1H-Imidazol-3-ium-4-carboxyl-ate.

In the title compound, C(4)H(4)N(2)O(2), both imidazole N atoms are protonated and carboxyl-ate group is deprotonated, resulting in a zwitterion. The mol-ecule is essentially planar, with an r.m.s. deviation of 0.012 (1) Å. In the crystal, N-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance = 3.674 (2) Å] between the imidazole rings link the mol-ecules into a three-dimensional supra-molecular network.

Related literature

For general background to the construction of coordination polymers based on 1H-imidazole-4,5-dicarb­oxy­lic acid, see: Alkordi, Liu et al. (2008 ▶); Alkordi, Brant et al. (2009 ▶); Gu et al. (2010 ▶); Lu et al. (2006 ▶); Nouar et al. (2009 ▶); Wang et al. (2010 ▶). For related complexes with 1H-imidazole-4-carb­oxy­lic acid, see: Haggag (2005 ▶); Starosta & Leciejewicz (2006 ▶); Gryz et al. (2007 ▶); Yin et al. (2009 ▶); Shuai et al. (2011 ▶); Zheng et al. (2011 ▶). For the synthesis of 1H-imidazole-4-carb­oxy­lic acid, see: Davis et al. (1982 ▶).

Experimental

Crystal data

C4H4N2O2

M = 112.09

Orthorhombic,

a = 10.474 (6) Å

b = 11.676 (7) Å

c = 3.674 (2) Å

V = 449.3 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.14 mm−1

T = 298 K

0.25 × 0.21 × 0.18 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.967, T max = 0.976

2280 measured reflections

510 independent reflections

480 reflections with I > 2σ(I)

R int = 0.023

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.083

S = 1.10

510 reflections

73 parameters

1 restraint

H-atom parameters constrained

Δρmax = 0.12 e Å−3

Δρmin = −0.19 e Å−3

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); 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 datablock(s) I, global. DOI: 10.1107/S1600536811052998/ld2040sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811052998/ld2040Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811052998/ld2040Isup3.cml

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

C4H4N2O2	F(000) = 232
Mr = 112.09	Dx = 1.657 Mg m−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 1380 reflections
a = 10.474 (6) Å	θ = 2.6–27.0°
b = 11.676 (7) Å	µ = 0.14 mm−1
c = 3.674 (2) Å	T = 298 K
V = 449.3 (5) Å3	Block, colourless
Z = 4	0.25 × 0.21 × 0.18 mm

Bruker APEXII CCD area-detector diffractometer	510 independent reflections
Radiation source: fine-focus sealed tube	480 reflections with I > 2σ(I)
graphite	Rint = 0.023
phi and ω scans	θmax = 26.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.967, Tmax = 0.976	k = −14→12
2280 measured reflections	l = −4→4

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.083	H-atom parameters constrained
S = 1.10	w = 1/[σ2(Fo2) + (0.0578P)2 + 0.0406P] where P = (Fo2 + 2Fc2)/3
510 reflections	(Δ/σ)max < 0.001
73 parameters	Δρmax = 0.12 e Å−3
1 restraint	Δρmin = −0.19 e Å−3

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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
C2	0.15183 (19)	0.33109 (16)	0.6250 (7)	0.0265 (5)
C1	0.20900 (19)	0.44287 (17)	0.5153 (6)	0.0268 (5)
N2	0.10851 (15)	0.15065 (14)	0.7501 (6)	0.0302 (5)
H2	0.1149	0.0774	0.7660	0.036*
C4	0.0113 (2)	0.21278 (18)	0.8693 (7)	0.0301 (5)
H4	−0.0610	0.1844	0.9853	0.036*
O2	0.31910 (13)	0.43682 (12)	0.3734 (5)	0.0361 (5)
O1	0.14526 (14)	0.53104 (13)	0.5736 (6)	0.0367 (5)
N1	0.03417 (16)	0.32279 (14)	0.7956 (6)	0.0284 (5)
H1	−0.0158	0.3791	0.8456	0.034*
C3	0.1970 (2)	0.22218 (17)	0.5977 (7)	0.0280 (5)
H3	0.2743	0.2003	0.4940	0.034*

	U11	U22	U33	U12	U13	U23
C2	0.0254 (9)	0.0223 (10)	0.0320 (13)	0.0003 (8)	−0.0016 (10)	0.0003 (10)
C1	0.0295 (11)	0.0190 (9)	0.0319 (13)	0.0011 (8)	−0.0047 (9)	0.0035 (9)
N2	0.0323 (9)	0.0181 (8)	0.0401 (11)	−0.0007 (7)	−0.0033 (9)	0.0011 (9)
C4	0.0275 (10)	0.0271 (10)	0.0358 (14)	−0.0035 (8)	−0.0004 (9)	0.0032 (11)
O2	0.0324 (8)	0.0235 (7)	0.0524 (12)	−0.0013 (6)	0.0078 (8)	0.0043 (9)
O1	0.0352 (8)	0.0203 (7)	0.0545 (12)	0.0047 (6)	−0.0018 (8)	0.0025 (9)
N1	0.0279 (9)	0.0203 (8)	0.0371 (11)	0.0024 (7)	−0.0016 (9)	−0.0004 (8)
C3	0.0261 (9)	0.0222 (10)	0.0357 (14)	−0.0005 (8)	−0.0022 (10)	0.0017 (10)

C2—C3	1.361 (3)	N2—C3	1.368 (3)
C2—N1	1.386 (3)	N2—H2	0.8600
C2—C1	1.491 (3)	C4—N1	1.334 (3)
C1—O1	1.246 (3)	C4—H4	0.9300
C1—O2	1.267 (3)	N1—H1	0.8600
N2—C4	1.324 (3)	C3—H3	0.9300
C3—C2—N1	106.10 (17)	N2—C4—N1	108.81 (19)
C3—C2—C1	131.2 (2)	N2—C4—H4	125.6
N1—C2—C1	122.71 (17)	N1—C4—H4	125.6
O1—C1—O2	127.19 (19)	C4—N1—C2	108.57 (17)
O1—C1—C2	117.49 (18)	C4—N1—H1	125.7
O2—C1—C2	115.32 (18)	C2—N1—H1	125.7
C4—N2—C3	108.78 (17)	C2—C3—N2	107.74 (19)
C4—N2—H2	125.6	C2—C3—H3	126.1
C3—N2—H2	125.6	N2—C3—H3	126.1
C3—C2—C1—O1	−180.0 (3)	C3—C2—N1—C4	0.5 (3)
N1—C2—C1—O1	−1.9 (3)	C1—C2—N1—C4	−178.0 (2)
C3—C2—C1—O2	−0.5 (4)	N1—C2—C3—N2	−0.2 (3)
N1—C2—C1—O2	177.6 (2)	C1—C2—C3—N2	178.1 (2)
C3—N2—C4—N1	0.4 (3)	C4—N2—C3—C2	−0.1 (3)
N2—C4—N1—C2	−0.6 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O2i	0.86	1.82	2.648 (2)	160.
N1—H1···O1ii	0.86	1.91	2.736 (2)	161.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O2i	0.86	1.82	2.648 (2)	160
N1—H1⋯O1ii	0.86	1.91	2.736 (2)	161

Symmetry codes: (i) ; (ii) .