3-Ammonio-4-methoxy­benzene­sulfonate

3-Amino-4-methoxy­benzene­sulfonic acid exists in the solid state in the zwitterionic form as 3-ammonio-4-methoxy­benzene­sulfonate, C₇H₉NO₄S. The zwitterions are linked by the ammonium H atoms into a layer structure.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.028
• wR factor = 0.084
• Data-to-parameter ratio = 11.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          3
PLAT731_ALERT_1_C Bond    Calc     0.86(3), Rep   0.860(10) ......       3.00 su-Rat
              N1   -H1N3    1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.86(3), Rep   0.860(10) ......       3.00 su-Rat
              N1   -H3#     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     2.10(3), Rep   2.100(10) ......       3.00 su-Rat
              H3#  -O1      1.555   2.666

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

3-Ammonio-4-methoxybenzenesulfonate

Crystal data

C7H9NO4S	Z = 2
Mr = 203.21	F(000) = 212
Triclinic, P1	Dx = 1.678 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.321 (2) Å	Cell parameters from 3869 reflections
b = 8.234 (2) Å	θ = 3.1–27.5°
c = 8.354 (2) Å	µ = 0.38 mm^−1
α = 62.05 (3)°	T = 295 K
β = 65.34 (3)°	Prism, colorless
γ = 74.04 (3)°	0.34 × 0.26 × 0.19 mm
V = 402.3 (1) Å^3

Data collection

Rigaku R-AXIS RAPID diffractometer	1830 independent reflections
Radiation source: fine-focus sealed tube	1713 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.011
ω scans	θmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −9→8
Tmin = 0.810, Tmax = 0.931	k = −10→10
3979 measured reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.084	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.053P)^2 + 0.1821P] where P = (Fo^2 + 2Fc^2)/3
1830 reflections	(Δ/σ)max = 0.001
154 parameters	Δρmax = 0.33 e Å^−3
9 restraints	Δρmin = −0.38 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.20715 (5)	0.17966 (4)	0.70736 (4)	0.0182 (1)
O1	0.3589 (2)	0.0521 (1)	0.7911 (2)	0.0259 (2)
O2	0.1115 (2)	0.0881 (1)	0.6530 (2)	0.0252 (2)
O3	0.0620 (2)	0.2766 (2)	0.8221 (2)	0.0293 (3)
O4	0.6393 (2)	0.7397 (1)	−0.0404 (1)	0.0241 (2)
N1	0.3040 (2)	0.8525 (2)	0.1882 (2)	0.0201 (2)
C1	0.3461 (2)	0.3464 (2)	0.4875 (2)	0.0185 (3)
C2	0.2715 (2)	0.5314 (2)	0.4307 (2)	0.0185 (3)
C3	0.3757 (2)	0.6567 (2)	0.2520 (2)	0.0178 (3)
C4	0.5540 (2)	0.6018 (2)	0.1294 (2)	0.0186 (3)
C5	0.6265 (2)	0.4157 (2)	0.1873 (2)	0.0218 (3)
C6	0.5224 (2)	0.2889 (2)	0.3667 (2)	0.0220 (3)
C7	0.8295 (3)	0.6943 (2)	−0.1674 (2)	0.0306 (3)
H1n1	0.313 (3)	0.904 (3)	0.069 (2)	0.042 (6)*
H1n2	0.179 (2)	0.872 (3)	0.249 (3)	0.034 (5)*
H1n3	0.370 (3)	0.910 (3)	0.206 (3)	0.033 (5)*
H2	0.152 (2)	0.574 (2)	0.510 (2)	0.029 (5)*
H5	0.744 (2)	0.373 (3)	0.106 (2)	0.033 (5)*
H6	0.575 (3)	0.163 (1)	0.404 (2)	0.027 (4)*
H71	0.936 (3)	0.651 (3)	−0.117 (3)	0.052 (6)*
H72	0.853 (3)	0.800 (2)	−0.286 (2)	0.051 (6)*
H73	0.828 (3)	0.597 (2)	−0.198 (3)	0.046 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0171 (2)	0.0166 (2)	0.0171 (2)	−0.0018 (1)	−0.0062 (1)	−0.0035 (1)
O1	0.0238 (5)	0.0233 (5)	0.0243 (5)	−0.0021 (4)	−0.0128 (4)	−0.0007 (4)
O2	0.0216 (5)	0.0266 (5)	0.0277 (5)	−0.0069 (4)	−0.0078 (4)	−0.0093 (4)
O3	0.0292 (6)	0.0277 (5)	0.0241 (5)	−0.0007 (4)	−0.0032 (4)	−0.0113 (4)
O4	0.0213 (5)	0.0215 (5)	0.0186 (5)	−0.0020 (4)	−0.0020 (4)	−0.0038 (4)
N1	0.0170 (6)	0.0163 (5)	0.0213 (6)	−0.0017 (4)	−0.0056 (5)	−0.0039 (4)
C1	0.0178 (6)	0.0174 (6)	0.0179 (6)	−0.0033 (5)	−0.0067 (5)	−0.0040 (5)
C2	0.0164 (6)	0.0194 (6)	0.0183 (6)	−0.0014 (5)	−0.0059 (5)	−0.0065 (5)
C3	0.0169 (6)	0.0151 (6)	0.0202 (6)	−0.0009 (5)	−0.0084 (5)	−0.0049 (5)
C4	0.0169 (6)	0.0204 (6)	0.0177 (6)	−0.0030 (5)	−0.0067 (5)	−0.0057 (5)
C5	0.0171 (6)	0.0227 (7)	0.0228 (7)	0.0003 (5)	−0.0047 (5)	−0.0101 (5)
C6	0.0210 (7)	0.0167 (6)	0.0251 (7)	0.0003 (5)	−0.0082 (5)	−0.0069 (5)
C7	0.0248 (7)	0.0343 (8)	0.0226 (7)	−0.0032 (6)	0.0002 (6)	−0.0107 (6)

Geometric parameters (Å, º)

S1—O1	1.465 (1)	C4—C5	1.391 (2)
S1—O2	1.464 (1)	C5—C6	1.391 (2)
S1—O3	1.445 (1)	N1—H1n1	0.86 (1)
S1—C1	1.771 (2)	N1—H1n2	0.86 (1)
O4—C4	1.354 (2)	N1—H1n3	0.86 (1)
O4—C7	1.434 (2)	C2—H2	0.95 (1)
N1—C3	1.457 (2)	C5—H5	0.95 (1)
C1—C2	1.387 (2)	C6—H6	0.95 (1)
C1—C6	1.390 (2)	C7—H71	0.95 (1)
C2—C3	1.384 (2)	C7—H72	0.95 (1)
C3—C4	1.397 (2)	C7—H73	0.95 (1)
O1—S1—O2	111.1 (1)	C3—N1—H1n1	113 (2)
O1—S1—O3	114.4 (1)	C3—N1—H1n2	112 (1)
O2—S1—O3	112.6 (1)	H1n1—N1—H1n2	104 (2)
C1—S1—O1	105.0 (1)	C3—N1—H1n3	110 (1)
C1—S1—O2	105.4 (1)	H1n1—N1—H1n3	109 (2)
C1—S1—O3	107.6 (1)	H1n2—N1—H1n3	108 (2)
C4—O4—C7	117.8 (1)	C3—C2—H2	119 (1)
C2—C1—C6	120.4 (1)	C1—C2—H2	122 (1)
C2—C1—S1	120.0 (1)	C4—C5—H5	121 (1)
C6—C1—S1	119.5 (1)	C6—C5—H5	119 (1)
C1—C2—C3	118.7 (1)	C5—C6—H6	118 (1)
C2—C3—C4	121.7 (1)	C1—C6—H6	121 (1)
C2—C3—N1	120.4 (1)	O4—C7—H71	114 (2)
C4—C3—N1	117.9 (1)	O4—C7—H72	106 (1)
O4—C4—C5	125.9 (1)	H71—C7—H72	115 (2)
O4—C4—C3	115.1 (1)	O4—C7—H73	114 (1)
C3—C4—C5	119.1 (1)	H71—C7—H73	103 (2)
C4—C5—C6	119.5 (1)	H72—C7—H73	105 (2)
C1—C6—C6	120.6 (1)
O3—S1—C1—C2	−17.6 (1)	C7—O4—C4—C3	176.1 (1)
O2—S1—C1—C2	102.8 (1)	C2—C3—C4—O4	−179.8 (1)
O1—S1—C1—C2	−139.8 (1)	N1—C3—C4—O4	−1.3 (2)
O3—S1—C1—C6	166.9 (1)	C2—C3—C4—C5	1.1 (2)
O2—S1—C1—C6	−72.7 (1)	N1—C3—C4—C5	179.6 (1)
O1—S1—C1—C6	44.7 (1)	O4—C4—C5—C6	−180.0 (1)
C6—C1—C2—C3	0.1 (2)	C3—C4—C5—C6	−1.0 (2)
S1—C1—C2—C3	−175.3 (1)	C4—C5—C6—C1	0.5 (2)
C1—C2—C3—C4	−0.7 (2)	C2—C1—C6—C5	0.0 (2)
C1—C2—C3—N1	−179.1 (1)	S1—C1—C6—C5	175.5 (1)
C7—O4—C4—C5	−4.9 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n1···O1^i	0.86 (1)	1.98 (1)	2.829 (2)	171 (2)
N1—H1n2···O2^ii	0.86 (1)	1.93 (1)	2.770 (2)	169 (2)
N1—H1n3···O1^iii	0.86 (1)	2.10 (1)	2.878 (2)	151 (2)

Symmetry codes: (i) x, y+1, z−1; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, −z+1.