(E)-2-[4-(Diethyl­amino)­styr­yl]-1-methyl­pyridinium 4-chloro­benzene­sulfonate monohydrate

Hoong-Kun Fun; Narissara Kaewmanee; Kullapa Chanawanno; Chatchanok Karalai; Suchada Chantrapromma

doi:10.1107/S1600536811034258

. 2011 Aug 27;67(Pt 9):o2488–o2489. doi: 10.1107/S1600536811034258

(E)-2-[4-(Diethylamino)styryl]-1-methylpyridinium 4-chlorobenzenesulfonate monohydrate

Hoong-Kun Fun ^a,^*,^‡, Narissara Kaewmanee ^b, Kullapa Chanawanno ^b, Chatchanok Karalai ^b, Suchada Chantrapromma ^b,^§

PMCID: PMC3200709 PMID: 22059040

Abstract

In the title hydrated molecular salt, C₁₈H₂₃N₂ ⁺·C₆H₄ClO₃S⁻·H₂O, which shows moderate biological activity against methicillin-resistant Staphylococcus aureus (MRSA), one ethyl group of the 2-[4-(diethylamino)styryl]-1-methylpyridinium cation is disordered over two orientations in a 0.604 (13):0.396 (13) ratio. The main part of the cation is nearly planar with a dihedral angle of 4.50 (10)° between the pyridinium and benzene rings. In the crystal, the components are linked by O—H⋯O hydrogen bonds and C—H⋯O weak interactions. Aromatic π–π stacking interactions with centroid–centroid separations of 3.7363 (12) and 3.7490 (13) Å also occur.

Related literature

For background to and the application of quarternary ammonium compounds as disinfectants, see: Brown & Skurray (2001 ▶); Chanawanno, Chantrapromma, Anantapong, Kanjana-Opas & Fun (2010 ▶); Domagk (1935 ▶); Endo et al. (1987 ▶); Fun et al. (2011 ▶); Wainwright & Kristiansen (2003 ▶). For a related structure, see: Fun et al. (2011 ▶); Kaewmanee et al. (2010 ▶). For the synthesis, see: Chanawanno, Chantrapromma, Anantapong & Kanjana-Opas (2010 ▶). For reference bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₈H₂₃N₂ ⁺·C₆H₄ClO₃S⁻·H₂O
M _r = 477.00
Triclinic,
a = 7.2511 (3) Å
b = 10.2272 (4) Å
c = 16.7169 (7) Å
α = 88.441 (3)°
β = 80.057 (2)°
γ = 77.062 (2)°
V = 1190.00 (8) Å³
Z = 2
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 100 K
0.53 × 0.25 × 0.04 mm

Data collection

Bruker APEX Duo CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.866, T _max = 0.990
15554 measured reflections
4617 independent reflections
3369 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.118
S = 1.04
4617 reflections
320 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.32 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

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811034258/hb6382sup1.cif

e-67-o2488-sup1.cif^{(25.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811034258/hb6382Isup2.hkl

e-67-o2488-Isup2.hkl^{(226.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811034258/hb6382Isup3.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—H2W1⋯O1	0.81 (3)	1.98 (3)	2.783 (3)	174 (3)
O1W—H1W1⋯O2ⁱ	0.87 (3)	2.13 (4)	2.977 (3)	166 (3)
C2—H2A⋯O2ⁱⁱ	0.93	2.52	3.374 (3)	153
C4—H4A⋯O1Wⁱⁱⁱ	0.93	2.43	3.316 (3)	158
C13—H13A⋯O3	0.93	2.59	3.495 (3)	164
C18—H18A⋯O2^iv	0.96	2.49	3.426 (3)	166
C18—H18C⋯O3	0.96	2.57	3.202 (3)	123

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

Acknowledgments

Financial support by Prince of Songkla University is gratefully acknowledged. KC thanks the Crystal Materials Research Unit (CMRU), Prince of Songkla University for the research assistance fellowship. The authors also thank Universiti Sains Malaysia for the Research University grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

As disinfectants, quaternary ammonium compounds (QACs) have been used for hygienic care in both medical and domestic purposes due to their low toxicity and wide-ranging antimicrobial properties for a long time (Domagk, 1935). However, the long-term use of any disinfectants will lead to the resistance phenomena of some bacterial strains that makes these disinfectants to become unpractical for real life usage. The appearance of resistant microganisms against QACs, especially Methicillin-resistant Staphylococcus aureus (MRSA), made the common QACs such as benzalkonium chloride and cetylpridinium chloride to be inadequate for MRSA treatment (Wainwright & Kristiansen, 2003; Brown & Skurray, 2001). Therefore, we decided to develop the novel pyridinium QACs which were expected to overcome this Staphylococcus-resistant phenomenon by modifying the QACs structures and to study their anti-MRSA activity. Among various chromophores employed in the research for chemotherapeutic drug design, tertiary amine seems to be an interesting group to be introduced into the structure (Endo et al., 1987). The title compound (I) was one among many pyridinium QACs synthesized in our laboratory (Chanawanno, Chantrapromma, Anantapong, Kanjana-Opas & Fun, 2010) hoping for a new antibacterial drug candidate and this compound showed moderate activity against MRSA with the MIC value of 150 mg/ml. Herein its crystal structure is reported.

The asymmetric unit of the title compound (I) (Fig. 1) consists of the C₁₈H₂₃N₂⁺ cation, C₆H₄ClO₃S^- anion and one H₂O molecule. The cation exists in the E configuration with respect to the C6═C7 double bond [1.337 (3) Å]. The cation is nearly planar with the the dihedral angle between the C1–C5/N1 pyridinium and the C8–C13 benzene rings being 4.50 (10)° and the torsion angle C5–C6–C7–C8 = 177.3 (2)°. One ethyl unit of the diethylamino moiety is disordered over two orientations; the major component A and the minor component B (Fig. 1), with the refined site-occupancy ratio of 0.604 (13)/0.396 (13). The diethylamino moiety is deviated from the attached benzene ring. Its conformation can be indicated by the torsion angles C11–N2–C14–C15 = 78.6 (3)°, C11–N2–C16–C17 = -95.0 (4)° for the major component A and 107.1 (5)° for the minor component B. The cation and anion are inclined to each other as indicated by the dihedral angles between the pyridinium and benzene rings of cation, and the sulfonate substituted benzene ring being 83.96 (10) and 86.97 (11)°, respectively. The bond lengths are in normal ranges (Allen et al., 1987) and comparable with a related structures (Fun et al., 2011; Kaewmanee et al., 2010).

In the crystal packing, the cations, anions and water molecules are linked into a network by O—H..O hydrogen bonds and C—H···O weak interactions (Fig. 2 and Table 1). π···π interactions with the centroid distances of Cg₁···Cg₁ⁱⁱ = 3.7363 (12) Å and Cg₁···Cg₂^iv = 3.7490 (13) Å were observed; Cg₁ and Cg₂ are the centroids of N1/C1–C5 and C8–C13 rings, respectively.

Experimental

(E)-2-(4-(diethylamino)styryl)-1-methylpyridinium iodide (compound A, 0.13 g, 0.33 mmol) was prepared by the previous method (Kaewmanee et al., 2010) and then was mixed with silver (I) 4-chlorobenzenesulfonate (Chanawanno, Chantrapromma, Anantapong & Kanjana-Opas, 2010) (0.10 g, 0.33 mmol) in methanol (100 ml). The mixture immediately yielded a grey precipitate of silver iodide. After stirring the mixture for 30 min, the precipitate of silver iodide was removed and the resulting solution was evaporated yielding an orange solid of the title compound. Orange plates of (I) were recrystallized from methanol by slow evaporation of the solvent at room temperature after a few weeks, Mp. 446-448 K.