Bis(2-methyl-imidazolium) fumarate dihydrate.

In the title compound, 2C(4)H(7)N(2) (+)·C(4)H(2)O(4) (2-)·2H(2)O, the asymmetric unit consists of one 2-methyl-imidazolium cation, half a fumarate dianion and one water mol-ecule. There is an inversion center at the mid-point of the central C-C bond of the fumarate anion. In the crystal structure, mol-ecules are linked into a three-dimensional network by inter-molecular N-H⋯O, O-H⋯O and weak C-H⋯O hydrogen bonds. In addition, there are weak π-π stacking inter-actions with centroid-centroid distances of 3.640 (1) Å.

Related literature

For background information on cocrystals, see: Aakeröy & Salmon (2005 ▶); Aakeröy et al. (2007 ▶); Childs & Hardcastle (2007 ▶); Childs et al. (2007 ▶).

Experimental

Crystal data

2C4H7N2 +·C4H2O4 2−·2H2O

M = 316.32

Monoclinic,

a = 8.3912 (8) Å

b = 7.3195 (7) Å

c = 14.2475 (13) Å

β = 106.624 (2)°

V = 838.50 (14) Å3

Z = 4

Mo Kα radiation

μ = 0.10 mm−1

T = 294 K

0.20 × 0.10 × 0.04 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T min = 0.970, T max = 0.996

9171 measured reflections

1920 independent reflections

1261 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.152

S = 1.06

1920 reflections

114 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.25 e Å−3

Δρmin = −0.18 e Å−3

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680903952X/lh2915sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903952X/lh2915Isup2.hkl

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

2C4H7N2+·C4H2O42−·2H2O	F(000) = 336
Mr = 316.32	Dx = 1.253 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 430 reflections
a = 8.3912 (8) Å	θ = 3.0–22.0°
b = 7.3195 (7) Å	µ = 0.10 mm−1
c = 14.2475 (13) Å	T = 294 K
β = 106.624 (2)°	Plate, colorless
V = 838.50 (14) Å3	0.20 × 0.10 × 0.04 mm
Z = 4

Bruker SMART APEX CCD area-detector diffractometer	1920 independent reflections
Radiation source: fine focus sealed Siemens Mo tube	1261 reflections with I > 2σ(I)
graphite	Rint = 0.036
0.3° wide ω exposures scans	θmax = 27.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −10→10
Tmin = 0.970, Tmax = 0.996	k = −9→9
9171 measured reflections	l = −18→18

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.152	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ2(Fo2) + (0.071P)2 + 0.1419P] where P = (Fo2 + 2Fc2)/3
1920 reflections	(Δ/σ)max = 0.027
114 parameters	Δρmax = 0.25 e Å−3
0 restraints	Δρmin = −0.18 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.

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 > 2sigma(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
C1	0.5386 (2)	0.0238 (2)	0.37212 (12)	0.0401 (4)
C2	0.5606 (2)	0.0086 (2)	0.48028 (11)	0.0428 (5)
H2	0.6685	0.0117	0.5220	0.051*
C3	0.6978 (3)	0.1228 (2)	0.10113 (13)	0.0471 (5)
C4	0.4614 (3)	0.2353 (3)	0.11177 (14)	0.0539 (5)
H4	0.3750	0.2682	0.1372	0.065*
C5	0.4689 (3)	0.2673 (3)	0.02039 (14)	0.0516 (5)
H5	0.3895	0.3266	−0.0294	0.062*
C6	0.8635 (3)	0.0358 (3)	0.12642 (17)	0.0702 (7)
H6A	0.9432	0.1142	0.1698	0.105*
H6B	0.8958	0.0159	0.0678	0.105*
H6C	0.8593	−0.0791	0.1581	0.105*
N1	0.6039 (2)	0.1456 (2)	0.16080 (11)	0.0517 (5)
H1A	0.633 (2)	0.101 (3)	0.2268 (16)	0.062*
N2	0.6165 (2)	0.1953 (2)	0.01497 (11)	0.0482 (5)
H2A	0.654 (3)	0.191 (3)	−0.0380 (18)	0.074 (7)*
O1	0.66885 (18)	0.0373 (2)	0.34674 (9)	0.0569 (4)
O2	0.39407 (17)	0.0221 (2)	0.31492 (8)	0.0556 (4)
O3	0.2028 (3)	0.3054 (3)	0.34768 (13)	0.1009 (8)
H3B	0.172 (5)	0.371 (6)	0.301 (3)	0.151*
H3A	0.256 (5)	0.221 (5)	0.335 (3)	0.151*

	U11	U22	U33	U12	U13	U23
C1	0.0536 (12)	0.0402 (9)	0.0280 (8)	0.0051 (8)	0.0144 (8)	0.0001 (7)
C2	0.0490 (12)	0.0515 (11)	0.0276 (9)	0.0012 (9)	0.0102 (7)	0.0001 (7)
C3	0.0631 (13)	0.0426 (10)	0.0375 (9)	−0.0092 (9)	0.0172 (9)	−0.0010 (8)
C4	0.0635 (14)	0.0604 (13)	0.0422 (10)	−0.0028 (11)	0.0224 (10)	0.0006 (9)
C5	0.0624 (14)	0.0513 (11)	0.0402 (10)	−0.0050 (10)	0.0132 (9)	0.0023 (8)
C6	0.0735 (17)	0.0671 (15)	0.0718 (15)	0.0029 (12)	0.0235 (13)	0.0024 (12)
N1	0.0688 (12)	0.0565 (10)	0.0318 (8)	−0.0064 (9)	0.0178 (8)	0.0032 (7)
N2	0.0685 (12)	0.0476 (9)	0.0327 (8)	−0.0111 (8)	0.0210 (8)	−0.0010 (7)
O1	0.0581 (9)	0.0826 (11)	0.0349 (7)	0.0046 (7)	0.0214 (6)	0.0103 (6)
O2	0.0570 (9)	0.0780 (10)	0.0302 (6)	0.0073 (7)	0.0100 (6)	−0.0072 (6)
O3	0.150 (2)	0.1188 (17)	0.0515 (9)	0.0793 (14)	0.0575 (12)	0.0364 (10)

C1—O1	1.249 (2)	C4—H4	0.9300
C1—O2	1.253 (2)	C5—N2	1.368 (3)
C1—C2	1.503 (2)	C5—H5	0.9300
C2—C2i	1.301 (3)	C6—H6A	0.9600
C2—H2	0.9300	C6—H6B	0.9600
C3—N1	1.325 (2)	C6—H6C	0.9600
C3—N2	1.332 (2)	N1—H1A	0.96 (2)
C3—C6	1.477 (3)	N2—H2A	0.90 (2)
C4—C5	1.342 (3)	O3—H3B	0.80 (4)
C4—N1	1.368 (3)	O3—H3A	0.81 (4)
O1—C1—O2	125.22 (15)	N2—C5—H5	126.8
O1—C1—C2	116.20 (16)	C3—C6—H6A	109.5
O2—C1—C2	118.57 (17)	C3—C6—H6B	109.5
C2i—C2—C1	124.6 (2)	H6A—C6—H6B	109.5
C2i—C2—H2	117.7	C3—C6—H6C	109.5
C1—C2—H2	117.7	H6A—C6—H6C	109.5
N1—C3—N2	107.42 (19)	H6B—C6—H6C	109.5
N1—C3—C6	126.08 (18)	C3—N1—C4	109.04 (16)
N2—C3—C6	126.5 (2)	C3—N1—H1A	123.6 (13)
C5—C4—N1	107.61 (19)	C4—N1—H1A	127.4 (13)
C5—C4—H4	126.2	C3—N2—C5	109.55 (17)
N1—C4—H4	126.2	C3—N2—H2A	123.4 (15)
C4—C5—N2	106.38 (19)	C5—N2—H2A	127.0 (15)
C4—C5—H5	126.8	H3B—O3—H3A	110 (3)
O1—C1—C2—C2i	−179.1 (2)	C5—C4—N1—C3	0.1 (2)
O2—C1—C2—C2i	0.9 (3)	N1—C3—N2—C5	0.7 (2)
N1—C4—C5—N2	0.3 (2)	C6—C3—N2—C5	−178.31 (19)
N2—C3—N1—C4	−0.5 (2)	C4—C5—N2—C3	−0.6 (2)
C6—C3—N1—C4	178.5 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O3ii	0.90 (2)	1.79 (2)	2.682 (2)	172 (2)
O3—H3B···O2iii	0.80 (4)	1.94 (4)	2.733 (2)	177 (4)
C5—H5···O1iv	0.93	2.38	3.308 (3)	175
N1—H1A···O1	0.96 (2)	1.71 (2)	2.668 (2)	173 (2)
O3—H3A···O2	0.81 (4)	1.94 (4)	2.742 (2)	176 (4)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯O3i	0.90 (2)	1.79 (2)	2.682 (2)	172 (2)
O3—H3B⋯O2ii	0.80 (4)	1.94 (4)	2.733 (2)	177 (4)
C5—H5⋯O1iii	0.93	2.38	3.308 (3)	175
N1—H1A⋯O1	0.96 (2)	1.71 (2)	2.668 (2)	173 (2)
O3—H3A⋯O2	0.81 (4)	1.94 (4)	2.742 (2)	176 (4)

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