Bis(2-methyl-1H-imidazol-3-ium) naphthalene-1,5-disulfonate dihydrate.

The asymmetric unit of the title organic salt, 2C(4)H(7)N(2) (+)·C(10)H(6)O(6)S(2) (2-)·2H(2)O, consists of a 2-methyl-imidazolium cation, a half of a naphthalene-1,5-disulfonate anion, which lies about a center of symmetry, and a water mol-ecule. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the cations, anions and water mol-ecules into the layers parallel to (111).

Related literature

For general background to dielectric–ferroelectric phase transitions, see: Ye et al. (2009 ▶); Zhang et al. (2009 ▶). For the structures of naphthalene-1,5-disulfonate salts with N-heterocyclic cations, see: Janczak & Perpétuo (2008 ▶); Wang et al. (2008 ▶).

Experimental

Crystal data

2C4H7N2 +·C10H6O6S2 2−·2H2O

M = 488.53

Triclinic,

a = 7.1301 (14) Å

b = 8.1773 (16) Å

c = 9.970 (2) Å

α = 75.58 (3)°

β = 75.10 (3)°

γ = 80.34 (3)°

V = 540.7 (2) Å3

Z = 1

Mo Kα radiation

μ = 0.30 mm−1

T = 293 K

0.23 × 0.22 × 0.18 mm

Data collection

Rigaku SCXmini diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.933, T max = 0.947

5695 measured reflections

2475 independent reflections

1490 reflections with I > 2σ(I)

R int = 0.059

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.107

S = 0.94

2475 reflections

154 parameters

3 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.20 e Å−3

Δρmin = −0.33 e Å−3

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812019149/yk2053sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812019149/yk2053Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812019149/yk2053Isup3.cml

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

2C4H7N2+·C10H6O6S22−·2H2O	Z = 1
Mr = 488.53	F(000) = 256
Triclinic, P1	Dx = 1.500 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.1301 (14) Å	Cell parameters from 3638 reflections
b = 8.1773 (16) Å	θ = 3.0–27.5°
c = 9.970 (2) Å	µ = 0.30 mm−1
α = 75.58 (3)°	T = 293 K
β = 75.10 (3)°	Block, colourless
γ = 80.34 (3)°	0.23 × 0.22 × 0.18 mm
V = 540.7 (2) Å3

Rigaku SCXmini diffractometer	2475 independent reflections
Radiation source: fine-focus sealed tube	1490 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.059
Detector resolution: 13.6612 pixels mm-1	θmax = 27.5°, θmin = 3.3°
ω scans	h = −9→9
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −10→10
Tmin = 0.933, Tmax = 0.947	l = −12→12
5695 measured 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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107	H atoms treated by a mixture of independent and constrained refinement
S = 0.94	w = 1/[σ2(Fo2) + (0.0396P)2] where P = (Fo2 + 2Fc2)/3
2475 reflections	(Δ/σ)max = 0.005
154 parameters	Δρmax = 0.20 e Å−3
3 restraints	Δρmin = −0.33 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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
O4	0.7815 (4)	0.0540 (4)	0.1408 (3)	0.0873 (9)
C9	0.7423 (4)	0.6967 (3)	−0.0199 (3)	0.0419 (7)
H9A	0.8089	0.7809	−0.0115	0.050*
S1	0.13194 (10)	0.66733 (9)	0.23893 (7)	0.0342 (2)
O3	0.2455 (3)	0.6595 (2)	0.33926 (19)	0.0438 (5)
O2	0.1153 (3)	0.8363 (2)	0.1501 (2)	0.0481 (5)
C7	0.4534 (3)	0.5560 (3)	0.0451 (2)	0.0255 (5)
C6	0.2599 (3)	0.5340 (3)	0.1233 (2)	0.0271 (6)
O1	−0.0547 (2)	0.6045 (2)	0.3027 (2)	0.0501 (5)
N2	0.4574 (3)	0.1263 (3)	0.3230 (2)	0.0410 (6)
H2B	0.5580	0.0903	0.2647	0.049*
N1	0.2739 (3)	0.2647 (3)	0.4672 (2)	0.0438 (6)
H1D	0.2318	0.3366	0.5212	0.053*
C2	0.4508 (4)	0.2493 (3)	0.3875 (3)	0.0342 (6)
C8	0.5575 (4)	0.6821 (3)	0.0549 (3)	0.0349 (6)
H8A	0.4977	0.7567	0.1140	0.042*
C5	0.1658 (4)	0.4121 (3)	0.1091 (3)	0.0375 (7)
H5C	0.0378	0.4008	0.1597	0.045*
C3	0.2826 (4)	0.0645 (4)	0.3619 (3)	0.0571 (9)
H3A	0.2496	−0.0228	0.3308	0.069*
C1	0.6089 (4)	0.3484 (4)	0.3718 (3)	0.0500 (8)
H1A	0.6461	0.3283	0.4610	0.075*
H1B	0.5664	0.4669	0.3429	0.075*
H1C	0.7188	0.3156	0.3012	0.075*
C4	0.1682 (5)	0.1513 (4)	0.4521 (3)	0.0565 (9)
H4A	0.0386	0.1372	0.4970	0.068*
H4B	0.876 (4)	−0.014 (4)	0.158 (3)	0.083 (13)*
H4C	0.796 (4)	0.096 (4)	0.056 (2)	0.069 (11)*

	U11	U22	U33	U12	U13	U23
O4	0.0703 (17)	0.107 (2)	0.0409 (17)	0.0527 (15)	0.0101 (13)	−0.0005 (15)
C9	0.0391 (16)	0.0428 (18)	0.0478 (19)	−0.0129 (13)	0.0012 (14)	−0.0228 (14)
S1	0.0311 (4)	0.0392 (4)	0.0294 (4)	0.0027 (3)	0.0011 (3)	−0.0144 (3)
O3	0.0459 (11)	0.0558 (13)	0.0349 (11)	0.0010 (9)	−0.0114 (10)	−0.0213 (9)
O2	0.0517 (12)	0.0362 (12)	0.0419 (12)	0.0143 (9)	0.0011 (10)	−0.0067 (9)
C7	0.0236 (13)	0.0277 (14)	0.0237 (14)	0.0011 (10)	−0.0050 (11)	−0.0058 (10)
C6	0.0269 (13)	0.0310 (14)	0.0219 (14)	−0.0001 (11)	−0.0032 (11)	−0.0075 (11)
O1	0.0318 (11)	0.0682 (14)	0.0485 (13)	−0.0118 (9)	0.0141 (9)	−0.0293 (10)
N2	0.0377 (13)	0.0429 (15)	0.0381 (14)	−0.0014 (11)	0.0069 (11)	−0.0192 (11)
N1	0.0426 (14)	0.0420 (15)	0.0422 (15)	−0.0042 (11)	0.0096 (12)	−0.0209 (11)
C2	0.0340 (15)	0.0357 (16)	0.0281 (16)	−0.0021 (12)	−0.0008 (13)	−0.0059 (12)
C8	0.0340 (15)	0.0366 (16)	0.0367 (16)	−0.0023 (12)	−0.0023 (13)	−0.0194 (12)
C5	0.0231 (14)	0.0485 (18)	0.0402 (17)	−0.0082 (12)	0.0031 (13)	−0.0162 (13)
C3	0.057 (2)	0.048 (2)	0.066 (2)	−0.0220 (16)	0.0103 (18)	−0.0273 (17)
C1	0.0377 (17)	0.060 (2)	0.055 (2)	−0.0064 (15)	−0.0092 (15)	−0.0183 (16)
C4	0.0457 (18)	0.052 (2)	0.068 (2)	−0.0221 (15)	0.0142 (17)	−0.0241 (17)

O4—H4B	0.824 (17)	N2—H2B	0.8600
O4—H4C	0.816 (16)	N1—C2	1.311 (3)
C9—C8	1.346 (3)	N1—C4	1.347 (3)
C9—C5i	1.382 (3)	N1—H1D	0.8600
C9—H9A	0.9300	C2—C1	1.451 (3)
S1—O3	1.4237 (18)	C8—H8A	0.9300
S1—O1	1.4392 (19)	C5—C9i	1.382 (3)
S1—O2	1.4483 (19)	C5—H5C	0.9300
S1—C6	1.761 (2)	C3—C4	1.313 (4)
C7—C8	1.402 (3)	C3—H3A	0.9300
C7—C7i	1.410 (4)	C1—H1A	0.9600
C7—C6	1.415 (3)	C1—H1B	0.9600
C6—C5	1.345 (3)	C1—H1C	0.9600
N2—C2	1.310 (3)	C4—H4A	0.9300
N2—C3	1.351 (3)
H4B—O4—H4C	112 (2)	N2—C2—N1	106.4 (2)
C8—C9—C5i	120.6 (2)	N2—C2—C1	126.3 (2)
C8—C9—H9A	119.7	N1—C2—C1	127.3 (2)
C5i—C9—H9A	119.7	C9—C8—C7	121.1 (2)
O3—S1—O1	113.33 (12)	C9—C8—H8A	119.5
O3—S1—O2	111.00 (12)	C7—C8—H8A	119.5
O1—S1—O2	112.51 (12)	C6—C5—C9i	120.6 (2)
O3—S1—C6	107.66 (11)	C6—C5—H5C	119.7
O1—S1—C6	106.15 (12)	C9i—C5—H5C	119.7
O2—S1—C6	105.65 (11)	C4—C3—N2	106.8 (3)
C8—C7—C7i	118.6 (3)	C4—C3—H3A	126.6
C8—C7—C6	123.1 (2)	N2—C3—H3A	126.6
C7i—C7—C6	118.3 (3)	C2—C1—H1A	109.5
C5—C6—C7	120.8 (2)	C2—C1—H1B	109.5
C5—C6—S1	117.62 (19)	H1A—C1—H1B	109.5
C7—C6—S1	121.57 (18)	C2—C1—H1C	109.5
C2—N2—C3	109.9 (2)	H1A—C1—H1C	109.5
C2—N2—H2B	125.1	H1B—C1—H1C	109.5
C3—N2—H2B	125.1	C3—C4—N1	107.1 (3)
C2—N1—C4	109.9 (2)	C3—C4—H4A	126.5
C2—N1—H1D	125.1	N1—C4—H4A	126.5
C4—N1—H1D	125.1

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4C···O2i	0.82 (2)	1.95 (2)	2.754 (3)	167 (3)
O4—H4B···O2ii	0.82 (2)	1.92 (2)	2.730 (3)	166 (3)
N1—H1D···O1iii	0.86	2.00	2.768 (3)	149
N2—H2B···O4	0.86	1.78	2.628 (3)	169

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4C⋯O2i	0.82 (2)	1.95 (2)	2.754 (3)	167 (3)
O4—H4B⋯O2ii	0.82 (2)	1.92 (2)	2.730 (3)	166 (3)
N1—H1D⋯O1iii	0.86	2.00	2.768 (3)	149
N2—H2B⋯O4	0.86	1.78	2.628 (3)	169

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