3-Hydro­xy­pyridinium 2,5-di­hydroxy­benzoate

3-Hydro­xy­pyridine forms the title salt, C₅H₆NO⁺·C₇H₅O₄^-, with 2,5-di­hydroxy­benzoic acid. Hydro­gen bonds in the crystal link the cation and the anion to form a hydrogen-bonded ribbon.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.056
• wR factor = 0.179
• Data-to-parameter ratio = 15.6

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S1. Comment

The title compound, (I), was investigated as part of a study on D—H···A hydrogen bonding (D = N, O or C; A = N or O) in carboxylic acid and pyridine systems (Kashino et al., 2001; Ishida et al., 2001, 2002). 2,5-Dihydroxybenzoic acid is of potential interest in crystal engineering to form specific two- or three-dimensional aggregates with organic bases because the carboxyl and two hydroxyl groups of the acid may act as hydrogen-bond donors, as well as acceptors. The crystal structure of 2,5-dihydroxybenzoic acid itself was determined by Haisa et al. (1982), who showed dimorphs of the compound grown by two different solvents. We have found only one example (Aakeröy et al., 1995) of a structure containing the 2,5-dihydroxybenzoic acid moiety in the Cambridge Structural Database (Version 5.24 of November 2002; Allen, 2002), but no crystal data for compounds composed of 2,5-dihydroxybenzoic acid and pyridine derivatives are recorded.

In the title crystal, the 3-hydroxypyridinium cation and the 2,5-dihydroxybenzoate anion are held together by an N—H···O hydrogen bond (Table 2), forming the C₅H₆NO⁺·C₇H₅O₄⁻ unit (Fig. 1). An intramolecular hydrogen bond, O4—H7···O3, is observed in the unit. The units are linked by O—H···O hydrogen bonds, viz. O1—H3···O2ⁱ between the cation and anion, and O5—H10···O4ⁱⁱ between the anions, to form a hydrogen-bonded ribbon running along the b axis [Fig. 2; symmetry codes: (i) x, 1 + y, z; (ii) x, y − 1, z]. The dihedral angle between the planes of benzene and pyridine rings is 3.96 (10)°. Furthermore, C—H···O hydrogen bonds (C2—H2···O2ⁱ and C6—H6···O1ⁱⁱ) are formed in the ribbon. These hydrogen bonds play an important role and form a flat plane of the molecular ribbon. A C—H···O hydrogen bond, C5—H5···O5ⁱⁱⁱ [symmetry code: (iii) 1 + x, 1/2 − y, 1/2 + z], connects the ribbons to form a two-dimensional hydrogen-bonded network. These planes are stacked along the [102] direction by a π–π-stacking interaction between the pyridine and benzene rings. This interplanar separation and the centroid offset are 3.370 (19) and 2.11 (2) Å, respectively.

S2. Experimental

The crystals were grown by slow evaporation from an ethanol solution of 3-hydroxypyridine and 2,5-dihydroxybenzoic acid, with a molar ratio of 1:1.

S3. Refinement

All H atoms were located from difference Fourier maps and refined isotropically. Refined distances: C—H = 0.91 (3)–1.00 (2) Å, N—H = 0.99 (3) Å and O—H = 0.87 (4)–0.92 (3) Å.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1990); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1997-1999); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: TEXSAN for Windows; software used to prepare material for publication: TEXSAN for Windows.

Figures

	Fig. 1. ORTEP-3 (Farrugia, 1997) drawing with the atomic numbering of the asymmetric unit of (I). Displacement ellipsoids of non-H atoms are drawn at the 50% probability level. N—H···O and O—H···O hydrogen bonds are indicated by dashed lines.
	Fig. 2. Packing diagram of the molecular ribbons formed via N—H···O, O—H···O and C—H···O hydrogen bonds. The symmetry codes are as in Table 2.

(I)

Crystal data

C5H6NO^+·C7H5O4^−	F(000) = 520
Mr = 249.22	Dx = 1.479 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.659 (2) Å	θ = 11.3–11.5°
b = 7.1731 (17) Å	µ = 0.12 mm^−1
c = 20.468 (4) Å	T = 298 K
β = 95.454 (18)°	Plate, colorless
V = 1119.4 (5) Å^3	0.50 × 0.27 × 0.21 mm
Z = 4

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.031
Radiation source: Rigaku rotating anode	θmax = 30.0°, θmin = 2.7°
Graphite monochromator	h = −1→10
ω–2θ scans	k = −1→10
4496 measured reflections	l = −28→28
3252 independent reflections	3 standard reflections every 97 reflections
1878 reflections with I > 2σ(I)	intensity decay: 2.3%

Refinement

Refinement on F^2	0 constraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.056	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + 0.00203|Fo|^2]
wR(F^2) = 0.179	(Δ/σ)max = 0.001
S = 1.10	Δρmax = 0.37 e Å^−3
3252 reflections	Δρmin = −0.36 e Å^−3
208 parameters	Extinction correction: Zachariasen (1967), equ(3) Acta Cryst.(1968) 24, p213.
0 restraints	Extinction coefficient: 1.7 (3)E-6

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.4951 (3)	1.1583 (2)	0.61801 (10)	0.0619 (5)
O2	0.2621 (2)	0.1928 (2)	0.52261 (8)	0.0585 (5)
O3	0.2599 (2)	0.4962 (2)	0.50114 (7)	0.0513 (5)
O4	0.0893 (2)	0.6228 (2)	0.39858 (9)	0.0546 (5)
O5	−0.1000 (2)	−0.0975 (2)	0.33037 (8)	0.0549 (5)
N1	0.4441 (2)	0.6629 (3)	0.60081 (9)	0.0387 (5)
C2	0.4276 (3)	0.8440 (3)	0.58707 (10)	0.0388 (5)
C3	0.5064 (3)	0.9755 (3)	0.62988 (10)	0.0404 (5)
C4	0.6014 (3)	0.9113 (3)	0.68671 (11)	0.0435 (6)
C5	0.6149 (3)	0.7233 (3)	0.69940 (11)	0.0443 (6)
C6	0.5358 (3)	0.5985 (3)	0.65547 (11)	0.0431 (6)
C7	0.0973 (2)	0.2951 (3)	0.42658 (9)	0.0322 (5)
C8	0.0433 (3)	0.4427 (3)	0.38454 (10)	0.0358 (5)
C9	−0.0555 (3)	0.4051 (3)	0.32527 (10)	0.0404 (5)
C10	−0.1008 (3)	0.2249 (3)	0.30804 (10)	0.0398 (5)
C11	−0.0497 (3)	0.0777 (3)	0.35006 (10)	0.0371 (5)
C12	0.0484 (3)	0.1147 (3)	0.40892 (10)	0.0354 (5)
C13	0.2143 (3)	0.3294 (3)	0.48844 (9)	0.0371 (5)
H1	0.381 (3)	0.577 (4)	0.5691 (13)	0.053 (7)*
H2	0.358 (3)	0.881 (3)	0.5457 (11)	0.039 (6)*
H3	0.412 (4)	1.184 (4)	0.5847 (15)	0.072 (8)*
H4	0.660 (3)	0.999 (4)	0.7144 (13)	0.054 (7)*
H5	0.685 (3)	0.676 (4)	0.7393 (13)	0.057 (7)*
H6	0.543 (3)	0.472 (4)	0.6596 (12)	0.055 (7)*
H7	0.152 (4)	0.619 (4)	0.4392 (15)	0.072 (8)*
H8	−0.094 (4)	0.505 (5)	0.2961 (14)	0.070 (8)*
H9	−0.173 (3)	0.198 (3)	0.2656 (11)	0.040 (6)*
H10	−0.044 (4)	−0.171 (4)	0.3587 (15)	0.067 (8)*
H11	0.085 (3)	0.017 (3)	0.4374 (11)	0.038 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0763 (12)	0.0317 (9)	0.0698 (12)	−0.0054 (8)	−0.0349 (10)	0.0013 (8)
O2	0.0811 (12)	0.0392 (9)	0.0483 (9)	−0.0009 (8)	−0.0300 (8)	0.0067 (7)
O3	0.0667 (11)	0.0344 (9)	0.0480 (9)	−0.0033 (7)	−0.0198 (8)	−0.0060 (7)
O4	0.0710 (11)	0.0253 (8)	0.0608 (11)	−0.0023 (7)	−0.0286 (9)	0.0020 (7)
O5	0.0788 (12)	0.0304 (8)	0.0492 (10)	−0.0051 (8)	−0.0267 (8)	−0.0025 (7)
N1	0.0436 (10)	0.0324 (9)	0.0381 (9)	−0.0006 (7)	−0.0064 (7)	−0.0054 (7)
C2	0.0443 (11)	0.0341 (11)	0.0353 (10)	−0.0007 (9)	−0.0106 (9)	−0.0010 (8)
C3	0.0417 (11)	0.0324 (10)	0.0444 (11)	−0.0018 (8)	−0.0091 (9)	−0.0025 (9)
C4	0.0447 (12)	0.0414 (12)	0.0407 (11)	0.0002 (9)	−0.0153 (9)	−0.0084 (9)
C5	0.0475 (12)	0.0458 (12)	0.0368 (11)	0.0057 (10)	−0.0099 (9)	−0.0007 (9)
C6	0.0484 (12)	0.0338 (11)	0.0453 (12)	0.0042 (9)	−0.0050 (9)	−0.0003 (9)
C7	0.0376 (10)	0.0273 (9)	0.0305 (9)	0.0022 (7)	−0.0035 (8)	0.0000 (7)
C8	0.0396 (10)	0.0249 (10)	0.0407 (11)	0.0015 (8)	−0.0078 (8)	0.0004 (8)
C9	0.0455 (11)	0.0329 (10)	0.0398 (11)	0.0025 (9)	−0.0117 (9)	0.0066 (9)
C10	0.0423 (11)	0.0377 (11)	0.0365 (10)	−0.0004 (9)	−0.0116 (8)	0.0020 (9)
C11	0.0432 (11)	0.0282 (9)	0.0379 (10)	0.0011 (8)	−0.0061 (8)	−0.0028 (8)
C12	0.0424 (11)	0.0279 (10)	0.0341 (10)	0.0010 (8)	−0.0053 (8)	0.0028 (8)
C13	0.0437 (11)	0.0328 (10)	0.0326 (10)	0.0024 (8)	−0.0073 (8)	−0.0032 (8)

Geometric parameters (Å, º)

O1—C3	1.334 (3)	C4—H4	0.93 (3)
O1—H3	0.90 (3)	C5—C6	1.369 (3)
O2—C13	1.239 (3)	C5—H5	0.99 (3)
O3—C13	1.267 (3)	C6—H6	0.91 (3)
O4—C8	1.363 (3)	C7—C8	1.402 (3)
O4—H7	0.92 (3)	C7—C12	1.386 (3)
O5—C11	1.364 (3)	C7—C13	1.500 (3)
O5—H10	0.87 (4)	C8—C9	1.393 (3)
N1—C2	1.332 (3)	C9—C10	1.376 (3)
N1—C6	1.345 (3)	C9—H8	0.96 (3)
N1—H1	0.99 (3)	C10—C11	1.394 (3)
C2—C3	1.387 (3)	C10—H9	1.00 (2)
C2—H2	0.99 (2)	C11—C12	1.383 (3)
C3—C4	1.391 (3)	C12—H11	0.94 (2)
C4—C5	1.375 (3)
O2···C3^i	3.158 (3)	C2···C11^iii	3.325 (3)
O3···H2	2.98 (2)	C6···C8^ii	3.414 (3)
O3···H3^i	2.99 (3)	C8···H10^iv	2.89 (3)
O3···C2	3.246 (3)	C13···H3^i	2.59 (3)
N1···C13^ii	3.331 (3)	C13···H1	2.67 (3)
C3—O1—H3	111 (2)	C8—C7—C12	119.23 (18)
C8—O4—H7	105 (2)	C8—C7—C13	120.82 (18)
C11—O5—H10	105 (2)	C12—C7—C13	119.88 (18)
C2—N1—C6	122.8 (2)	O4—C8—C7	122.07 (18)
C2—N1—H1	115.8 (16)	O4—C8—C9	118.37 (18)
C6—N1—H1	121.3 (16)	C7—C8—C9	119.51 (18)
N1—C2—C3	120.22 (19)	C8—C9—C10	120.52 (19)
N1—C2—H2	118.4 (14)	C8—C9—H8	120.3 (18)
C3—C2—H2	121.4 (14)	C10—C9—H8	119.1 (18)
O1—C3—C2	122.5 (2)	C9—C10—C11	120.28 (19)
O1—C3—C4	119.8 (2)	C9—C10—H9	120.6 (14)
C2—C3—C4	117.7 (2)	C11—C10—H9	119.1 (14)
C3—C4—C5	120.5 (2)	O5—C11—C10	117.43 (19)
C3—C4—H4	117.8 (17)	O5—C11—C12	123.28 (19)
C5—C4—H4	121.6 (17)	C10—C11—C12	119.29 (19)
C4—C5—C6	119.8 (2)	C7—C12—C11	121.16 (18)
C4—C5—H5	121.1 (16)	C7—C12—H11	118.6 (15)
C6—C5—H5	119.1 (16)	C11—C12—H11	120.2 (15)
N1—C6—C5	119.0 (2)	O2—C13—O3	124.78 (19)
N1—C6—H6	116.1 (18)	O2—C13—C7	117.88 (18)
C5—C6—H6	124.9 (18)	O3—C13—C7	117.33 (18)
O1—C3—C2—N1	179.3 (2)	C2—N1—C6—C5	0.5 (4)
O1—C3—C4—C5	−179.6 (2)	C2—C3—C4—C5	−0.2 (4)
O2—C13—C7—C8	−177.8 (2)	C3—C2—N1—C6	−0.1 (4)
O2—C13—C7—C12	−0.9 (3)	C3—C4—C5—C6	0.6 (4)
O3—C13—C7—C8	0.7 (3)	C7—C8—C9—C10	0.4 (4)
O3—C13—C7—C12	177.6 (2)	C7—C12—C11—C10	−0.4 (4)
O4—C8—C7—C12	−178.9 (2)	C8—C7—C12—C11	1.3 (3)
O4—C8—C7—C13	−2.0 (3)	C8—C9—C10—C11	0.6 (4)
O4—C8—C9—C10	178.1 (2)	C9—C8—C7—C12	−1.3 (3)
O5—C11—C10—C9	179.5 (2)	C9—C8—C7—C13	175.7 (2)
O5—C11—C12—C7	179.5 (2)	C9—C10—C11—C12	−0.6 (4)
N1—C2—C3—C4	−0.1 (4)	C11—C12—C7—C13	−175.7 (2)
N1—C6—C5—C4	−0.8 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H3···O2^iv	0.90 (3)	1.63 (4)	2.530 (2)	171 (3)
O4—H7···O3	0.92 (3)	1.70 (3)	2.533 (2)	150 (3)
O5—H10···O4^i	0.87 (4)	1.93 (4)	2.773 (3)	163 (3)
N1—H1···O3	0.99 (3)	1.70 (3)	2.652 (2)	161 (2)
C2—H2···O2^iv	0.99 (2)	2.39 (2)	3.048 (3)	123 (2)
C5—H5···O5^v	0.99 (3)	2.43 (3)	3.414 (3)	169 (2)
C6—H6···O1^i	0.91 (3)	2.42 (3)	3.257 (3)	152 (2)

Symmetry codes: (i) x, y−1, z; (iv) x, y+1, z; (v) x+1, −y+1/2, z+1/2.