Hydrogen-bonded complexes of 2-pyridone with centrosymmetric and non-centrosymmetric dicarboxylic acids

2-Pyridone (2-oxo­pyrimidine) forms hydrogen-bonded com­plexes with di­carboxyl­ic acids, the molar ratio of 2-pyridone/di­carboxyl­ic acid being 2:1 for the complexes with oxalic acid (ethanedioic acid), 2C₅H₅NO·C₂H₂O₄, (I), and trans-β-hydro­muconic acid (trans-hex-3-enedioic acid), 2C₅H₅NO·C₆H₈O₄, (II), and 1:1 for the complexes with trans-glutaconic acid (trans-pent-2-enedioic acid), C₅H₅NO·C₅H₆O₄, (III), and L-­tartaric acid (L-2,3-di­hydroxy­butane­dioic acid), C₅H₅NO·C₄H₆O₆·H₂O, (IV). Common features in the hydrogen-bonding patterns were found for the centrosymmetric and non-centrosymmetric acids, respectively. The 2-pyridone mol­ecule takes the lactam form in these crystals.

S1. Comment

2-Pyridone has been extensively studied because it exhibits lactam-lactim tautomerism, and the lactam group can be regarded as a model of cis-peptides and of the purine and pyrimidine bases of nucleic acids (Yang & Craven, 1998; Field & Hillier, 1987). The crystal structure of 2-pyridone has been determined from high-resolution X-ray data at 123 K, and the molecule is in the lactam form (Yang & Craven, 1998). In the present study, the title complexes, (I)-(IV), have been prepared under the expectation that the lactam group of 2-pyridone could be a building unit of a supramolecular synthon, and the patterns characteristic of the hydrogen-bonding and the geometries of the 2-pyridone moiety in the complexes have been elucidated. \sch

The hydrogen-bond patterns in (I) and (II) are shown in Figs. 1 and 2, respectively. In the crystals of (I) and (II), a molecule of the acid has a centre of symmetry. Two molecules of 2-pyridone related by an inversion centre form a dimer via an N—H···O hydrogen bond. The dimeric unit and the acid molecule are connected by an O—H···O hydrogen bond between the carboxyl group and the O atom of 2-pyridone, to form a chain (Figs. 1 and 2; Tables 2 and 4). In (I), the chains are arranged side by side to form a sheet on (111). The sheets are stacked along the c axis with short contacts O3···C7ⁱⁱ 3.302 (2) and O3···C7ⁱⁱⁱ 3.307 (2) Å [symmetry codes: (ii) 1 - x, - y, - z - 1; (iii) x, y, z - 1]. In the chain of (II), a C—H···O interaction is observed (Table 4). The chains are arranged around the twofold screw axis with normal van der Waals contacts and no sheet structure is formed. In spite of difference in the packing mode of the chains in (I) and (II), the patterns of the hydrogen bonds in the chains show a common feature in these crystals. Thus, the hydrogen-bond scheme, (1), as found in (I) and (II), can be recognized as the supramolecular synthon (Desiraju, 1995) possible in complexes of 2-pyridone/centrosymmetric dicarboxylic acid in the ratio 2:1.

The molecules of the acids in (III) and (IV) have no centre of symmetry (Figs. 3 and 4). In both crystals, one carboxyl group forms an O—H···O and an N—H···O hydrogen bond with a 2-pyridone molecule (Tables 6 and 8). The O2—H10···O1 hydrogen bond in (IV) is short, the O2—H10 bond length being elongated, as found for a short noncentrosymmetric O—H···O hydrogen bond in ammonium hydrogen tartronate [O—H 1.18 (3) and O···O 2.443 (2) Å; Taka et al., 1998]. It could not be confirmed whether atom H10 is disordered, because the difference Fourier map drawn by H10 showed a single peak. In (III), the other carboxyl group forms an O—H···O hydrogen bond with a 2-pyridone molecule at (x - 1, 1/2 - y, 1/2 + z) to form a zigzag chain, and the chains form a sheet on (102) with C—H···O interactions (Fig. 5 and Table 6). The other carboxyl group in (IV) forms a hydrogen bond with a water molecule. The water molecule forms bifurcated hydrogen bonds with the acid molecules related by a translation along a and by the twofold screw axes along the a axis, forming a sheet developed parallel to (040) (Fig. 6 and Table 8). Between the sheets related by the twofold screw axes along the c axis, there are a C—H···O interaction and some short contacts between overlapped molecules of 2-pyridone: C9—H7 0.976 (12), H7···O1^v 2.563 (13) and C9···O1^v 3.255 (2) Å, and C9—H7···O1^v 127.9 (10)°; O3···C4^vi 3.186 (3), O1···C6^vii 3.373 (3), N1···C6^vii 3.280 (3) and C2···C6^vii 3.302 Å [symmetry codes: (v) 1/2 - x, 1 - y, z + 1/2; (vi) 3/2 - x, 1 - y, z - 1/2; (vii) 3/2 - x, 1 - y, 1/2 + z]. Because the hydrogen-bond scheme, (2), is found in both (III) and (IV), it can be recognized as the supramolecular synthon possible in complexes of 2-pyridone/noncentrosymmetric dicarboxylic acid in the ratio 1:1.

The geometries of the 2-pyridone moieties observed in compounds (I)-(IV) (Tables 1, 3, 5 and 7) show a common feature characteristic of the lactam form, as found in the crystal of 2-pyridone (Yang & Craven, 1998). The C—C distance [1.544 (2) Å] of oxalic acid in (I) is rather long for the Csp²—Csp² bond, as observed in dimorphs of oxalic acid [1.537 (1) Å; Derissen & Smit, 1974], and close to that determined for oxalic acid dihydrate at 15 K [1.5423 (5) Å; Zobel et al., 1992].

Related literature

For related literature, see: Derissen & Smit (1974); Desiraju (1995); Field & Hillier (1987); Taka et al. (1998); Yang & Craven (1998); Zobel et al. (1992).

S2. Experimental

Crystals of the four compounds were grown by slow evaporation from ethanol solutions of 2-pyridone and the respective dicarboxylic acid, with molar ratios of 1:1. Commercially available L-tartaric acid (Aldrich) was used for the preparation of (IV).

S3. Refinement

All H atoms were located from difference Fourier maps and refined isotropically. The ranges of the U_iso values for the H atoms were 0.051 (3)–0.084 (4) Ų for (I), 0.054 (3)–0.085 (4) Ų for (II), 0.055 (5)–0.154 (10) Ų for (III) and 0.015 (3)–0.146 (10) Ų for (IV). The values larger than 0.1 Ų were observed for H10 and H11 in (III), and H9, H10 and H12 in (IV). The least-squares refinement of (IV) was carried out by assuming the chirality of L-tartaric acid and removing redundant diffraction data. The calculations were performed at the Centre of Instrumental Analysis, Okayama University.

Computing details

For all compounds, 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, 1999); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: TEXSAN for Windows; molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: TEXSAN for Windows.

Figures

	Fig. 1. The molecular view of (I) showing the hydrogen-bonding pattern and the atomic numbering scheme for the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
	Fig. 2. The molecular view of (II) showing the hydrogen-bonding pattern and the atomic numbering scheme for the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
	Fig. 3. The molecular view of (III) showing the hydrogen-bonding pattern and the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
	Fig. 4. The molecular view of (IV) showing the hydrogen-bonding pattern and the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
	Fig. 5. The molecular arrangement in (201) of (III), viewed down the c axis. The a axis points towards the right and the b axis points upwards. Hydrogen bonds are shown by dashed lines. Symmetry codes: (i) x - 1, 1/2 - y, 1/2 + z; (ii) 1 - x, 1/2 + y, 1/2 - z; (iii) - x, 1 - y, 1 - z; (iv) 1 + x, 1/2 - y, z - 1/2; (v) 1 - x, y - 1/2, 1/2 - z.
	Fig. 6. A view down the c axis showing the formation of a double layer in (IV) through the hydrogen bonds involving water molecules. The a axis points towards the right and the b axis points upwards. Hydrogen bonds are shown by dashed lines. Symmetry codes: (i) x - 1, y, z; (iii) x - 1/2, 3/2 - y, 1 - z; (iv) 1/2 + x, 3/2 - y, 1 - z.

(I)

Crystal data

2C5H5NO·C2H2O4	Z = 1
Mr = 280.24	F(000) = 146
Triclinic, P1	Dx = 1.493 Mg m^−3
a = 9.162 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.898 (3) Å	Cell parameters from 18 reflections
c = 3.7672 (17) Å	θ = 9.4–11.5°
α = 98.86 (4)°	µ = 0.12 mm^−1
β = 97.66 (3)°	T = 298 K
γ = 109.61 (3)°	Prismatic, colourless
V = 311.6 (2) Å^3	0.50 × 0.38 × 0.35 mm

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.006
Radiation source: Rigaku rotating anode	θmax = 27.5°, θmin = 2.2°
Graphite monochromator	h = −11→11
ω/2θ scans	k = −12→12
1645 measured reflections	l = 0→4
1428 independent reflections	3 standard reflections every 97 reflections
1336 reflections with I > 0.1σ(I)	intensity decay: <0.9%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.059	All H-atom parameters refined
wR(F^2) = 0.098	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + 0.00031|Fo|^2]
S = 1.96	(Δ/σ)max = 0.001
1336 reflections	Δρmax = 0.24 e Å^−3
115 parameters	Δρmin = −0.22 e Å^−3

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

	x	y	z	Uiso*/Ueq
O1	0.80311 (7)	0.41104 (7)	0.0347 (2)	0.04484 (18)
O2	0.56467 (8)	0.19067 (7)	0.0910 (2)	0.0542 (2)
O3	0.67367 (8)	0.04132 (7)	−0.1697 (2)	0.0561 (2)
N1	0.95991 (8)	0.64707 (8)	0.2854 (2)	0.03573 (19)
C2	0.81684 (9)	0.53621 (9)	0.2102 (2)	0.0324 (2)
C3	0.69251 (10)	0.57249 (10)	0.3352 (3)	0.0394 (2)
C4	0.71801 (12)	0.71081 (11)	0.5140 (3)	0.0428 (3)
C5	0.86907 (12)	0.82065 (10)	0.5837 (3)	0.0443 (3)
C6	0.98733 (11)	0.78527 (10)	0.4669 (3)	0.0427 (3)
C7	0.57155 (9)	0.06303 (9)	−0.0288 (3)	0.0370 (2)
H1	1.0371 (15)	0.6232 (12)	0.194 (3)	0.053 (3)*
H2	0.5883 (14)	0.4935 (12)	0.284 (3)	0.051 (3)*
H3	0.6346 (15)	0.7365 (13)	0.596 (3)	0.060 (3)*
H4	0.8863 (13)	0.9167 (13)	0.716 (3)	0.057 (3)*
H5	1.0942 (15)	0.8534 (12)	0.501 (3)	0.059 (3)*
H6	0.6554 (18)	0.2687 (17)	0.058 (4)	0.084 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0383 (3)	0.0275 (3)	0.0682 (4)	0.0092 (3)	0.0244 (3)	0.0033 (3)
O2	0.0458 (4)	0.0289 (3)	0.0893 (6)	0.0096 (3)	0.0380 (4)	0.0050 (3)
O3	0.0412 (4)	0.0401 (4)	0.0894 (6)	0.0118 (3)	0.0376 (4)	0.0060 (4)
N1	0.0302 (4)	0.0318 (4)	0.0476 (4)	0.0124 (3)	0.0140 (3)	0.0077 (3)
C2	0.0312 (4)	0.0304 (4)	0.0389 (5)	0.0120 (3)	0.0129 (3)	0.0098 (3)
C3	0.0320 (4)	0.0397 (5)	0.0499 (5)	0.0129 (4)	0.0184 (4)	0.0104 (4)
C4	0.0463 (5)	0.0464 (5)	0.0479 (5)	0.0260 (4)	0.0227 (4)	0.0130 (4)
C5	0.0545 (6)	0.0334 (5)	0.0480 (5)	0.0187 (4)	0.0174 (4)	0.0045 (4)
C6	0.0382 (5)	0.0330 (5)	0.0534 (6)	0.0089 (4)	0.0121 (4)	0.0062 (4)
C7	0.0309 (4)	0.0316 (4)	0.0469 (5)	0.0095 (3)	0.0143 (4)	0.0026 (4)

Geometric parameters (Å, º)

O1—C2	1.2683 (15)	C4—H3	0.955 (18)
N1—C2	1.3573 (16)	C5—C6	1.3507 (19)
N1—C6	1.3554 (17)	C5—H4	0.953 (16)
N1—H1	0.908 (19)	C6—H5	0.963 (17)
C2—C3	1.4191 (16)	O2—C7	1.2996 (15)
C3—C4	1.3573 (19)	O2—H6	0.96 (2)
C3—H2	0.981 (16)	O3—C7	1.1983 (15)
C4—C5	1.404 (2)	C7—C7^i	1.544 (2)
O3···C7^ii	3.302 (2)	O3···C5^iv	3.3588 (19)
O3···C7^iii	3.307 (2)	O3···H4^iv	2.679 (17)
C2—N1—C6	123.88 (11)	C5—C4—H3	118.1 (11)
C2—N1—H1	114.7 (10)	C4—C5—C6	118.39 (12)
C6—N1—H1	121.3 (10)	C4—C5—H4	119.7 (10)
O1—C2—N1	118.99 (10)	C6—C5—H4	121.8 (10)
O1—C2—C3	125.19 (11)	N1—C6—C5	120.53 (12)
N1—C2—C3	115.81 (11)	N1—C6—H5	115.3 (10)
C2—C3—C4	120.89 (12)	C5—C6—H5	124.1 (10)
C2—C3—H2	116.9 (9)	C7—O2—H6	111.1 (12)
C4—C3—H2	122.2 (9)	O2—C7—O3	125.93 (11)
C3—C4—C5	120.49 (12)	O2—C7—C7^i	111.68 (12)
C3—C4—H3	121.4 (11)	O3—C7—C7^i	122.39 (14)
O1—C2—N1—C6	179.19 (12)	C2—C3—C4—C5	−0.9 (2)
O1—C2—C3—C4	−178.48 (12)	C3—C2—N1—C6	−0.15 (18)
N1—C2—C3—C4	0.81 (19)	C3—C4—C5—C6	0.3 (2)
N1—C6—C5—C4	0.3 (2)	O2—C7—C7^i—O3^i	−0.4 (3)
C2—N1—C6—C5	−0.4 (2)

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

(II)

Crystal data

2C5H5NO·C6H8O4	F(000) = 352
Mr = 334.33	Dx = 1.330 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.824 (3) Å	Cell parameters from 25 reflections
b = 5.5720 (17) Å	θ = 10–11°
c = 15.556 (5) Å	µ = 0.10 mm^−1
β = 101.31 (3)°	T = 298 K
V = 835.0 (5) Å^3	Prismatic, colourless
Z = 2	0.43 × 0.35 × 0.20 mm

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.009
Radiation source: Rigaku rotating anode	θmax = 30.0°, θmin = 2.1°
Graphite monochromator	h = 0→13
ω/2θ scans	k = 0→7
2802 measured reflections	l = −21→21
2429 independent reflections	3 standard reflections every 97 reflections
2187 reflections with I > 0.1σ(I)	intensity decay: <0.1%

Refinement

Refinement on F^2	0 constraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.059	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + 0.00022|Fo|^2]
wR(F^2) = 0.102	(Δ/σ)max = 0.010
S = 1.89	Δρmax = 0.26 e Å^−3
2187 reflections	Δρmin = −0.30 e Å^−3
146 parameters	Extinction correction: Zachariasen (1967), equ(3), Acta Cryst. (1968). A24, p213.
0 restraints	Extinction coefficient: 1.6 (4) × 10^-6

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

	x	y	z	Uiso*/Ueq
O1	0.42044 (7)	0.13718 (12)	0.07540 (4)	0.05736 (19)
O2	0.26139 (7)	0.46278 (13)	0.12498 (4)	0.0566 (2)
O3	0.21963 (9)	0.56938 (15)	−0.01457 (4)	0.0768 (3)
N1	0.55942 (7)	−0.18999 (13)	0.10368 (5)	0.04455 (19)
C2	0.47795 (9)	−0.01743 (15)	0.13013 (5)	0.0422 (2)
C3	0.46415 (10)	−0.02961 (17)	0.21914 (5)	0.0508 (3)
C4	0.52890 (11)	−0.20255 (18)	0.27268 (6)	0.0554 (3)
C5	0.61049 (11)	−0.37510 (19)	0.24190 (6)	0.0560 (3)
C6	0.62347 (10)	−0.36531 (17)	0.15700 (6)	0.0509 (3)
C7	0.20316 (9)	0.59895 (16)	0.05882 (5)	0.0447 (2)
C8	0.11163 (10)	0.79070 (17)	0.08523 (6)	0.0470 (2)
C9	0.06462 (9)	0.97199 (16)	0.01504 (5)	0.0427 (2)
H1	0.5684 (9)	−0.1862 (17)	0.0456 (6)	0.054 (3)*
H2	0.4087 (10)	0.0918 (19)	0.2374 (6)	0.060 (3)*
H3	0.5158 (11)	−0.207 (2)	0.3317 (7)	0.070 (3)*
H4	0.6525 (12)	−0.502 (2)	0.2755 (7)	0.077 (4)*
H5	0.6743 (10)	−0.4714 (17)	0.1293 (6)	0.054 (3)*
H6	0.0333 (11)	0.7090 (19)	0.0999 (6)	0.061 (3)*
H7	0.1626 (10)	0.867 (2)	0.1389 (7)	0.064 (3)*
H8	0.1336 (10)	1.0497 (18)	−0.0066 (6)	0.054 (3)*
H9	0.3205 (13)	0.357 (2)	0.1031 (8)	0.085 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0710 (4)	0.0600 (4)	0.0411 (3)	0.0280 (3)	0.0109 (3)	0.0047 (3)
O2	0.0685 (4)	0.0580 (4)	0.0432 (3)	0.0257 (3)	0.0108 (3)	0.0052 (3)
O3	0.1102 (6)	0.0810 (5)	0.0445 (4)	0.0425 (5)	0.0282 (4)	0.0073 (4)
N1	0.0496 (4)	0.0496 (4)	0.0353 (3)	0.0100 (3)	0.0105 (3)	0.0005 (3)
C2	0.0459 (4)	0.0442 (5)	0.0356 (4)	0.0061 (4)	0.0057 (3)	−0.0026 (3)
C3	0.0629 (6)	0.0535 (5)	0.0371 (4)	0.0119 (5)	0.0127 (4)	−0.0048 (4)
C4	0.0716 (6)	0.0602 (6)	0.0350 (4)	0.0055 (5)	0.0123 (4)	0.0020 (4)
C5	0.0677 (6)	0.0526 (5)	0.0464 (5)	0.0119 (5)	0.0082 (4)	0.0101 (4)
C6	0.0559 (5)	0.0490 (5)	0.0481 (5)	0.0134 (4)	0.0110 (4)	0.0001 (4)
C7	0.0493 (5)	0.0441 (5)	0.0406 (4)	0.0064 (4)	0.0087 (3)	−0.0001 (4)
C8	0.0516 (5)	0.0503 (5)	0.0400 (4)	0.0123 (4)	0.0110 (4)	0.0034 (4)
C9	0.0471 (4)	0.0409 (4)	0.0419 (4)	0.0048 (4)	0.0127 (4)	0.0024 (4)

Geometric parameters (Å, º)

O1—C2	1.2639 (13)	C6—H5	0.933 (14)
N1—C2	1.3652 (15)	O2—C7	1.3158 (14)
N1—C6	1.3540 (16)	O2—H9	0.937 (19)
N1—H1	0.925 (13)	O3—C7	1.1954 (14)
C2—C3	1.4191 (16)	C7—C8	1.5046 (17)
C3—C4	1.3488 (18)	C8—C9	1.4927 (16)
C3—H2	0.947 (14)	C8—H6	0.959 (14)
C4—C5	1.395 (2)	C8—H7	0.982 (15)
C4—H3	0.952 (14)	C9—C9^i	1.302 (2)
C5—C6	1.3526 (19)	C9—H8	0.921 (14)
C5—H4	0.925 (15)
C6···O3^ii	3.1492 (19)	H5···O3^ii	2.301 (14)
C7—O2—H9	106.5 (10)	N1—C6—C5	120.38 (12)
C2—N1—C6	123.57 (10)	N1—C6—H5	113.6 (8)
C2—N1—H1	116.9 (8)	C5—C6—H5	126.0 (8)
C6—N1—H1	119.5 (8)	O2—C7—O3	123.23 (11)
O1—C2—N1	119.22 (10)	O2—C7—C8	112.79 (10)
O1—C2—C3	125.04 (10)	O3—C7—C8	123.97 (11)
N1—C2—C3	115.74 (10)	C7—C8—C9	113.36 (10)
C2—C3—C4	120.86 (11)	C7—C8—H6	106.2 (9)
C2—C3—H2	115.4 (8)	C7—C8—H7	107.9 (8)
C4—C3—H2	123.7 (8)	C9—C8—H6	110.3 (8)
C3—C4—C5	120.90 (11)	C9—C8—H7	111.2 (9)
C3—C4—H3	118.6 (9)	H6—C8—H7	107.7 (11)
C5—C4—H3	120.5 (9)	C8—C9—C9	124.41 (15)
C4—C5—C6	118.54 (12)	C8—C9—H8	116.2 (8)
C4—C5—H4	123.6 (10)	C9—C9^i—H8^i	119.4 (8)
C6—C5—H4	117.8 (10)
O1—C2—N1—C6	−178.90 (12)	C3—C2—N1—C6	0.56 (17)
O1—C2—C3—C4	179.54 (13)	C3—C4—C5—C6	0.0 (2)
N1—C2—C3—C4	0.12 (18)	O2—C7—C8—C9	170.00 (11)
N1—C6—C5—C4	0.6 (2)	O3—C7—C8—C9	−11.4 (2)
C2—N1—C6—C5	−1.0 (2)	C7—C8—C9—C9^i	125.59 (17)
C2—C3—C4—C5	−0.4 (2)

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

(III)

Crystal data

C5H5NO·C5H6O4	F(000) = 472
Mr = 225.20	Dx = 1.382 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.889 (3) Å	Cell parameters from 25 reflections
b = 16.839 (10) Å	θ = 10.8–11.4°
c = 8.288 (2) Å	µ = 0.11 mm^−1
β = 100.49 (3)°	T = 298 K
V = 1082.5 (7) Å^3	Prismatic, colourless
Z = 4	0.43 × 0.40 × 0.27 mm

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.016
Radiation source: Rigaku rotating anode	θmax = 26.0°, θmin = 2.4°
Graphite monochromator	h = 0→9
ω/2θ scans	k = 0→20
2298 measured reflections	l = −10→10
2128 independent reflections	3 standard reflections every 97 reflections
1848 reflections with I > 0.1σ(I)	intensity decay: <0.3%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.079	All H-atom parameters refined
wR(F^2) = 0.088	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + 0.00022|Fo|^2]
S = 1.47	(Δ/σ)max = 0.010
1848 reflections	Δρmax = 0.19 e Å^−3
189 parameters	Δρmin = −0.25 e Å^−3

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

	x	y	z	Uiso*/Ueq
O1	0.58952 (13)	0.41995 (6)	0.25918 (14)	0.0590 (4)
O2	0.32107 (16)	0.36545 (7)	0.37827 (16)	0.0671 (4)
O3	0.21697 (15)	0.48751 (7)	0.33856 (17)	0.0821 (5)
O4	−0.29487 (14)	0.21882 (7)	0.69388 (15)	0.0623 (4)
O5	−0.09776 (14)	0.17391 (6)	0.55638 (15)	0.0676 (4)
N1	0.50970 (17)	0.54898 (8)	0.23311 (17)	0.0530 (4)
C2	0.61778 (18)	0.48915 (9)	0.20861 (18)	0.0466 (5)
C3	0.7527 (2)	0.50969 (11)	0.1264 (2)	0.0551 (5)
C4	0.7700 (2)	0.58583 (12)	0.0771 (2)	0.0641 (6)
C5	0.6560 (2)	0.64483 (12)	0.1079 (3)	0.0681 (7)
C6	0.5276 (2)	0.62513 (10)	0.1852 (2)	0.0625 (6)
C7	0.20371 (19)	0.42006 (10)	0.3849 (2)	0.0532 (5)
C8	0.0546 (2)	0.39462 (11)	0.4550 (2)	0.0574 (6)
C9	0.0403 (2)	0.32930 (11)	0.5340 (2)	0.0538 (5)
C10	−0.1076 (3)	0.31216 (11)	0.6188 (3)	0.0611 (6)
C11	−0.16296 (19)	0.22764 (9)	0.61704 (19)	0.0474 (5)
H1	0.409 (2)	0.5304 (10)	0.285 (2)	0.089 (6)*
H2	0.8302 (19)	0.4711 (9)	0.1102 (18)	0.055 (5)*
H3	0.869 (2)	0.5988 (10)	0.028 (2)	0.085 (6)*
H4	0.674 (2)	0.6959 (12)	0.078 (2)	0.089 (7)*
H5	0.441 (2)	0.6641 (11)	0.215 (2)	0.092 (6)*
H6	−0.030 (2)	0.4344 (10)	0.447 (2)	0.084 (6)*
H7	0.129 (2)	0.2915 (10)	0.5470 (19)	0.064 (5)*
H8	−0.198 (2)	0.3466 (11)	0.582 (2)	0.079 (6)*
H9	−0.071 (2)	0.3287 (10)	0.739 (2)	0.092 (6)*
H10	0.406 (3)	0.3904 (13)	0.341 (3)	0.116 (8)*
H11	−0.311 (3)	0.1652 (16)	0.709 (3)	0.154 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0565 (7)	0.0403 (6)	0.0893 (9)	0.0025 (5)	0.0378 (6)	0.0005 (6)
O2	0.0631 (8)	0.0507 (8)	0.0988 (10)	0.0032 (6)	0.0449 (8)	0.0089 (6)
O3	0.0765 (9)	0.0530 (8)	0.1337 (12)	0.0071 (7)	0.0637 (9)	0.0200 (8)
O4	0.0589 (7)	0.0448 (7)	0.0947 (9)	−0.0043 (6)	0.0443 (7)	−0.0040 (6)
O5	0.0773 (8)	0.0478 (7)	0.0903 (9)	0.0038 (6)	0.0490 (7)	−0.0040 (6)
N1	0.0495 (8)	0.0446 (8)	0.0701 (9)	0.0021 (7)	0.0246 (7)	0.0019 (7)
C2	0.0432 (9)	0.0442 (9)	0.0545 (10)	−0.0018 (7)	0.0150 (8)	−0.0065 (8)
C3	0.0455 (10)	0.0564 (11)	0.0688 (12)	−0.0037 (9)	0.0244 (9)	−0.0081 (9)
C4	0.0565 (11)	0.0715 (13)	0.0688 (13)	−0.0197 (10)	0.0234 (10)	0.0004 (10)
C5	0.0714 (13)	0.0525 (12)	0.0821 (14)	−0.0101 (10)	0.0184 (11)	0.0076 (10)
C6	0.0646 (11)	0.0474 (11)	0.0780 (13)	0.0023 (9)	0.0199 (10)	0.0048 (9)
C7	0.0518 (10)	0.0490 (10)	0.0654 (11)	0.0018 (8)	0.0283 (9)	0.0013 (9)
C8	0.0550 (10)	0.0525 (10)	0.0722 (12)	−0.0011 (9)	0.0316 (9)	0.0039 (9)
C9	0.0556 (10)	0.0478 (10)	0.0647 (12)	−0.0044 (9)	0.0285 (9)	−0.0050 (9)
C10	0.0681 (12)	0.0493 (11)	0.0767 (14)	−0.0123 (10)	0.0417 (11)	−0.0071 (10)
C11	0.0460 (9)	0.0471 (9)	0.0531 (10)	−0.0015 (7)	0.0200 (8)	0.0005 (8)

Geometric parameters (Å, º)

O1—C2	1.271 (2)	O2—H10	0.89 (3)
N1—C2	1.359 (2)	O3—C7	1.209 (2)
N1—C6	1.357 (3)	O4—C11	1.324 (2)
N1—H1	1.02 (2)	O4—H11	0.92 (3)
C2—C3	1.407 (2)	O5—C11	1.196 (2)
C3—C4	1.360 (3)	C7—C8	1.468 (3)
C3—H2	0.919 (18)	C8—C9	1.296 (3)
C4—C5	1.395 (3)	C8—H6	0.94 (2)
C4—H3	0.97 (2)	C9—C10	1.496 (3)
C5—C6	1.335 (3)	C9—H7	0.938 (17)
C5—H4	0.91 (2)	C10—C11	1.488 (3)
C6—H5	1.01 (2)	C10—H8	0.93 (2)
O2—C7	1.313 (2)	C10—H9	1.03 (2)
C4···O5^i	3.339 (3)	H5···O4^ii	2.47 (2)
H3···O5^i	2.41 (2)	C3···O5^iii	3.397 (3)
C6···O4^ii	3.457 (3)	H2···O5^iii	2.565 (15)
C2—N1—C6	123.72 (17)	C11—O4—H11	108.5 (19)
C2—N1—H1	113.2 (12)	O2—C7—O3	122.82 (16)
C6—N1—H1	123.0 (12)	O2—C7—C8	115.73 (19)
O1—C2—N1	118.53 (15)	O3—C7—C8	121.44 (18)
O1—C2—C3	125.31 (17)	C7—C8—C9	126.7 (2)
N1—C2—C3	116.13 (17)	C7—C8—H6	111.8 (13)
C2—C3—C4	120.25 (19)	C9—C8—H6	121.2 (13)
C2—C3—H2	118.6 (11)	C8—C9—C10	123.3 (2)
C4—C3—H2	121.1 (11)	C8—C9—H7	120.1 (12)
C3—C4—C5	120.8 (2)	C10—C9—H7	116.5 (12)
C3—C4—H3	118.1 (13)	C9—C10—C11	115.62 (17)
C5—C4—H3	120.8 (13)	C9—C10—H8	110.1 (13)
C4—C5—C6	118.9 (2)	C9—C10—H9	107.4 (12)
C4—C5—H4	118.9 (14)	C11—C10—H8	112.9 (14)
C6—C5—H4	122.2 (14)	C11—C10—H9	107.4 (12)
N1—C6—C5	120.2 (2)	H8—C10—H9	102.4 (18)
N1—C6—H5	115.6 (12)	O4—C11—O5	123.60 (17)
C5—C6—H5	124.2 (13)	O4—C11—C10	110.95 (16)
C7—O2—H10	105.2 (17)	O5—C11—C10	125.45 (16)
O1—C2—N1—C6	179.68 (19)	C3—C4—C5—C6	−0.8 (4)
O1—C2—C3—C4	179.7 (2)	O2—C7—C8—C9	12.1 (3)
N1—C2—C3—C4	0.3 (3)	O3—C7—C8—C9	−167.0 (2)
N1—C6—C5—C4	0.3 (4)	O4—C11—C10—C9	−179.7 (2)
C2—N1—C6—C5	0.6 (3)	O5—C11—C10—C9	1.1 (4)
C2—C3—C4—C5	0.5 (3)	C7—C8—C9—C10	172.5 (2)
C3—C2—N1—C6	−0.9 (3)	C8—C9—C10—C11	145.6 (2)

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

(IV)

Crystal data

C5H5NO·C4H6O6·H2O	Dx = 1.516 Mg m^−3
Mr = 263.20	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 25 reflections
a = 8.528 (5) Å	θ = 10.8–11.5°
b = 20.668 (8) Å	µ = 0.14 mm^−1
c = 6.5438 (15) Å	T = 295 K
V = 1153.4 (7) Å^3	Prismatic, colourless
Z = 4	0.53 × 0.28 × 0.20 mm
F(000) = 552

Data collection

Rigaku AFC-5R diffractometer	2064 reflections with I > 0.1σ(I)
Radiation source: Rigaku rotating anode	Rint = 0.011
Graphite monochromator	θmax = 32.0°, θmin = 2.0°
ω/2θ scans	h = 0→12
Absorption correction: ψ scans (North et al., 1968)	k = 0→30
Tmin = 0.952, Tmax = 0.999	l = −1→9
2660 measured reflections	3 standard reflections every 97 reflections
2303 independent reflections	intensity decay: <0.5%

Refinement

Refinement on F^2	0 constraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.044	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + 0.00001|Fo|^2]
wR(F^2) = 0.044	(Δ/σ)max = 0.010
S = 1.80	Δρmax = 0.32 e Å^−3
2064 reflections	Δρmin = −0.31 e Å^−3
216 parameters	Extinction correction: Zachariasen (1967), equ(3), Acta Cryst. (1968). A24, p213.
0 restraints	Extinction coefficient: 1.68 × 10 (12)^-6

Special details

Geometry. The O2—H10 length, 1.20 (2) Å, is elongated in the short O—H···O hydrogen bond.

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

	x	y	z	Uiso*/Ueq
O1	0.49399 (12)	0.43810 (5)	0.25423 (17)	0.0541 (3)
O2	0.31341 (10)	0.53184 (5)	0.21738 (18)	0.0558 (3)
O3	0.51062 (10)	0.60285 (4)	0.19044 (15)	0.0467 (3)
O4	0.31260 (12)	0.70141 (5)	0.13139 (18)	0.0496 (3)
O5	0.25390 (12)	0.66734 (5)	0.53540 (15)	0.0458 (3)
O6	−0.09014 (13)	0.66162 (5)	0.22679 (19)	0.0556 (4)
O7	−0.01411 (11)	0.73370 (4)	0.46179 (16)	0.0540 (3)
O8	−0.34509 (12)	0.73051 (6)	0.1702 (2)	0.0470 (3)
N1	0.72157 (13)	0.49451 (6)	0.2167 (2)	0.0423 (4)
C2	0.64150 (17)	0.43759 (7)	0.2387 (2)	0.0431 (4)
C3	0.73498 (19)	0.38140 (7)	0.2403 (3)	0.0488 (5)
C4	0.89252 (18)	0.38451 (8)	0.2219 (3)	0.0548 (6)
C5	0.96815 (19)	0.44382 (9)	0.2021 (3)	0.0518 (5)
C6	0.88088 (19)	0.49770 (8)	0.1992 (3)	0.0490 (5)
C7	0.37157 (17)	0.58980 (7)	0.1943 (2)	0.0409 (4)
C8	0.24346 (17)	0.64044 (6)	0.1745 (2)	0.0375 (4)
C9	0.15579 (16)	0.64452 (7)	0.3785 (2)	0.0369 (4)
C10	0.00891 (16)	0.68594 (7)	0.3606 (2)	0.0406 (4)
H1	0.6595 (14)	0.5334 (6)	0.211 (2)	0.059 (5)*
H2	0.6820 (14)	0.3442 (5)	0.2578 (19)	0.041 (4)*
H3	0.9538 (16)	0.3431 (6)	0.227 (2)	0.070 (5)*
H4	1.0811 (15)	0.4476 (6)	0.178 (2)	0.062 (5)*
H5	0.9227 (12)	0.5395 (5)	0.1839 (19)	0.033 (4)*
H6	0.1714 (12)	0.6266 (5)	0.0702 (17)	0.027 (4)*
H7	0.1185 (11)	0.6012 (4)	0.4129 (15)	0.015 (3)*
H8	0.2600 (17)	0.7179 (7)	0.045 (3)	0.077 (7)*
H9	0.318 (2)	0.7022 (8)	0.491 (3)	0.145 (9)*
H10	0.4094 (19)	0.4904 (8)	0.246 (3)	0.101 (6)*
H11	−0.1720 (17)	0.6843 (7)	0.219 (3)	0.073 (6)*
H12	−0.427 (2)	0.7064 (10)	0.156 (4)	0.146 (10)*
H13	−0.3645 (19)	0.7532 (7)	0.266 (2)	0.074 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0408 (6)	0.0429 (6)	0.0786 (8)	0.0001 (5)	−0.0053 (6)	−0.0040 (6)
O2	0.0380 (5)	0.0405 (5)	0.0889 (8)	−0.0019 (5)	0.0013 (6)	−0.0001 (6)
O3	0.0329 (5)	0.0459 (6)	0.0611 (7)	−0.0000 (5)	0.0045 (6)	−0.0007 (6)
O4	0.0455 (6)	0.0484 (6)	0.0549 (8)	−0.0049 (5)	−0.0052 (6)	0.0161 (6)
O5	0.0402 (6)	0.0524 (6)	0.0449 (6)	−0.0019 (6)	−0.0059 (6)	−0.0039 (6)
O6	0.0415 (6)	0.0569 (7)	0.0685 (8)	0.0114 (6)	−0.0137 (7)	−0.0156 (7)
O7	0.0478 (6)	0.0416 (6)	0.0726 (8)	0.0073 (5)	−0.0033 (6)	−0.0165 (6)
O8	0.0369 (6)	0.0577 (7)	0.0464 (7)	−0.0031 (6)	0.0040 (6)	−0.0055 (6)
N1	0.0451 (8)	0.0398 (7)	0.0419 (8)	0.0001 (6)	−0.0015 (7)	−0.0043 (7)
C2	0.0485 (9)	0.0408 (8)	0.0400 (9)	−0.0027 (8)	−0.0031 (8)	−0.0066 (8)
C3	0.0556 (10)	0.0349 (8)	0.0560 (11)	−0.0006 (8)	−0.0042 (10)	−0.0054 (8)
C4	0.0541 (10)	0.0549 (11)	0.0552 (12)	0.0102 (9)	−0.0008 (10)	−0.0073 (10)
C5	0.0432 (10)	0.0602 (11)	0.0521 (11)	0.0012 (9)	0.0038 (9)	−0.0028 (10)
C6	0.0542 (10)	0.0519 (10)	0.0408 (10)	−0.0121 (9)	0.0020 (9)	0.0009 (9)
C7	0.0425 (8)	0.0455 (9)	0.0347 (9)	0.0005 (7)	0.0022 (8)	−0.0010 (8)
C8	0.0349 (7)	0.0386 (8)	0.0391 (9)	−0.0038 (7)	−0.0040 (8)	0.0028 (7)
C9	0.0324 (8)	0.0320 (7)	0.0464 (10)	−0.0044 (7)	0.0008 (8)	0.0012 (7)
C10	0.0350 (8)	0.0398 (8)	0.0471 (10)	−0.0031 (7)	0.0038 (9)	0.0039 (7)

Geometric parameters (Å, º)

O1—C2	1.262 (2)	O4—C8	1.419 (2)
N1—C2	1.368 (2)	O4—H8	0.80 (2)
N1—C6	1.365 (3)	O5—C9	1.406 (2)
N1—H1	0.962 (16)	O5—H9	0.95 (2)
C2—C3	1.409 (3)	O6—C10	1.316 (2)
C3—C4	1.350 (3)	O6—H11	0.842 (19)
C3—H2	0.900 (15)	O7—C10	1.205 (2)
C4—C5	1.391 (3)	C7—C8	1.518 (3)
C4—H3	1.003 (17)	C8—C9	1.532 (3)
C5—C6	1.340 (3)	C8—H6	0.962 (15)
C5—H4	0.979 (16)	C9—C10	1.522 (3)
C6—H5	0.941 (14)	C9—H7	0.976 (12)
O2—C7	1.305 (2)	O8—H12	0.86 (3)
O2—H10	1.20 (2)	O8—H13	0.798 (19)
O3—C7	1.216 (2)
C9···O1^i	3.255 (2)	O1···C6^iii	3.373 (3)
H7···O1^i	2.563 (13)	N1···C6^iii	3.280 (3)
O3···C4^ii	3.186 (3)	C2···C6^iii	3.302 (3)
C2—N1—C6	123.18 (19)	C10—O6—H11	111.1 (14)
C2—N1—H1	116.6 (10)	O2—C7—O3	125.19 (18)
C6—N1—H1	120.2 (10)	O2—C7—C8	111.66 (17)
O1—C2—N1	119.92 (18)	O3—C7—C8	123.15 (17)
O1—C2—C3	124.78 (19)	O4—C8—C7	109.27 (16)
N1—C2—C3	115.30 (18)	O4—C8—C9	109.09 (15)
C2—C3—C4	121.5 (2)	O4—C8—H6	112.8 (9)
C2—C3—H2	115.0 (10)	C7—C8—C9	108.33 (16)
C4—C3—H2	123.5 (10)	C7—C8—H6	108.4 (9)
C3—C4—C5	120.8 (2)	C9—C8—H6	108.8 (9)
C3—C4—H3	118.4 (11)	O5—C9—C8	111.36 (15)
C5—C4—H3	120.9 (11)	O5—C9—C10	110.93 (16)
C4—C5—C6	118.4 (2)	O5—C9—H7	109.4 (8)
C4—C5—H4	122.7 (10)	C8—C9—C10	111.46 (16)
C6—C5—H4	118.6 (10)	C8—C9—H7	108.0 (8)
N1—C6—C5	120.8 (2)	C10—C9—H7	105.4 (8)
N1—C6—H5	115.5 (9)	O6—C10—O7	125.02 (18)
C5—C6—H5	123.7 (9)	O6—C10—C9	111.38 (17)
C7—O2—H10	114.5 (9)	O7—C10—C9	123.57 (19)
C8—O4—H8	106.7 (15)	H12—O8—H13	105 (2)
C9—O5—H9	112.1 (17)
O1—C2—N1—C6	180.0 (2)	O2—C7—C8—C9	66.5 (2)
O1—C2—C3—C4	179.6 (2)	O3—C7—C8—O4	5.8 (3)
N1—C2—C3—C4	0.2 (4)	O3—C7—C8—C9	−112.9 (2)
N1—C6—C5—C4	0.5 (4)	O4—C8—C9—O5	−53.87 (19)
C2—N1—C6—C5	0.2 (4)	O4—C8—C9—C10	70.59 (19)
C2—C3—C4—C5	0.5 (4)	O5—C9—C8—C7	65.0 (2)
C3—C2—N1—C6	−0.6 (3)	O5—C9—C10—O6	−174.34 (15)
C3—C4—C5—C6	−0.8 (4)	O5—C9—C10—O7	3.6 (3)
C7—C8—C9—C10	−170.56 (15)	O6—C10—C9—C8	61.0 (2)
O2—C7—C8—O4	−174.75 (17)	O7—C10—C9—C8	−121.1 (2)

Symmetry codes: (i) −x+1/2, −y+1, z+1/2; (ii) −x+3/2, −y+1, z−1/2; (iii) −x+3/2, −y+1, z+1/2.