5-Carb­oxy-2-isopropyl-1H-imidazol-3-ium-4-carboxyl­ate monohydrate

Abstract

In the title compound, C₈H₁₀N₂O₄·H₂O, the imidazole N atom is protonated and one of the carboxyl­ate groups is deprotoned, forming a zwitterion. An intra­molecular O—H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds. In addition, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into two-dimensional networks parallel to (10).

Related literature

For the use of related imidazole­dicarb­oxy­lic acid structures in coordination chemistry, see: Sun et al. (2006 ▶); Merchan & Stoeckli-Evans (2007 ▶); Guo (2009 ▶); Wang & Qin (2010 ▶); Wang et al. (2010 ▶); Feng et al. (2010 ▶); Li et al. (2010 ▶). For the synthesis of the title compound, see: Alcalde et al. (1992 ▶).

Experimental

Crystal data

• C₈H₁₀N₂O₄·H₂O

• M _r = 216.20

• Monoclinic,

• a = 7.828 (2) Å

• b = 14.308 (4) Å

• c = 8.930 (2) Å

• β = 93.590 (3)°

• V = 998.2 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 0.12 mm⁻¹

• T = 298 K

• 0.40 × 0.32 × 0.28 mm

Data collection

• Bruker SMART APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.953, T _max = 0.967

• 4874 measured reflections

• 2147 independent reflections

• 1599 reflections with I > 2σ(I)

• R _int = 0.028

Refinement

• R[F ² > 2σ(F ²)] = 0.043

• wR(F ²) = 0.123

• S = 1.06

• 2147 reflections

• 140 parameters

• 3 restraints

• H-atom parameters constrained

• Δρ_max = 0.32 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811024767/lr2015Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2	0.82	1.64	2.4576 (19)	175
N1—H1⋯O5	0.86	1.83	2.6879 (19)	171
N2—H2⋯O1i	0.86	1.93	2.7619 (19)	162
O5—H5B⋯O3ii	0.85	2.03	2.8684 (19)	171
O5—H5A⋯O4iii	0.85	1.94	2.7857 (19)	173

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

supplementary crystallographic information

Comment

In the past the construction of metal complexes based on N-heterocyclic carboxylic acids has attracted much attention due to their intriguing topologies as well as their potential applications in many fields. Particular attention has been paid to the 1H-imidazole-4,5-dicarboxylic acid ligand and its analogs: (Sun et al., 2006) have synthesized the 4-carboxy-2-(pyridinium-4-yl)-1H-imidazole-5-carboxylate monohydrate; Merchan et al. (2007) have prepared the dimethylammonium 4-carboxy-1H-imidazole-5-carboxylate; (Guo, 2009) have reported the 4-carboxy-2-methyl-1H-imidazole-5-carboxylate monohydrate and (Wang & Qin, 2010) have reported the dimethylammonium 4-carboxy-2-n-propyl-1H-imidazole-5-carboxylate. All of these 1H-imidazole-4,5-dicarboxylic acid and their analogs have been used as ligands to design metal complexes and most of them are proved ideal ligands (Wang et al., 2010; Feng et al., 2010; Li et al., 2010). However, the crystal structure of 4-carboxy-2-isopropyl-1H-imidazole-5-carboxylate has not been yet determined. Keeping that in mind, we report here the preparation and crystal structure of the title compound. The crystal structure (Fig.2, Table1) is stabilized by two intramolecular and three intermolecular N—H···O and O—H···O hydrogen bonds which link the molecules into two-dimensional networks parallel to the (102) planes.

Experimental

The title compound was synthesized according to the method reported in the literature (Alcalde et al., 1992). Colourless single crystals suitable for X-ray diffraction were obtained by slow evaporation of a water solution of the compound.

Refinement

H atoms bonded to the water O atom were located in an electron density map and refined with distance restraints of O—H = 0.85 Å. Other H atoms were positioned geometrically and refined using a riding model, with C—H = 0.96—0.98 Å, N—H = 0.86 Å and O—H = 0.82 Å. U_iso(H) = kU_eq(carrier atom), where k = 1.2 for N and C_tertiary and 1.5 for O and C_methyl.

Figures

Fig. 1.

The title compound with displacement ellipsoids drawn at the 30% probability level.

Fig. 2.

A view of the crystal structure. The H-atoms not included in hydrogen bonding have been omitted for clarity.

Crystal data

C8H10N2O4·H2O	F(000) = 456
Mr = 216.20	Dx = 1.439 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1379 reflections
a = 7.828 (2) Å	θ = 2.7–25.1°
b = 14.308 (4) Å	µ = 0.12 mm−1
c = 8.930 (2) Å	T = 298 K
β = 93.590 (3)°	Block, colourless
V = 998.2 (4) Å3	0.40 × 0.32 × 0.28 mm
Z = 4

Data collection

Bruker SMART APEXII CCD area-detector diffractometer	2147 independent reflections
Radiation source: fine-focus sealed tube	1599 reflections with I > 2σ(I)
graphite	Rint = 0.028
φ and ω scans	θmax = 27.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −9→9
Tmin = 0.953, Tmax = 0.967	k = −17→18
4874 measured reflections	l = −11→7

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.043	H-atom parameters constrained
wR(F2) = 0.123	w = 1/[σ2(Fo2) + (0.059P)2 + 0.133P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
2147 reflections	Δρmax = 0.32 e Å−3
140 parameters	Δρmin = −0.19 e Å−3
3 restraints	Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.016 (3)

Special details

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 ofF2 > 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 (Ų)

	x	y	z	Uiso*/Ueq
C4	1.2174 (2)	0.88114 (12)	0.4485 (2)	0.0397 (4)
C2	1.0189 (2)	0.76673 (11)	0.29253 (18)	0.0346 (4)
C3	1.0710 (2)	0.85223 (11)	0.34578 (19)	0.0350 (4)
C6	0.6833 (2)	0.91545 (12)	0.1177 (2)	0.0413 (4)
H6	0.6971	0.9835	0.1205	0.050*
C1	1.0889 (2)	0.67085 (11)	0.3136 (2)	0.0391 (4)
C5	0.8360 (2)	0.87217 (11)	0.19793 (19)	0.0366 (4)
C7	0.5240 (2)	0.89011 (17)	0.1978 (2)	0.0593 (6)
H7A	0.5139	0.8233	0.2031	0.089*
H7B	0.4249	0.9154	0.1435	0.089*
H7C	0.5328	0.9156	0.2975	0.089*
C8	0.6644 (3)	0.88445 (16)	−0.0461 (2)	0.0622 (6)
H8A	0.7620	0.9051	−0.0971	0.093*
H8B	0.5624	0.9113	−0.0934	0.093*
H8C	0.6571	0.8175	−0.0507	0.093*
O2	1.21461 (18)	0.66102 (9)	0.41079 (17)	0.0588 (4)
O4	1.24232 (16)	0.96417 (9)	0.47291 (15)	0.0527 (4)
O3	1.31065 (17)	0.81470 (9)	0.50578 (16)	0.0521 (4)
H3	1.2783	0.7647	0.4692	0.078*
O1	1.02199 (16)	0.60794 (8)	0.23815 (16)	0.0494 (4)
N1	0.87377 (17)	0.78132 (9)	0.20091 (15)	0.0368 (3)
H1	0.8162	0.7384	0.1529	0.044*
N2	0.95551 (16)	0.91583 (9)	0.28360 (16)	0.0372 (4)
H2	0.9601	0.9752	0.2981	0.045*
O5	0.66848 (18)	0.65027 (9)	0.07026 (18)	0.0638 (5)
H5B	0.5604	0.6549	0.0562	0.096*
H5A	0.6938	0.5927	0.0646	0.096*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C4	0.0340 (9)	0.0334 (10)	0.0514 (10)	0.0000 (7)	0.0003 (7)	−0.0017 (8)
C2	0.0306 (8)	0.0264 (8)	0.0464 (9)	0.0013 (6)	−0.0014 (7)	0.0008 (7)
C3	0.0308 (8)	0.0258 (8)	0.0483 (10)	0.0020 (6)	0.0007 (7)	0.0004 (6)
C6	0.0366 (9)	0.0297 (9)	0.0565 (11)	0.0066 (7)	−0.0047 (7)	0.0023 (7)
C1	0.0346 (9)	0.0256 (9)	0.0566 (10)	0.0024 (7)	−0.0013 (7)	0.0012 (7)
C5	0.0336 (9)	0.0260 (8)	0.0499 (10)	0.0017 (7)	−0.0005 (7)	0.0001 (7)
C7	0.0405 (11)	0.0786 (16)	0.0581 (12)	0.0123 (10)	−0.0015 (9)	0.0096 (11)
C8	0.0637 (13)	0.0724 (16)	0.0502 (12)	0.0243 (12)	0.0007 (10)	0.0104 (10)
O2	0.0564 (9)	0.0348 (8)	0.0813 (10)	0.0108 (6)	−0.0258 (7)	0.0023 (6)
O4	0.0521 (8)	0.0331 (7)	0.0711 (9)	−0.0084 (6)	−0.0102 (6)	−0.0041 (6)
O3	0.0438 (8)	0.0372 (7)	0.0725 (9)	0.0015 (6)	−0.0178 (6)	−0.0031 (6)
O1	0.0450 (7)	0.0245 (6)	0.0775 (9)	0.0024 (5)	−0.0040 (6)	−0.0058 (6)
N1	0.0336 (7)	0.0242 (7)	0.0514 (8)	0.0017 (6)	−0.0070 (6)	−0.0022 (6)
N2	0.0334 (8)	0.0205 (7)	0.0570 (9)	0.0013 (5)	−0.0028 (6)	−0.0026 (6)
O5	0.0516 (8)	0.0357 (8)	0.0994 (11)	0.0046 (6)	−0.0323 (8)	−0.0154 (7)

Geometric parameters (Å, °)

C4—O4	1.221 (2)	C5—N2	1.327 (2)
C4—O3	1.285 (2)	C5—N1	1.333 (2)
C4—C3	1.481 (2)	C7—H7A	0.9600
C2—C3	1.366 (2)	C7—H7B	0.9600
C2—N1	1.374 (2)	C7—H7C	0.9600
C2—C1	1.485 (2)	C8—H8A	0.9600
C3—N2	1.375 (2)	C8—H8B	0.9600
C6—C5	1.489 (2)	C8—H8C	0.9600
C6—C7	1.520 (3)	O3—H3	0.8200
C6—C8	1.526 (3)	N1—H1	0.8600
C6—H6	0.9800	N2—H2	0.8600
C1—O1	1.222 (2)	O5—H5B	0.8500
C1—O2	1.279 (2)	O5—H5A	0.8501
O4—C4—O3	124.60 (17)	C6—C7—H7A	109.5
O4—C4—C3	119.41 (16)	C6—C7—H7B	109.5
O3—C4—C3	115.99 (15)	H7A—C7—H7B	109.5
C3—C2—N1	106.79 (14)	C6—C7—H7C	109.5
C3—C2—C1	133.16 (16)	H7A—C7—H7C	109.5
N1—C2—C1	120.04 (15)	H7B—C7—H7C	109.5
C2—C3—N2	106.13 (14)	C6—C8—H8A	109.5
C2—C3—C4	131.93 (15)	C6—C8—H8B	109.5
N2—C3—C4	121.93 (14)	H8A—C8—H8B	109.5
C5—C6—C7	109.35 (15)	C6—C8—H8C	109.5
C5—C6—C8	111.52 (14)	H8A—C8—H8C	109.5
C7—C6—C8	110.41 (17)	H8B—C8—H8C	109.5
C5—C6—H6	108.5	C4—O3—H3	109.5
C7—C6—H6	108.5	C5—N1—C2	109.54 (14)
C8—C6—H6	108.5	C5—N1—H1	125.2
O1—C1—O2	125.32 (16)	C2—N1—H1	125.2
O1—C1—C2	117.95 (16)	C5—N2—C3	110.08 (14)
O2—C1—C2	116.73 (15)	C5—N2—H2	125.0
N2—C5—N1	107.44 (14)	C3—N2—H2	125.0
N2—C5—C6	126.67 (15)	H5B—O5—H5A	107.5
N1—C5—C6	125.84 (15)
N1—C2—C3—N2	−0.31 (17)	C7—C6—C5—N2	−106.3 (2)
C1—C2—C3—N2	178.46 (17)	C8—C6—C5—N2	131.29 (19)
N1—C2—C3—C4	179.79 (16)	C7—C6—C5—N1	71.0 (2)
C1—C2—C3—C4	−1.4 (3)	C8—C6—C5—N1	−51.3 (2)
O4—C4—C3—C2	175.88 (18)	N2—C5—N1—C2	1.04 (18)
O3—C4—C3—C2	−3.9 (3)	C6—C5—N1—C2	−176.75 (15)
O4—C4—C3—N2	−4.0 (2)	C3—C2—N1—C5	−0.44 (18)
O3—C4—C3—N2	176.25 (16)	C1—C2—N1—C5	−179.40 (15)
C3—C2—C1—O1	−172.81 (18)	N1—C5—N2—C3	−1.24 (18)
N1—C2—C1—O1	5.8 (2)	C6—C5—N2—C3	176.52 (16)
C3—C2—C1—O2	7.7 (3)	C2—C3—N2—C5	0.97 (18)
N1—C2—C1—O2	−173.71 (15)	C4—C3—N2—C5	−179.12 (15)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O2	0.82	1.64	2.4576 (19)	175
N1—H1···O5	0.86	1.83	2.6879 (19)	171
N2—H2···O1i	0.86	1.93	2.7619 (19)	162
O5—H5B···O3ii	0.85	2.03	2.8684 (19)	171
O5—H5A···O4iii	0.85	1.94	2.7857 (19)	173

Symmetry codes: (i) −x+2, y+1/2, −z+1/2; (ii) x−1, −y+3/2, z−1/2; (iii) −x+2, y−1/2, −z+1/2.