Bis(5,6-dicarboxy-benzimidazolium) sulfate monohydrate.

In the title compound, 2C(9)H(7)N(2)O(4) (+)·SO(4) (2-)·H(2)O, the sulfate S atom and the water O atom reside on a crystallographic twofold axis. In the crystal, the component species are linked by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network structure. An intramol-ecular O-H⋯O link is seen in the cation.

Related literature

For a related structure that contains a benzimidazole mol­ecule, see: Gao et al. (2008 ▶). For the pharmacokinetics of an anti­allergic benzimidazole derivative, see: Sakai et al. (1989 ▶). For the synthesis and chemoluminescence of an amino drivative, see: White & Matsuo (1967 ▶).

Experimental

Crystal data

2C9H7N2O4 +·SO4 2−·H2O

M = 528.41

Orthorhombic,

a = 14.691 (3) Å

b = 7.7968 (17) Å

c = 17.983 (4) Å

V = 2059.8 (8) Å3

Z = 4

Mo Kα radiation

μ = 0.24 mm−1

T = 296 K

0.12 × 0.11 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T min = 0.971, T max = 0.976

11525 measured reflections

2413 independent reflections

1994 reflections with I > 2σ(I)

R int = 0.060

Refinement

R[F 2 > 2σ(F 2)] = 0.048

wR(F 2) = 0.138

S = 1.00

2413 reflections

168 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.46 e Å−3

Δρmin = −0.40 e Å−3

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809018182/si2172sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809018182/si2172Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

2C9H7N2O4+·SO42−·H2O	F(000) = 1088
Mr = 528.41	Dx = 1.704 Mg m−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 2413 reflections
a = 14.691 (3) Å	θ = 2.3–25.0°
b = 7.7968 (17) Å	µ = 0.24 mm−1
c = 17.983 (4) Å	T = 296 K
V = 2059.8 (8) Å3	Block, colorless
Z = 4	0.12 × 0.11 × 0.10 mm

Bruker SMART CCD area-detector diffractometer	2413 independent reflections
Radiation source: fine-focus sealed tube	1994 reflections with I > 2σ(I)
graphite	Rint = 0.060
φ and ω scans	θmax = 27.8°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −17→16
Tmin = 0.971, Tmax = 0.976	k = −9→9
11525 measured reflections	l = −21→17

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.138	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ2(Fo2) + (0.0847P)2 + 0.8915P] where P = (Fo2 + 2Fc2)/3
2413 reflections	(Δ/σ)max < 0.001
168 parameters	Δρmax = 0.46 e Å−3
0 restraints	Δρmin = −0.40 e Å−3

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq
O1	0.35417 (10)	0.1890 (2)	0.09502 (8)	0.0418 (4)
H28	0.3685	0.1903	0.1408	0.050*
O2	0.22201 (11)	0.2483 (3)	0.15019 (8)	0.0553 (5)
O3	0.00994 (12)	0.3035 (2)	0.08983 (10)	0.0586 (5)
O4	0.08286 (11)	0.05673 (19)	0.07644 (9)	0.0474 (4)
H21	0.0465	0.0172	0.1089	0.057*
N1	0.29633 (11)	0.4817 (2)	−0.16017 (8)	0.0344 (4)
H25	0.3535	0.4982	−0.1718	0.041*
N2	0.15053 (11)	0.5073 (2)	−0.17520 (9)	0.0358 (4)
H22	0.0969	0.5355	−0.1962	0.043*
C1	0.26786 (14)	0.2354 (2)	0.09487 (10)	0.0339 (4)
C2	0.23266 (12)	0.2806 (2)	0.01950 (9)	0.0280 (4)
C3	0.29283 (11)	0.3365 (2)	−0.03408 (10)	0.0293 (4)
H3A	0.3554	0.3271	−0.0276	0.035*
C4	0.25595 (12)	0.4077 (2)	−0.09819 (9)	0.0282 (4)
C5	0.23151 (14)	0.5390 (3)	−0.20452 (11)	0.0381 (4)
H5A	0.2413	0.5936	−0.2498	0.046*
C6	0.16218 (12)	0.4236 (2)	−0.10814 (10)	0.0295 (4)
C7	0.10081 (12)	0.3636 (2)	−0.05544 (10)	0.0316 (4)
H7A	0.0383	0.3721	−0.0626	0.038*
C8	0.13689 (12)	0.2909 (2)	0.00784 (10)	0.0301 (4)
C9	0.07088 (12)	0.2201 (3)	0.06351 (11)	0.0345 (4)
S1	0.0000	−0.14201 (8)	0.2500	0.0295 (2)
O9	0.07896 (13)	−0.2429 (2)	0.22937 (9)	0.0630 (6)
O11	−0.02520 (10)	−0.0310 (2)	0.18688 (9)	0.0533 (5)
O1W	0.0000	0.3439 (3)	0.2500	0.0540 (6)
H1WA	−0.024 (5)	0.266 (8)	0.286 (3)	0.20 (3)*

	U11	U22	U33	U12	U13	U23
O1	0.0398 (8)	0.0540 (9)	0.0318 (7)	0.0075 (6)	−0.0091 (6)	0.0022 (6)
O2	0.0509 (9)	0.0893 (13)	0.0258 (7)	0.0019 (9)	0.0010 (6)	−0.0032 (7)
O3	0.0511 (10)	0.0602 (10)	0.0645 (11)	0.0225 (8)	0.0302 (8)	0.0198 (9)
O4	0.0501 (9)	0.0412 (8)	0.0510 (9)	0.0022 (7)	0.0229 (7)	0.0079 (7)
N1	0.0301 (8)	0.0445 (9)	0.0285 (8)	−0.0057 (7)	0.0029 (6)	0.0030 (6)
N2	0.0331 (8)	0.0436 (9)	0.0306 (8)	−0.0038 (7)	−0.0061 (6)	0.0050 (7)
C1	0.0392 (10)	0.0365 (10)	0.0260 (9)	−0.0010 (8)	−0.0034 (7)	−0.0017 (7)
C2	0.0283 (8)	0.0305 (9)	0.0253 (8)	0.0027 (7)	−0.0014 (6)	−0.0028 (6)
C3	0.0239 (8)	0.0355 (10)	0.0284 (8)	−0.0007 (7)	−0.0010 (6)	−0.0025 (7)
C4	0.0264 (8)	0.0330 (9)	0.0252 (8)	−0.0035 (7)	0.0010 (6)	−0.0035 (7)
C5	0.0404 (10)	0.0445 (11)	0.0295 (9)	−0.0061 (9)	−0.0012 (8)	0.0035 (8)
C6	0.0281 (8)	0.0328 (9)	0.0275 (8)	−0.0020 (7)	−0.0039 (6)	−0.0003 (7)
C7	0.0222 (8)	0.0381 (10)	0.0345 (9)	−0.0011 (7)	0.0002 (7)	0.0012 (7)
C8	0.0292 (8)	0.0321 (9)	0.0291 (9)	0.0009 (7)	0.0040 (7)	−0.0014 (7)
C9	0.0287 (9)	0.0426 (11)	0.0323 (9)	0.0032 (7)	0.0055 (7)	0.0038 (8)
S1	0.0309 (3)	0.0334 (4)	0.0243 (3)	0.000	0.0043 (2)	0.000
O9	0.0814 (13)	0.0702 (12)	0.0374 (8)	0.0449 (10)	0.0205 (8)	0.0090 (8)
O11	0.0300 (7)	0.0781 (11)	0.0517 (9)	0.0056 (8)	0.0054 (6)	0.0308 (8)
O1W	0.0597 (16)	0.0487 (14)	0.0538 (15)	0.000	−0.0195 (11)	0.000

O1—C1	1.319 (2)	C2—C8	1.425 (2)
O1—H28	0.8499	C3—C4	1.389 (3)
O2—C1	1.205 (2)	C3—H3A	0.9300
O3—C9	1.204 (2)	C4—C6	1.395 (3)
O4—C9	1.306 (3)	C5—H5A	0.9300
O4—H21	0.8496	C6—C7	1.389 (3)
N1—C5	1.320 (3)	C7—C8	1.377 (3)
N1—C4	1.388 (2)	C7—H7A	0.9300
N1—H25	0.8747	C8—C9	1.499 (2)
N2—C5	1.325 (3)	S1—O9i	1.4498 (16)
N2—C6	1.382 (2)	S1—O9	1.4498 (16)
N2—H22	0.9011	S1—O11i	1.4745 (15)
C1—C2	1.493 (2)	S1—O11	1.4745 (15)
C2—C3	1.379 (2)	O1W—H1WA	0.95 (6)
C1—O1—H28	103.7	N1—C5—H5A	124.9
C9—O4—H21	113.0	N2—C5—H5A	124.9
C5—N1—C4	108.51 (16)	N2—C6—C7	132.38 (17)
C5—N1—H25	119.9	N2—C6—C4	106.03 (15)
C4—N1—H25	131.5	C7—C6—C4	121.58 (17)
C5—N2—C6	108.92 (16)	C8—C7—C6	116.90 (17)
C5—N2—H22	124.9	C8—C7—H7A	121.6
C6—N2—H22	126.1	C6—C7—H7A	121.6
O2—C1—O1	123.95 (17)	C7—C8—C2	121.67 (16)
O2—C1—C2	122.41 (18)	C7—C8—C9	117.03 (16)
O1—C1—C2	113.55 (16)	C2—C8—C9	121.30 (16)
C3—C2—C8	120.82 (16)	O3—C9—O4	123.86 (18)
C3—C2—C1	119.15 (16)	O3—C9—C8	122.97 (18)
C8—C2—C1	119.28 (16)	O4—C9—C8	113.02 (16)
C2—C3—C4	117.14 (16)	O9i—S1—O9	114.29 (17)
C2—C3—H3A	121.4	O9i—S1—O11i	108.80 (9)
C4—C3—H3A	121.4	O9—S1—O11i	108.33 (10)
N1—C4—C3	131.72 (17)	O9i—S1—O11	108.33 (10)
N1—C4—C6	106.39 (15)	O9—S1—O11	108.80 (9)
C3—C4—C6	121.81 (16)	O11i—S1—O11	108.15 (16)
N1—C5—N2	110.14 (17)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O3i	0.96 (6)	2.26 (5)	2.9012 (11)	123.6
O1W—H1WA···O11i	0.96 (6)	2.47 (6)	3.1575 (16)	128.4
O4—H21···O11	0.85	1.79	2.6330 (11)	169
N2—H22···O1Wii	0.90	1.96	2.8365 (10)	163
N1—H25···O11iii	0.88	1.82	2.6931 (12)	175
O1—H28···O9iv	0.85	1.84	2.6616 (11)	161
C5—H5A···O2v	0.93	2.20	3.098 (3)	162

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H22⋯O1Wii	0.90	1.96	2.8365 (10)	163
N1—H25⋯O11iii	0.88	1.82	2.6931 (12)	175
C5—H5A⋯O2v	0.93	2.20	3.098 (3)	162
O1—H28⋯O9iv	0.85	1.84	2.6616 (11)	161
O4—H21⋯O11	0.85	1.79	2.6330 (11)	169
O1W—H1WA⋯O3i	0.96 (6)	2.26 (5)	2.9012 (11)	123.6
O1W—H1WA⋯O11i	0.96 (6)	2.47 (6)	3.1575 (16)	128.4

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .