2-Ethyl-1H-imidazole-4-carboxyl-ate monohydrate.

In the title compound, C(7)H(8)N(2)O(4)·H(2)O, the imidazole N atom is protonated and one of the carboxyl-ate groups is deprontonated, forming a zwitterion. The two carboxyl groups are are approximately coplanar with the imidazole ring [O-C-C-C torsion angles = -176.8 (2) and 2.9 (4)° for one group and -4.6 (3) and 176.4 (2)° for the other] and have an intra-molecular O-H⋯O hydrogen bond between them. The water mol-ecule is linked to the organic mol-ecules via an N-H⋯O hydrogen bonds. Inter-molecular O-H⋯O and N-H⋯O hydrogen bonds are found in the crystal structure.

Related literature

For our past work based on the 2-propyl-1H-imidazole-4,5-carboxyl­ate (H3pimda) ligand, see: Yan et al. (2010 ▶); Li et al. (2010 ▶); Song et al. (2010 ▶); He et al. (2010 ▶); Fan et al. (2010 ▶). For related coordination polymers based on H3EIDC (2-ethyl-1H-imidazole-4,5-dicarboxyl­ate), see: Wang et al. (2008 ▶); Zhang et al. (2010 ▶); Li et al. (2011 ▶). For the synthesis of H3EIDC, see: Sun et al. (2006 ▶).

Experimental

Crystal data

C7H10N2O5

M = 202.17

Monoclinic,

a = 7.6132 (6) Å

b = 14.3779 (16) Å

c = 7.9396 (8) Å

β = 97.799 (1)°

V = 861.04 (15) Å3

Z = 4

Mo Kα radiation

μ = 0.13 mm−1

T = 298 K

0.50 × 0.41 × 0.40 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T min = 0.936, T max = 0.948

4224 measured reflections

1510 independent reflections

1166 reflections with I > 2σ(I)

R int = 0.031

Refinement

R[F 2 > 2σ(F 2)] = 0.038

wR(F 2) = 0.106

S = 1.05

1510 reflections

129 parameters

3 restraints

H-atom parameters constrained

Δρmax = 0.28 e Å−3

Δρmin = −0.21 e Å−3

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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 I, 1R. DOI: 10.1107/S1600536811010774/jh2272sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811010774/jh2272Isup2.hkl

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

C7H10N2O5	F(000) = 424
Mr = 202.17	Dx = 1.560 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1702 reflections
a = 7.6132 (6) Å	θ = 2.5–25.9°
b = 14.3779 (16) Å	µ = 0.13 mm−1
c = 7.9396 (8) Å	T = 298 K
β = 97.799 (1)°	Block, colorless
V = 861.04 (15) Å3	0.50 × 0.41 × 0.40 mm
Z = 4

Bruker SMART 1000 CCD area-detector diffractometer	1510 independent reflections
Radiation source: fine-focus sealed tube	1166 reflections with I > 2σ(I)
graphite	Rint = 0.031
φ and ω scans	θmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −9→8
Tmin = 0.936, Tmax = 0.948	k = −17→13
4224 measured reflections	l = −9→7

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)] = 0.038	H-atom parameters constrained
wR(F2) = 0.106	w = 1/[σ2(Fo2) + (0.047P)2 + 0.3916P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max < 0.001
1510 reflections	Δρmax = 0.28 e Å−3
129 parameters	Δρmin = −0.21 e Å−3
3 restraints	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.060 (5)

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
N1	0.4705 (2)	0.42162 (11)	0.2301 (2)	0.0314 (4)
H1	0.4860	0.4805	0.2208	0.038*
N2	0.3607 (2)	0.29056 (11)	0.2927 (2)	0.0305 (4)
H2	0.2932	0.2499	0.3308	0.037*
O1	0.7740 (2)	0.46097 (10)	0.0811 (2)	0.0517 (5)
O2	0.8238 (2)	0.31103 (10)	0.0434 (2)	0.0457 (5)
H2A	0.7770	0.2619	0.0653	0.069*
O3	0.6974 (2)	0.16119 (9)	0.1124 (2)	0.0433 (4)
O4	0.4800 (2)	0.11124 (9)	0.2502 (2)	0.0436 (4)
O1W	0.8455 (2)	0.65550 (10)	0.0862 (2)	0.0501 (5)
H1W	0.9476	0.6582	0.0543	0.075*
H2W	0.8189	0.5995	0.1057	0.075*
C1	0.7364 (3)	0.37964 (14)	0.0950 (3)	0.0356 (5)
C2	0.5789 (3)	0.35434 (13)	0.1777 (2)	0.0295 (5)
C3	0.5090 (3)	0.27125 (13)	0.2173 (2)	0.0282 (5)
C4	0.5648 (3)	0.17372 (13)	0.1935 (3)	0.0314 (5)
C5	0.3383 (3)	0.38238 (13)	0.2972 (3)	0.0310 (5)
C6	0.1908 (3)	0.43371 (15)	0.3579 (3)	0.0466 (6)
H6A	0.1212	0.4632	0.2610	0.056*
H6B	0.2403	0.4827	0.4340	0.056*
C7	0.0694 (3)	0.37559 (17)	0.4485 (3)	0.0528 (7)
H7A	0.0221	0.3257	0.3758	0.079*
H7B	−0.0259	0.4135	0.4773	0.079*
H7C	0.1345	0.3504	0.5503	0.079*

	U11	U22	U33	U12	U13	U23
N1	0.0332 (9)	0.0177 (8)	0.0455 (11)	0.0005 (7)	0.0140 (8)	0.0015 (7)
N2	0.0316 (9)	0.0200 (8)	0.0425 (10)	−0.0005 (6)	0.0145 (8)	0.0011 (7)
O1	0.0503 (10)	0.0288 (9)	0.0821 (13)	−0.0062 (7)	0.0310 (9)	0.0027 (8)
O2	0.0437 (9)	0.0295 (8)	0.0707 (11)	0.0011 (7)	0.0321 (8)	0.0009 (7)
O3	0.0479 (9)	0.0275 (8)	0.0601 (10)	0.0068 (6)	0.0272 (8)	−0.0009 (7)
O4	0.0460 (9)	0.0202 (7)	0.0690 (11)	0.0006 (6)	0.0236 (8)	0.0029 (7)
O1W	0.0479 (10)	0.0283 (8)	0.0813 (12)	−0.0006 (7)	0.0344 (9)	−0.0023 (8)
C1	0.0344 (11)	0.0281 (11)	0.0466 (13)	0.0005 (9)	0.0137 (10)	0.0017 (9)
C2	0.0306 (11)	0.0234 (10)	0.0355 (11)	0.0029 (8)	0.0087 (9)	−0.0001 (8)
C3	0.0296 (10)	0.0222 (10)	0.0340 (11)	0.0015 (8)	0.0090 (9)	−0.0005 (8)
C4	0.0337 (11)	0.0227 (10)	0.0389 (12)	0.0023 (8)	0.0092 (9)	−0.0002 (9)
C5	0.0313 (11)	0.0222 (10)	0.0414 (12)	0.0011 (8)	0.0124 (9)	0.0005 (9)
C6	0.0433 (13)	0.0273 (12)	0.0751 (17)	0.0048 (9)	0.0295 (13)	−0.0017 (11)
C7	0.0468 (14)	0.0451 (14)	0.0734 (17)	0.0080 (11)	0.0334 (13)	0.0037 (13)

N1—C5	1.327 (2)	O1W—H2W	0.8501
N1—C2	1.372 (2)	C1—C2	1.488 (3)
N1—H1	0.8600	C2—C3	1.362 (3)
N2—C5	1.332 (3)	C3—C4	1.485 (3)
N2—C3	1.376 (2)	C5—C6	1.478 (3)
N2—H2	0.8600	C6—C7	1.500 (3)
O1—C1	1.212 (2)	C6—H6A	0.9700
O2—C1	1.288 (2)	C6—H6B	0.9700
O2—H2A	0.8200	C7—H7A	0.9600
O3—C4	1.281 (2)	C7—H7B	0.9600
O4—C4	1.227 (2)	C7—H7C	0.9600
O1W—H1W	0.8500
C5—N1—C2	110.02 (16)	O4—C4—C3	118.07 (17)
C5—N1—H1	125.0	O3—C4—C3	117.11 (17)
C2—N1—H1	125.0	N1—C5—N2	107.67 (16)
C5—N2—C3	109.11 (15)	N1—C5—C6	124.74 (17)
C5—N2—H2	125.4	N2—C5—C6	127.55 (17)
C3—N2—H2	125.4	C5—C6—C7	115.01 (18)
C1—O2—H2A	109.5	C5—C6—H6A	108.5
H1W—O1W—H2W	110.3	C7—C6—H6A	108.5
O1—C1—O2	124.86 (19)	C5—C6—H6B	108.5
O1—C1—C2	119.35 (18)	C7—C6—H6B	108.5
O2—C1—C2	115.80 (17)	H6A—C6—H6B	107.5
C3—C2—N1	106.15 (16)	C6—C7—H7A	109.5
C3—C2—C1	132.84 (18)	C6—C7—H7B	109.5
N1—C2—C1	121.01 (17)	H7A—C7—H7B	109.5
C2—C3—N2	107.05 (16)	C6—C7—H7C	109.5
C2—C3—C4	132.14 (17)	H7A—C7—H7C	109.5
N2—C3—C4	120.81 (17)	H7B—C7—H7C	109.5
O4—C4—O3	124.82 (17)
C5—N1—C2—C3	−0.7 (2)	C5—N2—C3—C4	−179.30 (18)
C5—N1—C2—C1	179.02 (18)	C2—C3—C4—O4	176.4 (2)
O1—C1—C2—C3	−176.8 (2)	N2—C3—C4—O4	−3.4 (3)
O2—C1—C2—C3	2.9 (4)	C2—C3—C4—O3	−4.6 (3)
O1—C1—C2—N1	3.5 (3)	N2—C3—C4—O3	175.56 (18)
O2—C1—C2—N1	−176.74 (19)	C2—N1—C5—N2	1.3 (2)
N1—C2—C3—N2	−0.1 (2)	C2—N1—C5—C6	−176.3 (2)
C1—C2—C3—N2	−179.8 (2)	C3—N2—C5—N1	−1.3 (2)
N1—C2—C3—C4	−179.9 (2)	C3—N2—C5—C6	176.2 (2)
C1—C2—C3—C4	0.4 (4)	N1—C5—C6—C7	−172.7 (2)
C5—N2—C3—C2	0.9 (2)	N2—C5—C6—C7	10.2 (4)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O4i	0.86	1.91	2.754 (2)	168
N2—H2···O1Wii	0.86	1.89	2.751 (2)	177
O2—H2A···O3	0.82	1.63	2.452 (2)	176
O1W—H1W···O2iii	0.85	2.05	2.8863 (19)	169
O1W—H2W···O1	0.85	2.03	2.849 (2)	163

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O4i	0.86	1.91	2.754 (2)	168
N2—H2⋯O1Wii	0.86	1.89	2.751 (2)	177
O2—H2A⋯O3	0.82	1.63	2.452 (2)	176
O1W—H1W⋯O2iii	0.85	2.05	2.8863 (19)	169
O1W—H2W⋯O1	0.85	2.03	2.849 (2)	163

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