1H-Pyrazol-2-ium hydrogen oxalate.

In the title compound, C(3)H(5)N(2) (+)·C(2)HO(4) (-), the anions form centrosymmetric dimers through cyclic O-H⋯O hydrogen-bonding associations [graph set R(2) (2)(10)]. These dimers are then linked through a cyclic R(4) (2)(10) N-H⋯O hydrogen-bonding association involving two cations and the carboxyl O-atom acceptors of separate anions, giving chain structures extending across the (111) plane.

Related literature

For general background to ferroelectric organic frameworks, see: Fu et al. (2009 ▶); Ye et al. (2006 ▶); Zhang et al. (2008 ▶, 2010 ▶). For graph-set analysis, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C3H5N2 +·C2HO4 −

M = 158.12

Triclinic,

a = 3.7286 (7) Å

b = 9.836 (2) Å

c = 10.487 (2) Å

α = 117.35 (3)°

β = 97.01 (3)°

γ = 93.65 (3)°

V = 335.92 (14) Å3

Z = 2

Mo Kα radiation

μ = 0.14 mm−1

T = 293 K

0.26 × 0.22 × 0.14 mm

Data collection

Rigaku SCXmini CCD diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.965, T max = 0.993

3484 measured reflections

1527 independent reflections

702 reflections with I > 2σ(I)

R int = 0.063

Refinement

R[F 2 > 2σ(F 2)] = 0.095

wR(F 2) = 0.285

S = 1.07

1527 reflections

101 parameters

H-atom parameters constrained

Δρmax = 0.48 e Å−3

Δρmin = −0.29 e Å−3

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812023136/zs2209sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812023136/zs2209Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812023136/zs2209Isup3.cml

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

C3H5N2+·C2HO4−	Z = 2
Mr = 158.12	F(000) = 164
Triclinic, P1	Dx = 1.563 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 3.7286 (7) Å	Cell parameters from 1527 reflections
b = 9.836 (2) Å	θ = 2.4–27.5°
c = 10.487 (2) Å	µ = 0.14 mm−1
α = 117.35 (3)°	T = 293 K
β = 97.01 (3)°	Sheet, colourless
γ = 93.65 (3)°	0.26 × 0.22 × 0.14 mm
V = 335.92 (14) Å3

Rigaku SCXmini CCD diffractometer	1527 independent reflections
Radiation source: fine-focus sealed tube	702 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.063
CCD_Profile_fitting scans	θmax = 27.5°, θmin = 3.9°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	h = −4→4
Tmin = 0.965, Tmax = 0.993	k = −12→12
3484 measured reflections	l = −13→13

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)] = 0.095	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.285	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.1349P)2 + 0.0952P] where P = (Fo2 + 2Fc2)/3
1527 reflections	(Δ/σ)max < 0.001
101 parameters	Δρmax = 0.48 e Å−3
0 restraints	Δρmin = −0.29 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
N1	1.0872 (11)	0.0136 (5)	0.3057 (4)	0.0416 (11)
H1A	1.1595	−0.0585	0.3230	0.050*
N2	1.1523 (11)	0.1643 (5)	0.3992 (4)	0.0412 (11)
H2A	1.2729	0.2054	0.4865	0.049*
C1	0.9992 (15)	0.2395 (6)	0.3352 (6)	0.0493 (15)
H1	1.0047	0.3461	0.3773	0.059*
C2	0.8307 (15)	0.1355 (7)	0.1967 (6)	0.0505 (15)
H2	0.7020	0.1567	0.1277	0.061*
C3	0.8931 (15)	−0.0076 (7)	0.1818 (6)	0.0477 (14)
H3	0.8131	−0.1021	0.0993	0.057*
O1	0.3997 (10)	0.8001 (4)	0.3600 (3)	0.0475 (10)
O2	0.6353 (11)	0.5351 (4)	0.3418 (4)	0.0577 (12)
O3	0.0807 (11)	0.6588 (4)	0.1355 (4)	0.0581 (11)
O4	0.3270 (11)	0.4012 (4)	0.1179 (4)	0.0554 (11)
H4	0.1905	0.4187	0.0612	0.083*
C4	0.2907 (14)	0.6762 (6)	0.2446 (5)	0.0402 (13)
C5	0.4374 (14)	0.5304 (6)	0.2400 (5)	0.0425 (13)

	U11	U22	U33	U12	U13	U23
N1	0.049 (3)	0.033 (2)	0.041 (2)	0.0045 (19)	−0.0029 (19)	0.019 (2)
N2	0.048 (3)	0.034 (2)	0.031 (2)	0.005 (2)	−0.0023 (19)	0.0087 (19)
C1	0.053 (3)	0.045 (3)	0.056 (4)	0.011 (3)	0.006 (3)	0.029 (3)
C2	0.053 (4)	0.052 (4)	0.048 (3)	0.010 (3)	−0.002 (3)	0.027 (3)
C3	0.047 (3)	0.042 (3)	0.041 (3)	0.004 (2)	−0.006 (2)	0.011 (3)
O1	0.062 (2)	0.033 (2)	0.037 (2)	0.0087 (17)	−0.0074 (17)	0.0110 (18)
O2	0.076 (3)	0.043 (2)	0.045 (2)	0.0122 (19)	−0.0127 (19)	0.018 (2)
O3	0.077 (3)	0.042 (2)	0.044 (2)	0.0123 (19)	−0.0126 (19)	0.0155 (19)
O4	0.075 (3)	0.032 (2)	0.045 (2)	0.0098 (19)	−0.0082 (19)	0.0113 (19)
C4	0.047 (3)	0.032 (3)	0.035 (3)	0.005 (2)	0.005 (2)	0.011 (2)
C5	0.050 (3)	0.033 (3)	0.039 (3)	0.003 (2)	0.004 (3)	0.013 (3)

N1—C3	1.325 (6)	C2—H2	0.9300
N1—N2	1.333 (5)	C3—H3	0.9300
N1—H1A	0.8601	O1—C4	1.256 (6)
N2—C1	1.319 (6)	O2—C5	1.202 (6)
N2—H2A	0.8600	O3—C4	1.239 (6)
C1—C2	1.372 (7)	O4—C5	1.317 (6)
C1—H1	0.9300	O4—H4	0.8200
C2—C3	1.380 (8)	C4—C5	1.549 (7)
C3—N1—N2	109.3 (4)	C3—C2—H2	127.4
C3—N1—H1A	125.3	N1—C3—C2	108.0 (5)
N2—N1—H1A	125.4	N1—C3—H3	126.0
C1—N2—N1	108.4 (4)	C2—C3—H3	126.0
C1—N2—H2A	125.8	C5—O4—H4	109.5
N1—N2—H2A	125.8	O3—C4—O1	127.0 (5)
N2—C1—C2	109.1 (5)	O3—C4—C5	117.3 (4)
N2—C1—H1	125.4	O1—C4—C5	115.7 (4)
C2—C1—H1	125.4	O2—C5—O4	122.4 (5)
C1—C2—C3	105.2 (5)	O2—C5—C4	122.1 (5)
C1—C2—H2	127.4	O4—C5—C4	115.4 (4)
C3—N1—N2—C1	0.1 (6)	O3—C4—C5—O2	−178.2 (5)
N1—N2—C1—C2	0.0 (6)	O1—C4—C5—O2	1.9 (8)
N2—C1—C2—C3	0.0 (6)	O3—C4—C5—O4	1.0 (7)
N2—N1—C3—C2	−0.1 (6)	O1—C4—C5—O4	−178.9 (4)
C1—C2—C3—N1	0.1 (6)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1i	0.86	1.86	2.709 (5)	170
N2—H2A···O1ii	0.86	1.92	2.715 (5)	153
O4—H4···O3iii	0.82	1.95	2.679 (5)	147

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1i	0.86	1.86	2.709 (5)	170
N2—H2A⋯O1ii	0.86	1.92	2.715 (5)	153
O4—H4⋯O3iii	0.82	1.95	2.679 (5)	147

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