(E)-4-[4-(Diethyl­amino)­benzyl­idene­ammonio]­benzene­sulfonate

Pumsak Ruanwas; Suchada Chantrapromma; Hoong-Kun Fun

doi:10.1107/S1600536812026402

. 2012 Jun 20;68(Pt 7):o2155–o2156. doi: 10.1107/S1600536812026402

(E)-4-[4-(Diethylamino)benzylideneammonio]benzenesulfonate

Pumsak Ruanwas ^a, Suchada Chantrapromma ^b,^*,^‡, Hoong-Kun Fun ^c,^§

PMCID: PMC3393963 PMID: 22798828

Abstract

The title compound, C₁₇H₂₀N₂O₃S, synthesised from sulfanilic acid and 4-diethylaminobenzaldehyde, crystallized out as a zwitterion with the central N atom protonated. The zwitterion exists in an E conformation with respect to the C=N double bond. The dihedral angle between the benzene rings is 37.57 (5)°. In the crystal, the zwitterions are linked into a tape along the a axis by N—H⋯O hydrogen bonds. The crystal structure is further stabilized by weak C—H⋯O interactions and π–π interactions with a centroid–centroid distance of 3.8541 (6) Å. An O⋯O [2.8498 (11) Å] short contact is present.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For related structures, see: Banu & Golzar Hossain (2006 ▶); Yeap et al. (2010 ▶). For background and applications to sulfanilic acids, see: Chanawanno et al. (2010 ▶); Hussain et al. (2009 ▶); Kim et al. (2011 ▶); King (1991 ▶); Taylor et al. (2006 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₇H₂₀N₂O₃S
M _r = 332.42
Triclinic,
a = 8.1227 (1) Å
b = 8.8745 (1) Å
c = 12.4070 (2) Å
α = 69.386 (1)°
β = 72.442 (1)°
γ = 75.509 (1)°
V = 787.63 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 100 K
0.45 × 0.22 × 0.14 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.906, T _max = 0.969
24759 measured reflections
5685 independent reflections
5040 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.097
S = 1.04
5685 reflections
214 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.77 e Å⁻³
Δρ_min = −0.40 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 datablock(s) global, I. DOI: 10.1107/S1600536812026402/is5152sup1.cif

e-68-o2155-sup1.cif^{(26.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812026402/is5152Isup2.hkl

e-68-o2155-Isup2.hkl^{(278.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812026402/is5152Isup3.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
N1—H1N1⋯O3ⁱ	0.865 (18)	2.466 (17)	3.0309 (12)	123.6 (13)
N1—H1N1⋯O3ⁱⁱ	0.865 (18)	2.076 (18)	2.8989 (12)	158.7 (16)
C7—H7A⋯O2ⁱⁱⁱ	0.93	2.39	3.2719 (13)	157
C13—H13A⋯O3ⁱⁱ	0.93	2.40	3.3002 (13)	164
C14—H14A⋯O1^iv	0.97	2.58	3.4805 (14)	155

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

Acknowledgments

PR thanks the Thailand Research Fund through the Royal Golden Jubilee PhD Program (grant No. PHD/0314/2552) and the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Office of the Higher Education, Ministry of Education, Thailand, for financial support. The authors also thank Prince of Songkla University and Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

Benzenesulfonic acid is a very strong acid and coupled with aromatic components are interesting chemical reagents (King, 1991). Many of these combinations exhibit pharmaceutical and biological activities (Chanawanno et al., 2010; Taylor et al., 2006) and were also used as whitening reagents (Hussain et al., 2009) and fluorescence sensors (Kim et al., 2011). The title compound (I) was synthesized on account of its fluorescence property. It was found that (I) shows solid state fluorescence with the maximum emission at 625 nm when was excited at 400 nm. Herein the synthesis and crystal structure of (I) are reported.

In Fig. 1, the molecule of (I), C₁₇H₂₀N₂O₃S, crystallized out as a zwitterion with the N1 atom protonated. The hydrogen is more preferably attached to the nitrogen atom due to the stronger basicity of NH₂ group compared to the SO₃^- substituent (Banu & Golzar Hossain, 2006; Yeap et al., 2010). The zwitterion exists in an E configuration with respect to the central C═N double bond [1.3146 (12)°] with the torsion angle C6–N1–C7–C8 being 172.99 (9)°. The molecule is twisted with the dihedral angle between the two benzene rings being 37.57 (5) °. The two ethyl groups of diethylamino are out of its bound benzene ring plane with the torsion angles of C11–N2–C14–C15 = 84.88 (12)° and C11–N2–C16–C17 = 86.61 (12)° and they are oriented in oppositional directions to each other (Fig. 1). The bond distances agree with the literature values (Allen et al., 1987) and are comparable with the related structure (Yeap et al., 2010).

In the crystal packing (Fig. 2), the zwitterions are linked by intermolecular N—H···O hydrogen bonds (Table 1) into tapes along the a axis. The crystal is stabilized by intermolecular N—H···O hydrogen bonds and weak C—H···O interactions (Table 1). A π–π interaction with the distance of Cg₁···Cg₁ⁱⁱ = 3.8541 (6) Å was observed; Cg₁ is the centroid of C1–C6 benzene ring. An O···O^v short contact [2.8498 (11) Å; symmetry code (v) = -1 - x, 1 - y, 1 - z] was presented.

Experimental

Sulfanilic acid (0.5 g, 2.8 mmol) was dissolved in water (10 ml) and then 4-diethylaminobenzaldehyde (0.5 g, 2.8 mmol) was added. The mixture was refluxed at 120 °C for 2 h. The precipitate was filtered, washed with water and purified by recrystallization from ethanol to afford the compound I (yield 79%). Yellow block-shaped single crystals of the title compound suitable for X-ray structure determination were formed from recrystallization from ethanol by the slow evaporation of the solvent at room temperature after a week (m.p. 540–541 K).