organic compounds
4-Ammonio-5-methoxy-2-methylbenzenesulfonate
aWestChem, Department of Pure & Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland
*Correspondence e-mail: a.r.kennedy@strath.ac.uk
The title compound, C8H11NO4S, crystallizes as a zwitterion, with the negatively charged benzenesulfonate group and the positively charged NH3+ group in mutually para positions. All the non-H atoms, except for one O atom of the sulfonate group, lie on a crystallographic mirror plane (Z′ = 1/2). In the crystal, the hydrogen-bonding structure is two-dimensional, propagating in the c-axis direction through a bifurcated hydrogen bond between the NH3+ and the SO3− groups, and in the b-axis direction through an R22(16) ring motif involving the same functional groups. This latter hydrogen bonding is supported by offset π–π interactions [intercentroid distance = 3.8114 (4) Å].
Keywords: crystal structure; zwitterion; sulfonate; hydrogen bonding; offset π–π interactions.
CCDC reference: 1515425
Structure description
Amino-benzenesulfonic acids are used extensively in the preparation of azo dyes and pigments (Christie, 2015). Their crystal structures tend to be zwitterionic with a negatively charged sulfonate and protonation of the amine to give NH3+ (Smith et al., 2006; Butcher & Deschamps, 2006; Śledź et al., 2010).
The title compound, crystallizes as a zwitterion, as shown in Fig. 1. The body of the molecule lies on the crystallographic mirror plane (Z′ = ½) with only atom O3 of the sulfonate group and H atoms of the methyl and NH3+ groups out of plane. Close examination of the displacement ellipsoids of the methoxy group indicate that these are a little larger than those for the other atoms – thus there may be minor (unmodelled) out of plane disorder present.
In the crystal, hydrogen bonding involves the NH3+ group as an H-donor and the O atoms of the SO3− group as the acceptors (Table 1). This gives a two-dimensional hydrogen-bonding network (Fig. 2), with bifurcated bonds from H atom H2N to O3ii and O3iii (see Table 1), forming sheets parallel to the ab plane, and the remaining donor and acceptor atoms forming an R22(16) ring motif that supports offset π–π stacking parallel to the b-axis direction (Table 1 and Fig. 3); intercentroid distances Cg⋯Cga,b,c = 3.8114 (4) Å, Cg is the centroid of the benzene ring C1–C6, interplanar distances = 3.4705 Å, slippages = 1.575 Å, symmetry codes: (a) −x + 1, −y, −z + 1, (b) −x + 1, y − , −z + 1, (c) −x + 1, y + , −z + 1.
Synthesis and crystallization
The crystallization of 4-azaniumyl-5-methoxy-2-methylbenzene-1-sulfonate occurred during an attempt to synthesize a salt form of rac-methylephedrine by reaction with 4-amino-5-methoxy-2-methylbenzenesulfonic acid (Kennedy et al., 2011). Synthesis was by adding 1.10 mmol of the acid to 1.00 mmol of the base, both previously partially dissolved in approximately 5 ml of deionized water. The resulting solution was stirred for 30 min at 323 K, filtered into a test tube and left to slowly evaporate. The title compound crystallized as colourless plates on the walls of the test tube.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1515425
https://doi.org/10.1107/S2414314616017788/su4094sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616017788/su4094Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314616017788/su4094Isup3.cml
Data collection: CrysAlis PRO (Agilent, 2014); cell
CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).NH4+·C8H7O4S− | F(000) = 228 |
Mr = 217.24 | Dx = 1.548 Mg m−3 |
Monoclinic, P21/m | Mo Kα radiation, λ = 0.71073 Å |
a = 8.0644 (3) Å | Cell parameters from 3052 reflections |
b = 6.9410 (2) Å | θ = 3.8–28.4° |
c = 8.6192 (3) Å | µ = 0.34 mm−1 |
β = 105.039 (4)° | T = 123 K |
V = 465.94 (3) Å3 | Plate, colourless |
Z = 2 | 0.34 × 0.19 × 0.08 mm |
Oxford Diffraction Xcalibur E diffractometer | 1101 reflections with I > 2σ(I) |
Radiation source: sealed tube | Rint = 0.017 |
ω scans | θmax = 28.9°, θmin = 3.1° |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014) | h = −10→10 |
Tmin = 0.960, Tmax = 1.000 | k = −9→8 |
4897 measured reflections | l = −11→11 |
1187 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.029 | Hydrogen site location: mixed |
wR(F2) = 0.081 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0421P)2 + 0.2128P] where P = (Fo2 + 2Fc2)/3 |
1187 reflections | (Δ/σ)max < 0.001 |
103 parameters | Δρmax = 0.34 e Å−3 |
0 restraints | Δρmin = −0.46 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.3390 (2) | 0.2500 | 0.5975 (2) | 0.0141 (3) | |
C2 | 0.2229 (2) | 0.2500 | 0.4465 (2) | 0.0153 (4) | |
H2 | 0.1029 | 0.2500 | 0.4370 | 0.018* | |
C3 | 0.2838 (2) | 0.2500 | 0.3100 (2) | 0.0145 (3) | |
C4 | 0.4604 (2) | 0.2500 | 0.3286 (2) | 0.0136 (3) | |
C5 | 0.5753 (2) | 0.2500 | 0.4784 (2) | 0.0143 (3) | |
H5 | 0.6951 | 0.2500 | 0.4868 | 0.017* | |
C6 | 0.5174 (2) | 0.2500 | 0.6183 (2) | 0.0139 (3) | |
C8 | 0.6490 (2) | 0.2500 | 0.7788 (2) | 0.0179 (4) | |
N1 | 0.5211 (2) | 0.2500 | 0.18268 (18) | 0.0160 (3) | |
O1 | 0.18687 (16) | 0.2500 | 0.15613 (15) | 0.0203 (3) | |
O2 | 0.06437 (18) | 0.2500 | 0.70299 (17) | 0.0283 (4) | |
O3 | 0.31405 (13) | 0.07835 (14) | 0.85950 (11) | 0.0242 (3) | |
S1 | 0.24756 (5) | 0.2500 | 0.76544 (5) | 0.01480 (15) | |
C7 | 0.0052 (3) | 0.2500 | 0.1290 (3) | 0.0410 (7) | |
H1N | 0.583 (2) | 0.146 (2) | 0.1771 (19) | 0.023 (4)* | |
H2N | 0.430 (4) | 0.2500 | 0.097 (3) | 0.037 (7)* | |
H8B | 0.642 (2) | 0.140 (3) | 0.844 (2) | 0.033 (5)* | |
H7B | −0.033 (3) | 0.136 (3) | 0.178 (3) | 0.053 (6)* | |
H7A | −0.036 (4) | 0.2500 | 0.022 (4) | 0.056 (9)* | |
H8A | 0.762 (4) | 0.2500 | 0.763 (3) | 0.043 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0145 (8) | 0.0160 (8) | 0.0127 (8) | 0.000 | 0.0055 (6) | 0.000 |
C2 | 0.0126 (8) | 0.0195 (9) | 0.0142 (8) | 0.000 | 0.0041 (6) | 0.000 |
C3 | 0.0145 (8) | 0.0164 (8) | 0.0116 (8) | 0.000 | 0.0017 (6) | 0.000 |
C4 | 0.0163 (8) | 0.0146 (8) | 0.0116 (8) | 0.000 | 0.0066 (6) | 0.000 |
C5 | 0.0118 (8) | 0.0163 (8) | 0.0149 (8) | 0.000 | 0.0038 (6) | 0.000 |
C6 | 0.0140 (8) | 0.0153 (8) | 0.0123 (8) | 0.000 | 0.0033 (6) | 0.000 |
C8 | 0.0142 (9) | 0.0258 (10) | 0.0127 (8) | 0.000 | 0.0018 (6) | 0.000 |
N1 | 0.0156 (8) | 0.0219 (8) | 0.0117 (7) | 0.000 | 0.0059 (6) | 0.000 |
O1 | 0.0149 (7) | 0.0344 (8) | 0.0105 (6) | 0.000 | 0.0010 (5) | 0.000 |
O2 | 0.0150 (7) | 0.0522 (10) | 0.0195 (7) | 0.000 | 0.0077 (5) | 0.000 |
O3 | 0.0332 (6) | 0.0241 (5) | 0.0201 (5) | 0.0068 (4) | 0.0156 (4) | 0.0057 (4) |
S1 | 0.0150 (2) | 0.0192 (2) | 0.0118 (2) | 0.000 | 0.00628 (16) | 0.000 |
C7 | 0.0151 (10) | 0.088 (2) | 0.0167 (10) | 0.000 | −0.0021 (8) | 0.000 |
C1—C2 | 1.392 (2) | C6—C8 | 1.510 (2) |
C1—C6 | 1.403 (2) | C8—H8B | 0.960 (18) |
C1—S1 | 1.7869 (17) | C8—H8A | 0.96 (3) |
C2—C3 | 1.388 (2) | N1—H1N | 0.886 (18) |
C2—H2 | 0.9500 | N1—H2N | 0.89 (3) |
C3—O1 | 1.354 (2) | O1—C7 | 1.422 (3) |
C3—C4 | 1.391 (2) | O2—S1 | 1.4351 (14) |
C4—C5 | 1.380 (2) | O3—S1 | 1.4625 (10) |
C4—N1 | 1.464 (2) | S1—O3i | 1.4624 (10) |
C5—C6 | 1.401 (2) | C7—H7B | 0.99 (2) |
C5—H5 | 0.9500 | C7—H7A | 0.90 (4) |
C2—C1—C6 | 122.56 (15) | C1—C6—C8 | 124.83 (15) |
C2—C1—S1 | 116.02 (13) | C6—C8—H8B | 113.8 (11) |
C6—C1—S1 | 121.42 (13) | C6—C8—H8A | 109.9 (17) |
C3—C2—C1 | 119.50 (16) | H8B—C8—H8A | 106.4 (14) |
C3—C2—H2 | 120.2 | C4—N1—H1N | 111.3 (11) |
C1—C2—H2 | 120.2 | C4—N1—H2N | 108.6 (18) |
O1—C3—C2 | 126.10 (16) | H1N—N1—H2N | 108.0 (14) |
O1—C3—C4 | 115.26 (15) | C3—O1—C7 | 118.00 (15) |
C2—C3—C4 | 118.64 (16) | O2—S1—O3i | 113.68 (5) |
C5—C4—C3 | 121.77 (15) | O2—S1—O3 | 113.68 (5) |
C5—C4—N1 | 120.73 (15) | O3i—S1—O3 | 109.11 (8) |
C3—C4—N1 | 117.49 (15) | O2—S1—C1 | 107.28 (8) |
C4—C5—C6 | 120.80 (16) | O3i—S1—C1 | 106.27 (5) |
C4—C5—H5 | 119.6 | O3—S1—C1 | 106.27 (5) |
C6—C5—H5 | 119.6 | O1—C7—H7B | 110.8 (13) |
C5—C6—C1 | 116.72 (15) | O1—C7—H7A | 105 (2) |
C5—C6—C8 | 118.44 (15) | H7B—C7—H7A | 111.6 (17) |
C6—C1—C2—C3 | 0.000 (1) | C2—C1—C6—C5 | 0.000 (1) |
S1—C1—C2—C3 | 180.000 (1) | S1—C1—C6—C5 | 180.000 (1) |
C1—C2—C3—O1 | 180.000 (1) | C2—C1—C6—C8 | 180.000 (1) |
C1—C2—C3—C4 | 0.000 (1) | S1—C1—C6—C8 | 0.000 (1) |
O1—C3—C4—C5 | 180.000 (1) | C2—C3—O1—C7 | 0.000 (1) |
C2—C3—C4—C5 | 0.000 (1) | C4—C3—O1—C7 | 180.000 (1) |
O1—C3—C4—N1 | 0.000 (1) | C2—C1—S1—O2 | 0.000 (1) |
C2—C3—C4—N1 | 180.000 (1) | C6—C1—S1—O2 | 180.000 (1) |
C3—C4—C5—C6 | 0.000 (1) | C2—C1—S1—O3i | −121.93 (5) |
N1—C4—C5—C6 | 180.000 (1) | C6—C1—S1—O3i | 58.07 (5) |
C4—C5—C6—C1 | 0.000 (1) | C2—C1—S1—O3 | 121.93 (5) |
C4—C5—C6—C8 | 180.000 (1) | C6—C1—S1—O3 | −58.07 (5) |
Symmetry code: (i) x, −y+1/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O3ii | 0.89 (2) | 1.83 (2) | 2.7100 (13) | 171.9 (16) |
N1—H2N···O3iii | 0.89 (3) | 2.35 (3) | 3.0909 (18) | 141 (1) |
N1—H2N···O3iv | 0.89 (3) | 2.35 (3) | 3.0909 (18) | 141 (1) |
Symmetry codes: (ii) −x+1, −y, −z+1; (iii) x, y, z−1; (iv) x, −y+1/2, z−1. |
Acknowledgements
The financial support of a PhD studentship by CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) and the support of GSK is gratefully acknowledged.
References
Agilent (2014). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England. Google Scholar
Butcher, R. J. & Deschamps, J. (2006). Acta Cryst. E62, o3768–o3770. Web of Science CSD CrossRef IUCr Journals Google Scholar
Christie, R. (2015). In Colour Chemistry, 2nd ed. Cambridge: Royal Society of Chemistry. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Kennedy, A. R., Morrison, C. A., Briggs, N. E. B. & Arbuckle, W. (2011). Cryst. Growth Des. 11, 1821–1834. Web of Science CSD CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Śledź, P., Kamiński, R., Chruszcz, M., Zimmerman, M. D., Minor, W. & Woźniak, K. (2010). Acta Cryst. B66, 482–492. Web of Science CSD CrossRef IUCr Journals Google Scholar
Smith, G., Wermuth, U. D., Young, D. J. & White, J. M. (2006). Acta Cryst. E62, o948–o950. Web of Science CSD CrossRef IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.