4-Carboxy-pyridazin-1-ium chloride.

The structure of the title compound, C(5)H(5)N(2)O(2) (+)·Cl(-), is composed of chloride anions and 4-carboxy-pyridazin-1-ium cations. Chloride anions bridge the cations via O-H⋯Cl and N-H⋯Cl hydrogen bonds to form ribbons. The latter, linked by van der Waals forces with lengths in the range 3.254 (2)-3.497 (2) Å, form coplanar layers. Very weak inter-actions operate also between adjacent layers, as indicated by their spacing of 3.339 (1) Å.

Related literature

For the crystal structure of pyridazine-3-carboxylic acid hydro­chloride, see: Gryz et al. (2003 ▶). For a report of mol­ecular layers in the structure of pyrazine-2-carboxylic acid, see: Takusagawa et al. (1974 ▶).

Experimental

Crystal data

C5H5N2O2 +·Cl−

M = 160.56

Monoclinic,

a = 6.8505 (14) Å

b = 6.5905 (13) Å

c = 14.561 (3) Å

β = 97.65 (3)°

V = 651.6 (2) Å3

Z = 4

Mo Kα radiation

μ = 0.52 mm−1

T = 293 (2) K

0.39 × 0.16 × 0.12 mm

Data collection

Kuma KM-4 four-circle diffractometer

Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008 ▶) T min = 0.942, T max = 0.952

2062 measured reflections

1917 independent reflections

1318 reflections with I > 2σ(I)

R int = 0.024

3 standard reflections every 200 reflections intensity decay: 1.1%

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.104

S = 1.03

1917 reflections

99 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.35 e Å−3

Δρmin = −0.21 e Å−3

Data collection: KM-4 Software (Kuma, 1996 ▶); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001 ▶); 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: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808022319/rk2101sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808022319/rk2101Isup2.hkl

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

C5H5N2O2+·Cl–	F000 = 328
Mr = 160.56	Dx = 1.637 Mg m−3
Monoclinic, P21/n	Mo Kα radiation λ = 0.71073 Å
a = 6.8505 (14) Å	Cell parameters from 6 reflections
b = 6.5905 (13) Å	θ = 6–15º
c = 14.561 (3) Å	µ = 0.52 mm−1
β = 97.65 (3)º	T = 293 (2) K
V = 651.6 (2) Å3	Block, colourless
Z = 4	0.39 × 0.16 × 0.12 mm

Kuma KM-4 four-circle diffractometer	Rint = 0.024
Radiation source: Fine–focus sealed tube	θmax = 30.1º
Monochromator: Graphite	θmin = 2.8º
T = 293(2) K	h = −9→0
Profile data from ω/2θ scans	k = 0→9
Absorption correction: Analytical(CrysAlis RED; Oxford Diffraction, 2008)	l = −20→20
Tmin = 0.942, Tmax = 0.952	3 standard reflections
2062 measured reflections	every 200 reflections
1917 independent reflections	intensity decay: 1.2%
1318 reflections with I > 2σ(I)

Refinement on F2	Secondary atom site location: Difmap
Least-squares matrix: Full	Hydrogen site location: Geom
R[F2 > 2σ(F2)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.104	w = 1/[σ2(Fo2) + (0.0577P)2 + 0.1527P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.001
1917 reflections	Δρmax = 0.36 e Å−3
99 parameters	Δρmin = −0.21 e Å−3
Primary atom site location: Direct	Extinction correction: None

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.

Refinement. Refinement of F^2^ against ALL reflections. The weighted R–factor wR and goodness of fit S are based on F^2^, conventional R–factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R–factors(gt) etc. and is not relevant to the choice of reflections for refinement. R–factors based on F^2^ 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
Cl1	0.61082 (6)	0.18289 (6)	0.39362 (3)	0.03696 (13)
O1	0.8041 (2)	0.6663 (2)	0.46266 (8)	0.0485 (3)
C3	0.8870 (3)	0.9337 (3)	0.61752 (11)	0.0382 (4)
H3	0.8395	0.9943	0.5613	0.046*
C4	0.8811 (2)	0.7225 (2)	0.62339 (10)	0.0296 (3)
O2	0.7273 (2)	0.4276 (2)	0.56133 (8)	0.0414 (3)
C7	0.7988 (2)	0.6028 (3)	0.53974 (10)	0.0330 (3)
C5	0.9550 (2)	0.6321 (2)	0.70515 (11)	0.0337 (3)
H5	0.9548	0.4918	0.7120	0.040*
N2	0.9559 (2)	1.0516 (2)	0.68707 (10)	0.0414 (3)
C6	1.0306 (3)	0.7589 (3)	0.77771 (11)	0.0376 (4)
H6	1.0841	0.7045	0.8345	0.045*
N1	1.0257 (2)	0.9555 (2)	0.76522 (10)	0.0368 (3)
H1	1.063 (3)	1.042 (4)	0.8143 (17)	0.063 (7)*
H2	0.675 (4)	0.358 (4)	0.5097 (19)	0.069 (8)*

	U11	U22	U33	U12	U13	U23
Cl1	0.0472 (2)	0.02641 (19)	0.0353 (2)	0.00189 (16)	−0.00212 (15)	−0.00355 (14)
O1	0.0698 (9)	0.0472 (8)	0.0264 (6)	0.0011 (7)	−0.0010 (5)	0.0038 (5)
C3	0.0507 (10)	0.0319 (8)	0.0309 (7)	0.0058 (7)	0.0017 (7)	0.0058 (6)
C4	0.0313 (7)	0.0310 (7)	0.0259 (6)	0.0027 (6)	0.0021 (5)	0.0015 (5)
O2	0.0567 (8)	0.0354 (6)	0.0303 (6)	−0.0046 (6)	−0.0010 (5)	−0.0028 (5)
C7	0.0371 (8)	0.0336 (8)	0.0267 (7)	0.0064 (6)	−0.0017 (6)	0.0005 (6)
C5	0.0406 (8)	0.0291 (7)	0.0295 (7)	0.0003 (6)	−0.0025 (6)	0.0030 (5)
N2	0.0554 (9)	0.0296 (7)	0.0386 (7)	0.0022 (7)	0.0041 (6)	0.0022 (5)
C6	0.0463 (9)	0.0349 (8)	0.0288 (7)	−0.0010 (7)	−0.0045 (6)	0.0028 (6)
N1	0.0443 (8)	0.0340 (7)	0.0315 (6)	−0.0034 (6)	0.0023 (5)	−0.0034 (5)

O1—C7	1.203 (2)	O2—H2	0.91 (3)
C3—N2	1.313 (2)	C5—C6	1.392 (2)
C3—C4	1.395 (2)	C5—H5	0.9300
C3—H3	0.9300	N2—N1	1.334 (2)
C4—C5	1.367 (2)	C6—N1	1.308 (2)
C4—C7	1.497 (2)	C6—H6	0.9300
O2—C7	1.309 (2)	N1—H1	0.92 (3)
N2—C3—C4	123.60 (15)	C4—C5—C6	117.17 (16)
N2—C3—H3	118.2	C4—C5—H5	121.4
C4—C3—H3	118.2	C6—C5—H5	121.4
C5—C4—C3	118.55 (15)	C3—N2—N1	115.32 (14)
C5—C4—C7	122.31 (15)	N1—C6—C5	119.27 (15)
C3—C4—C7	119.12 (14)	N1—C6—H6	120.4
C7—O2—H2	111.4 (17)	C5—C6—H6	120.4
O1—C7—O2	126.14 (16)	C6—N1—N2	126.06 (15)
O1—C7—C4	121.39 (16)	C6—N1—H1	120.2 (16)
O2—C7—C4	112.47 (13)	N2—N1—H1	113.5 (16)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···Cl1	0.91 (3)	2.05 (3)	2.9464 (14)	169 (2)
N1—H1···Cl1i	0.92 (3)	2.15 (3)	3.0373 (15)	160 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯Cl1	0.91 (3)	2.05 (3)	2.9464 (14)	169 (2)
N1—H1⋯Cl1i	0.92 (3)	2.15 (3)	3.0373 (15)	160 (2)

Symmetry code: (i) .