Bis(2-methyl­imidazolium) fumarate dihydrate

Xie, Z.

doi:10.1107/S160053680903952X

organic compounds

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Volume 65| Part 11| November 2009| Page o2632

https://doi.org/10.1107/S160053680903952X

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Bis(2-methylimidazolium) fumarate dihydrate

Zhiyuan Xie ^a ^*

^aSchool of Physics and Electronic Engineering, Xiangfan University, Xiangfan 441053, Hubei, People's Republic of China
^*Correspondence e-mail: zhiyuan_xie@126.com

(Received 24 September 2009; accepted 29 September 2009; online 3 October 2009)

In the title compound, 2C₄H₇N₂⁺·C₄H₂O₄²⁻·2H₂O, the asymmetric unit consists of one 2-methylimidazolium cation, half a fumarate dianion and one water molecule. There is an inversion center at the mid-point of the central C—C bond of the fumarate anion. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N—H⋯O, O—H⋯O and weak C—H⋯O hydrogen bonds. In addition, there are weak π–π stacking interactions 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⁺·C₄H₂O₄²⁻·2H₂O
M_r = 316.32
Monoclinic, P 2₁ /n
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[F² > 2σ(F²)] = 0.051
wR(F²) = 0.152
S = 1.06
1920 reflections
114 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.18 e Å⁻³

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) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

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.

Supporting information

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

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680903952X/lh2915Isup2.hkl

checkCIF report

Comment top

Studies on cocrystals or organic salts have been expanded rapidly in recent years owing to their potential application in active pharmaceutical ingredients (Aakeröy et al., 2007; Childs et al., 2007; Hilds & Hardcastle, 2007). Herein, the crystal structure an organic salt formed by the reaction of 2-methylimidazole and fumaric acid is reported.

In the title compound (I), the asymmetric unit is composed of one 2-methylimidazolium cation, half a fumarate dianion and one water molecule. There is an inversion center at the midpoint of the C2-C2(1-x, -y, 1-z) bond. The title complex can be regarded as an organic salt according to Aakeröy & Salmon (2005). The fumaric acid molecule is deprotonated, with both the protons transferred to the imidazole N atom leading to each a fumarate dianion and an imidazolium cation (Fig.1), which can be evidenced to some extent by the delocaliztion of the carboxyl C-O bonds (C1-O1 1.249 (2)Å, C1-O2 1.253 (2)Å) and the imidazolium C-N bonds (C3-N1 1.325 (2)Å, C3-N2 1.332 (2)Å).

In the crystal packing, by a combination of two N-H···O, two O-H···O and one C-H···O hydrogen bonds (Table 1) and one π-π interaction [Cg···Cg(1-x, 1-y, -z) = 3.640 (1)Å, Cg is the centroid defined by atoms C3-C5/N1/N2], molecules in (I) are linked into a three-dimensional network (Fig.2).

Related literature top

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

Experimental top

All the reagents and solvents were used as obtained without further purification. A 1:2 molar amounts of fumaric acid (0.2 mmol, 23.2 mg) and 2-methyl-imidazole (0.4 mmol, 32.8 mg) were dissolved in 95% methanol (10 ml). The resulting solution was kept in air for one week. Plate crystals of (I) suitable for single-crystal X-ray diffraction analysis were grown by slow evaporation of the solution at the bottom of the vessel.

Structure description top

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

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); 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 (Spek, 2009).

Figures top

	Fig. 1. Molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H-bonds are shown in dashed lines. (Symmetry code (iv): 1-x, -y, 1-z).
	Fig. 2. Part of the crystal structure of (I), showing the formation of the three-dimensional network by N-H···O, O-H···O and C-H···O hydrogen-bonds and π–π stacking interactions shown as dashed lines. Hydrogen atoms not involved in the motif have been omitted for clarity.

Bis(2-methylimidazolium) fumarate dihydrate top

Crystal data top

2C₄H₇N₂⁺·C₄H₂O₄²⁻·2H₂O	F(000) = 336
M_r = 316.32	D_x = 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

Data collection top

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 monochromator	R_int = 0.036
0.3° wide ω exposures scans	θ_max = 27.5°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −10→10
T_min = 0.970, T_max = 0.996	k = −9→9
9171 measured reflections	l = −18→18

Refinement top

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(F_o²) + (0.071P)² + 0.1419P] where P = (F_o² + 2F_c²)/3
1920 reflections	(Δ/σ)_max = 0.027
114 parameters	Δρ_max = 0.25 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

2C₄H₇N₂⁺·C₄H₂O₄²⁻·2H₂O	V = 838.50 (14) Å³
M_r = 316.32	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 8.3912 (8) Å	µ = 0.10 mm⁻¹
b = 7.3195 (7) Å	T = 294 K
c = 14.2475 (13) Å	0.20 × 0.10 × 0.04 mm
β = 106.624 (2)°

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1920 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	1261 reflections with I > 2σ(I)
T_min = 0.970, T_max = 0.996	R_int = 0.036
9171 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.051	0 restraints
wR(F²) = 0.152	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.25 e Å⁻³
1920 reflections	Δρ_min = −0.18 e Å⁻³
114 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
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*

Atomic displacement parameters (Å²) top

	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)

Geometric parameters (Å, º) top

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)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º) top

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···O1^iv	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: (ii) x+1/2, −y+1/2, z−1/2; (iii) −x+1/2, y+1/2, −z+1/2; (iv) x−1/2, −y+1/2, z−1/2.

Experimental details

Crystal data
Chemical formula	2C₄H₇N₂⁺·C₄H₂O₄²⁻·2H₂O
M_r	316.32
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	294
a, b, c (Å)	8.3912 (8), 7.3195 (7), 14.2475 (13)
β (°)	106.624 (2)
V (Å³)	838.50 (14)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.10 × 0.04

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.970, 0.996
No. of measured, independent and observed [I > 2σ(I)] reflections	9171, 1920, 1261
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.152, 1.06
No. of reflections	1920
No. of parameters	114
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.18

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

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)	175.1
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) x+1/2, −y+1/2, z−1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) x−1/2, −y+1/2, z−1/2.

Acknowledgements

The author thanks Xiangfan University for financial support.

References

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