optic (NLO) materials have generated extensive interest. From previous reports, both molecular orbital calculations (Morley, 1991) and experimental studies (Drost et al., 1995) have revealed that the products of dipole moment and molecular hyperpolarizability (υβ) of thiophene-containing conjugated moieties are superior to that of benzene analogues. Based on this reason we have previously studied the compound containing thiophene unit, namely, 1-methyl-4-[(E)-2-(2-thienyl)ethenyl]-pyridinium 4-chlorobenzenesulfonate (Chantrapromma et al., 2008). In this paper we have synthesized the title compound which was designed by the replacement of the cationic 3-hydroxy-4-methoxyphenyl ring that is present in a compound possessing second-harmonic-generation (SHG) properties, 2-[(E)-2-(3-hydroxy-4-methoxyphenyl)ethenyl]-1methylquinolinium, iodide monohydrate (Chantrapromma, Jindawong, Fun & Patil, 2007) by the thiophene unit. Herein we report the synthesis and crystal structure of the title compound.

The asymmetric unit of the title compound (Fig. 1) consists of the C₁₆H₁₄NS⁺ cation and I^- ion. The cation exists in the E configuration with respect to the C10═C11 double bond [1.350 (3) Å] and is almost planar with the interplanar angle between the quinolinium and the thiophene ring being 11.67 (11)° and the torsion angles C9–C10–C11–C12 = -178.56 (17)°. The ethenyl unit is co-planar with the thiophene ring as can be indicated by the torsion angles C10–C11–C12–C13 = -179.42 (18)° and C10–C11–C12–S1 = 1.4 (3)°. It is slightly deviated from the quinolinium ring with the torsion angle C8–C9–C10–C11 = -14.2 (3)°. The atom S1 of the thiophene ring contributes to the C—H···S intramolecular weak interaction (Fig. 1 and Table 1) forming S(5) ring motifs (Bernstein et al., 1995). The bond lengths and angles are normal (Allen et al., 1987) and are comparable with closely related structures (Chantrapromma et al., 2006, 2008; Chantrapromma, Jindawong & Fun, 2007; Chantrapromma, Jindawong, Fun & Patil, 2007).

In the crystal packing (Fig. 2), the I^- ion is in between each pair of the two antiparallel cations and is linked with the cations through weak C—H···I interactions. The crystal is stabilized by weak C—H···S and C—H···I interactions (Table 1). A π–π interaction was observed with the Cg₁···Cg₂ distance of 3.6818 (13) Å; Cg₁ⁱ and Cg₂ⁱ are the centroids of the S1/C12–C15 and N1/C1/C6–C9 rings, respectively [symmetry code: (i): 1 - x, 1 - y, 1 - z]. The perpendicular distances of Cg₂ onto the plane of the S1/C12–C15 ring and Cg₁ onto the plane of the N1/C1/C6–C9 ring are 3.200 and 3.500Å, respectively

Experimental

2-(2-Thiophenestyryl)-1-methylquinilinium iodide was synthesized by mixing a solution (1:1:1 molar ratio) of 1,2-dimethylquinolinium iodide (2.00 g, 7.0 mmol), 2-thiophenecarboxaldehyde (0.64 ml, 7.0 mmol) and piperidine (0.69 ml, 7.0 mmol) in hot methanol (40 ml). The resulting solution was refluxed for 5 hr under a nitrogen atmosphere. The resultant solid was filtered off and washed with diethyl ether. Brown block-shaped single crystals of the title compound suitable for x-ray structure determination were obtained after recrystalization from methanol by slow evaporation of the solvent at room temperature after a few weeks.