4-{2-[4-(Dimethyl­amino)­phen­yl]ethen­yl}-1-methyl­pyridinium 4-nitro­benzene­sulfonate

Liang Li; Yiqiang Dai; Yun Jin; Huai Yang; Zhou Yang

doi:10.1107/S1600536812009300

. 2012 Mar 10;68(Pt 4):o994. doi: 10.1107/S1600536812009300

4-{2-[4-(Dimethylamino)phenyl]ethenyl}-1-methylpyridinium 4-nitrobenzenesulfonate

Liang Li ^a, Yiqiang Dai ^a, Yun Jin ^a, Huai Yang ^a, Zhou Yang ^a,^*

PMCID: PMC3343963 PMID: 22590044

Abstract

The asymmetric unit of the title salt, C₁₆H₁₉N₂ ⁺. C₆H₄NO₅S⁻, consists of two cations and two anions. The crystal structure is stabilized by π–π interactions between the pyridyl and phenyl rings of the cations, with a centroid–centroid distance of 3.7323 (6) Å.

Related literature

The title compound was synthesized as part of our continuing research on the non-linear optical properties of DAS (4-N,N-dimethylamino-4′-N′-methylstilbazolium) derivatives. For the synthesis, see: Okada et al. (1990 ▶). For background to non-linear optical materials, see: Yang et al. (2005 ▶); Kumar et al. (2009 ▶); Kwon et al. (2010 ▶). For the effects of different substituents of benzene sulfonate on its non-linear optical properties, see: Ogawa et al. (2008 ▶); Okada et al. (2003 ▶); Yang et al. (2007 ▶); Yin et al. (2012 ▶); Li et al. (2012 ▶). For standard bond-lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₆H₁₉N₂ ⁺·C₆H₄NO₅S⁻
M _r = 441.49
Monoclinic,
a = 18.901 (3) Å
b = 6.4504 (10) Å
c = 34.222 (6) Å
β = 96.77 (3)°
V = 4143.1 (12) Å³
Z = 8
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 173 K
0.20 × 0.16 × 0.13 mm

Data collection

Rigaku Saturn 724+ diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008 ▶) T _min = 0.752, T _max = 1.000
20075 measured reflections
9459 independent reflections
7630 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.075
wR(F ²) = 0.176
S = 1.15
9459 reflections
593 parameters
69 restraints
H-atom parameters constrained
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: CrystalClear (Rigaku, 2008 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S1600536812009300/ez2278sup1.cif

e-68-0o994-sup1.cif^{(34.4KB, cif)}

Supplementary material file. DOI: 10.1107/S1600536812009300/ez2278Isup2.cdx

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812009300/ez2278Isup3.hkl

e-68-0o994-Isup3.hkl^{(462.6KB, hkl)}

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

Acknowledgments

The authors thank the Natural Science Foundation (grant No. 50803005), the Fundamental Research Funds for the Central Universities, the Scientific Research Foundation for Returned Overseas Chinese Scholars and the National Natural Science Fund for Distinguished Young Scholars (grant No. 51025313).

supplementary crystallographic information

Comment

Nonlinear optical materials have recently invoked a large amount of interest due to their potential application in harmonic generation, optical information processing, optical storage and two photon pumped lasers (Yang et al., 2005; Kumar et al., 2009; Kwon et al., 2010). The synthesis and crystal growth of the title compound is part of our series of studies on the nonlinear optical properties of DAS (4-N, N-dimethylamino-4'-N'-methyl-stilbazolium) derivatives (Yang, Mutter et al., 2007; Yin et al., 2012; Li et al., 2012). By changing the anion from 3-nitrobenzenesulfonate to 4-nitrobenzenesulfonate, the space group has changed from monoclinic P2₁ (Ogawa et al., 2008; Okada et al., 2003) to the centrosymmetric space group monoclinic P2₁/c. Fig. 1 illustrates the molecular structure of the title salt together with the atomic numbering scheme. The asymmetric unit of the title salt consists of two 4-{2-[4-dimethylamino)phenyl]ethenyl}-1- methylpyridinium cations and two 4-nitrobenzenesulfonate anions. The bond distances and angles in both the cation and anion are in normal ranges (Allen et al., 1987).

The crystal structure is stabilized by a π-π interaction between the pyridyl and C3—C8 phenyl rings with a centroid-centroid distance of 3.7323 (6) Å. The packing diagram of the title salt obtained from X-ray analysis is presented in Fig. 2. Disorder was observed in one of the anions, whereas the structures of the cations were determined unequivocally. The crystallographic data suggests that coulombic interactions between cations and anions play a key role in crystal packing and orientation of the chromophores.

Experimental

4-{2-[4-(Dimethylamino)phenyl]ethenyl}-1-methylpyridinium 4-nitrobenzenesulfonate was prepared by the metathesization of 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium iodide (Okada et al., 1990) with the sodium salt of the 4-nitrobenzenesulfonic acid. The title salt was then recrystallized from methanol to get high purity material for crystal growth. 4-{2-[4-(Dimethylamino)phenyl]ethenyl}-1-methylpyridinium 4-nitrobenzenesulfonate: yield 79%; ¹H-NMR (300 MHz, DMSO-d₆): 8.69 (d, 2H, J= 6.6 Hz, C₅H₄N), 8.21 (d, 2H, J= 9.0 Hz, C₆H₄SO₃^-), 8.04 (d, 2H, J= 6.3 Hz, C₅H₄N), 7.93 (d, 1H, J= 16.2 Hz, CH), 7.84 (d, 2H, J= 9.0 Hz, C₆H₄SO₃^-),7.60 (d, 2H, J= 8.7 Hz, C₆H₄SO₃^-), 7.19 (d, 1H, J= 16.2 Hz, CH), 6.80(d, 2H, J= 8.7 Hz, C₆H₄), 4.17 (s, 3H, NMe), 3.02 (s, 6H, NMe₂). C, H, N analysis calcd. for C₂₂H₂₃N₃O₅S: C 59.85, H 5.25, N 9.52; found: C 59.89, H 5.32, N 9.59. Crystals were obtained by the slow cooling method from 45°C to room temperature in methanol.