(E)-2-[4-(Diethyl­amino)­styr­yl]-1-ethyl­pyridinium iodide monohydrate

Suchada Chantrapromma; Nawong Boonnak; Narissara Kaewmanee; Ching Kheng Quah; Hoong-Kun Fun

doi:10.1107/S160053681300528X

. 2013 Feb 28;69(Pt 3):o458–o459. doi: 10.1107/S160053681300528X

(E)-2-[4-(Diethylamino)styryl]-1-ethylpyridinium iodide monohydrate

Suchada Chantrapromma ^a,^*,^‡, Nawong Boonnak ^b, Narissara Kaewmanee ^a, Ching Kheng Quah ^c, Hoong-Kun Fun ^d,^c,^§

PMCID: PMC3588554 PMID: 23476625

Abstract

In the title hydrated salt, C₁₉H₂₅N₂ ⁺·I⁻·H₂O, the 4-(diethylamino)phenyl unit of the cation is disordered over two positions in a 0.847 (3):0.153 (3) ratio. The cation is twisted, with dihedral angles between the pyridinium and benzene rings of 11.25 (13) and 10.7 (8)° for the major and minor components, respectively. In the crystal, the three components are linked into a centrosymmetric 2:2:2 unit by O—H⋯I and C—H⋯O hydrogen bonds. π–π interactions with centroid–centroid distances of 3.5065 (7)–3.790 (9) Å are also present.

Related literature

For background to and applications of aminostyrylpyridinium compounds, see: Chanawanno et al. (2010 ▶); Larnbert et al. (1996 ▶). For related structures, see: Fun et al. (2011a ▶,b ▶); Kaewmanee et al. (2010 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₉H₂₅N₂ ⁺·I⁻·H₂O
M _r = 426.33
Triclinic,
a = 7.9969 (1) Å
b = 9.1336 (1) Å
c = 14.7740 (2) Å
α = 96.220 (1)°
β = 105.430 (1)°
γ = 105.060 (1)°
V = 986.05 (2) Å³
Z = 2
Mo Kα radiation
μ = 1.63 mm⁻¹
T = 100 K
0.26 × 0.23 × 0.13 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.677, T _max = 0.816
32289 measured reflections
8664 independent reflections
7821 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.055
S = 1.08
8664 reflections
254 parameters
20 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.78 e Å⁻³
Δρ_min = −0.99 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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

Click here for additional data file.^{(34.2KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681300528X/is5238sup1.cif

e-69-0o458-sup1.cif^{(34.2KB, cif)}

Click here for additional data file.^{(423.8KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681300528X/is5238Isup2.hkl

e-69-0o458-Isup2.hkl^{(423.8KB, hkl)}

Click here for additional data file.^{(6.9KB, cml)}

Supplementary material file. DOI: 10.1107/S160053681300528X/is5238Isup3.cml

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
O1W—H1W⋯I1ⁱ	0.85 (3)	2.71 (2)	3.5498 (12)	176 (2)
O1W—H2W⋯I1ⁱⁱ	0.86 (3)	2.75 (3)	3.6055 (13)	171 (2)
C3—H3A⋯O1W ⁱⁱⁱ	0.95	2.35	3.2072 (19)	150

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

Acknowledgments

SC, NB and NK thank Prince of Songkla University for a research grant. The authors also thank the Malaysian Government and Universiti Sains Malaysia for APEX DE2012 grant No. 1002/PFIZIK/910323.

supplementary crystallographic information

Comment

Aminostyryl pyridinium (ASP) salts have been widely synthesized and used as fluorescence dyes for lymphocytes labeling and preliminary diagnostic imaging studies on dogs having a sodium-urate-induced inflammation in their stifle joints (Larnbert et al., 1996). Moreover, ASP salts have been reported to possess antibacterial activity (Chanawanno et al., 2010). During the course of our research on synthesis and antibacterial activity of quaternary ammonium compounds (Chanawanno et al., 2010; Kaewmanee et al., 2010), the title aminostyryl pyridinium derivative (I) was synthesized and tested for antibacterial activity. Our antibacterial assay showed that (I) exhibit moderate activity against Pseudomonas aeruginosa. Herein its crystal structure is reported.

The asymmetric unit of the title compound (I) (Fig. 1) consists of the C₁₉H₂₅N₂⁺ cation, I^- anion and one H₂O molecule. The 4-diethylaminophenyl unit of the cation is disordered over two positions; the major component A and the minor component B (Fig. 1), with the refined site-occupancy ratio of 0.847 (3)/0.153 (3). The cation exists in the trans configuration with respect to the C6═C7 double bond [1.3548 (16) Å] and the torsion angle C5—C6—C7—C8 = -176.54 (12)°. The cation is twisted as indicated by the dihedral angle between the C1–C5/N1 pyridinium and the C8–C13 benzene rings being 11.25 (13) and 10.7 (8)° for the major and minor components, respectively. It is interesting that the two ethyl groups of diethylamino moiety of both major and minor components deviated from the attached benzene ring but in different conformations in that the two ethyl units of the major component A point towards the same direction (Fig. 2), whereas they pointed opposite to each other for the minor component B (Fig. 3). These orientations of the diethylamino group can be indicated by the torsion angles C11A—N2A—C16A—C17A = -81.12 (19)° and C11A—N2A—C18A—C19A = 81.4 (2)° for the major component A and C11B—N2B—C16B—C17B = 87.0 (11)° and C11B—N2B—C18B—C19B = 93.0 (19)° for the minor component B. The other ethyl unit attached to atom N1 also deviated from its bound pyridinium ring with the torsion angle C5—N1—C14—C15 = -86.95 (14)° for the major component A and -81 (7)° for the minor component B. The bond lengths of cation are in normal ranges (Allen et al., 1987) and comparable with related structures (Fun et al., 2011a,b; Kaewmanee et al., 2010).

In the crystal packing, the cations, anions and water molecules are linked into a centrosymmetric 2:2:2 unit of the three components by O—H···I hydrogen bonds and a weak C—H···O interaction (Fig. 4 and Table 1). π–π interactions with the centroid distances of Cg1···Cg1^v = 3.5065 (7) Å [symmetry code (v) = 1 - x, 2 - y, 1 - z], Cg1···Cg2ⁱⁱ = 3.5796 (16) Å and Cg1···Cg3ⁱⁱ = 3.790 (9) Å were observed; Cg1, Cg2 and Cg3 are the centroids of N1/C1–C5, C8/C9A–C13A and C8/C9B–C13B rings, respectively.

Experimental

The title compound (I) was prepared by mixing 1:1:1 molar ratio solutions of 1-ethyl-2-methylpyridinium iodide (1 g, 4 mmol), 4-diethylaminobenzaldehyde (0.7 g, 4 mmol) and piperidine (0.4 ml, 4 mmol) in methanol (40 ml). The resulting solution was stirred for 4 h under a nitrogen atmosphere. The orange solid which formed was filtered and washed with diethylether. Orange block-shaped single crystals of (I) suitable for x-ray structure determination were recrystallized from methanol by slow evaporation at room temperature over a few weeks, M.p. 446–448 K.