A simple compound with an ­unexpectedly complex structure: 4-pyridone 6/5-hydrate

The crystal structure of the title compound, C₅H₅NO·H₂O, contains five independent mol­ecules of pyridone and six independent water mol­ecules. The space group is P2₁, but four of the pyridones and four waters correspond closely to P2₁/n. The packing involves two layers; one consists of head-to-tail chains of pyridone mol­ecules 1–4 linked by N—H...O hydrogen bonds, and a second layer involves all the waters and the fifth pyridone. The layers are linked by hydrogen bonds from water to pyridone oxy­gen. The four water O atoms that accept only one classical hydrogen bond have their environment completed by C—H...O interactions.

S1. Comment

We are interested in the structures of pyridines substituted at the 4-position, and in particular in their secondary bonding interactions, which often lead to the formation of chains of molecules. We have recently published the structures of 4-iodopyridine (Ahrens & Jones, 1999), with N···I "halogen bonds" (Corradi et al., 2000); 4-halopyridinium halides (Jones et al., 1999), with halogen-halogen contacts and N—H···halide hydrogen bonds, and `4-mercaptopyridine' (pyridine-4-thione; Flakus et al., 2001), with N—H···S hydrogen bonds.

We have now turned our attention to "4-hydroxypyridine", which is known from spectroscopic studies to exist in the keto form as 4-pyridone; standard texts such as Meislich (1962) and Smith (1979) review the evidence. The structure of 2-pyridone has been determined several times, including low-temperature neutron diffraction and charge density studies; see Yang & Craven (1998) and references therein. For a brief discussion of tautomerism in hydroxypyridines, the reader is referred to Freytag & Jones (1999) and Wijaya et al. (1999).

Various derivatives, adducts and complexes of 4-pyridone have been investigated by X-ray methods, e.g. 2-amino-4-pyridones, used in some early crystal engineering studies (Toledo et al., 1994); the 1:1 adduct of 4-pyridone with 4-nitrophenol (Evans et al., 1998); the 2:1 adduct with nitric acid (Goodgame et al., 1993); and the complex ZnCl₂(C₅H₅NO)₂ (Masse & Le Fur, 1998). However, perhaps surprisingly, there appears to be no report of the structure of the parent compound itself. Well formed colourless crystals were obtained by evaporation from supposedly anhydrous acetone but the structure determination, reported here, shows these to be the hydrate 4-pyridone.6/5 H₂O, (I), presumably formed by the influence of adventitious water. \sch

The asymmetric unit contains five independent molecules of 4-pyridone (atoms are numbered with the first digit 1 for molecule 1, etc., and the second digit corresponding to the standard ring numbering) and six independent water molecules. The five pyridone molecules are all closely similar. In particular, the bond lengths reflect the quinone-like distribution of single and double bonds, with N—C 1.341 (3)–1.355 (3), av. 1.346 Å, Cn2—Cn3 and Cn5—Cn6 1.356 (3)–1.372 (3), av. 1.362 Å, Cn3—Cn4 and Cn4—Cn5 1.417 (3)–1.433 (3), av. 1.426 Å, Cn4═O 1.258 (2)–1.278 (2), av. 1.272 Å. The C═O bond of the fifth molecule is significantly shorter than the others, which may be due to its different hydrogen-bonding environment (see below). The ring angles are all slightly greater than 120° except for the angle at Cn4, which is narrowed to an average of 115.40°. Closely similar dimensions, where applicable, are also observed in the analogous 4-thione (Flakus et al., 2001) and the 4-nitrophenol adduct (Evans et al., 1998). Individual values for each molecule are available in the deposited material.

The molecular packing was expected to be straightforward, with chains of pyridone molecules linked by head-to-tail hydrogen bonds of the form N—H···O; this structure type is observed for the sulfur analogue (Flakus et al., 2001). In one region of the structure, at y ≈ 0.4, such chains are indeed observed (Fig. 1) parallel to the diagonal [101]. One chain is composed of molecules 1 and 2, and another of molecules 3 and 4. The chains are slightly angled at the H atoms of the NH groups (Table 2) and rather more so at the O atoms [H···O═C 129.9 (8)–136.0 (8)°]. There is no additional secondary bonding between the two chains. All four independent molecules are approximately coplanar [interplanar angles: molecule 1/molecule 2 1.39 (7), 3/4 2.03 (7), 2/3 2.38 (7)°].

The second region of the structure, at y ≈ 0.15, consists of layers involving pyridone molecule 5 and all six water molecules (Fig. 2). There are two clearly defined chain substructures in the layer, both parallel to the x axis. One is composed solely of water molecules 1–4, connected by hydrogen bonds; the other is of the form [···pyridone—(H₂O)₂···]_n, whereby the two waters O5 and O6 are acceptors in a three-centre hydrogen bond from the NH group of one pyridone and donors to the O═C group of the next. It is this chain that is responsible for the overall lack of inversion symmetry. The two chains are linked by hydrogen bonds O5—H···O1W and O6—H···O4W, but also involve some non-classical hydrogen bonds (see below).

The two main components of the packing, the purely pyridone layer and the pyridone/water layer, are linked (Fig. 3) by four independent hydrogen bonds of the form water H···pyridone O. Pyridone 5 is approximately perpendicular to the pyridones of the first layer [e.g. 4/5, interplanar angle 85.85 (5)°].

The hydrogen bonding described so far exhausts the set of classical hydrogen-bond donors, but the waters numbered 2, 3, 5 and 6 still have an acceptor site free. Accordingly, non-classical H bonds of the form C—H···O are observed in the water/pyridone layer (Fig. 2; H53···O2W, H56···O3W and H52···O6W) and between layers (H22···O5W; this interaction is not shown in Fig. 3 because the bonds C22—H22 are eclipsed).

S2. Experimental

Anhydrous 4-pyridone (Sigma-Aldrich) was dissolved in acetone and the solvent was allowed to evaporate slowly. Much microcrystalline material was formed, but also some well formed tablets and prisms.

S3. Refinement

Despite centric E-statistics, the structure could not be solved in space group P2₁/m, which was assigned by the crystallographic software. The space group was therefore changed to P2₁, whereupon direct methods yielded a solution with four recognisable pyridone molecules (numbers 1–4, see Discussion) and four single peaks tentatively assigned as water O atoms (also numbers 1–4). The remaining residues (one pyridone and two waters) were identified, after appropriate refinement, in difference syntheses, but only as double images, from which the correct positions were obtained by trial and error. Inspection of the coordinates shows that the four pyridones and four waters originally located correspond closely to space group P2₁/n, with a pseudo-inversion centre at ca 1/4, 0.15, 0.25. The lack of systematic absences corresponding to P2₁/n shows that the additional symmetry cannot be global.

Hydrogen atoms bonded to N or O were refined freely but with chemically equivalent X—O bond lengths restrained equal. Other H atoms were included using a riding model starting from calculated positions. Displacement parameter components along common bonds were restrained using the equal DELU instruction in SHELXL97 (Sheldrick, 1997).

The anomalous scattering is not sufficient to determine the absolute structure, and Friedel pairs were therefore merged.

A rigid-body libration correction (Schomaker & Trueblood, 1968) was successfully applied to all five 4-pyridone molecules; corrected bond lengths may be found in the deposited material. In the discussion, uncorrected values are quoted for consistency with other related structures.

Computing details

Data collection: Bruker SMART (1998); cell refinement: Bruker SAINT (1998); data reduction: Bruker SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Siemens XP (1994); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The layer of four independent 4-pyridone molecules at y ≈ 0.4, showing the atom-numbering scheme. Ellipsoids correspond to 30% probability levels; H atom radii are arbitrary. H bonds are indicated by dashed lines.
	Fig. 2. The layer of six independent waters and the fifth independent 4-pyridone molecule at y ≈ 0.15, showing the atom-numbering scheme. Ellipsoids correspond to 30% probability levels; H atom radii are arbitrary. H bonds are indicated by dashed lines.
	Fig. 3. Side view of the layer structure of the title compound, showing the hydrogen bonds that connect the layers. All radii are arbitrary. H atoms not involved in hydrogen bonding are omitted.

4-pyridone 6/5 hydrate

Crystal data

C5H5NO·1.2H2O	F(000) = 620
Mr = 116.72	Dx = 1.321 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 8.6689 (8) Å	Cell parameters from 5938 reflections
b = 17.6441 (16) Å	θ = 2.3–30.2°
c = 9.6101 (8) Å	µ = 0.10 mm^−1
β = 93.283 (3)°	T = 133 K
V = 1467.5 (2) Å^3	Rectangular tablet, colourless
Z = 10	0.24 × 0.18 × 0.12 mm

Data collection

Bruker SMART 1000 CCD diffractometer	3403 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 30.0°, θmin = 2.1°
Detector resolution: 8.192 pixels mm^-1	h = −12→12
ω– & ϕ–scan	k = −24→24
18869 measured reflections	l = −13→13
4431 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0548P)^2] where P = (Fo^2 + 2Fc^2)/3
4431 reflections	(Δ/σ)max = 0.001
438 parameters	Δρmax = 0.32 e Å^−3
137 restraints	Δρmin = −0.18 e Å^−3

Special details

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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 6.7685 (0.0030) x - 1.7817 (0.0137) y + 6.3455 (0.0035) z = 2.6354 (0.0064)

* 0.0043 (0.0013) N11 * 0.0045 (0.0014) C12 * -0.0092 (0.0015) C13 * -0.0012 (0.0015) C14 * -0.0033 (0.0014) C15 * -0.0016 (0.0013) C16 * 0.0066 (0.0010) O11

Rms deviation of fitted atoms = 0.0051

- 6.6799 (0.0026) x - 2.1340 (0.0140) y + 6.4281 (0.0038) z = 2.7780 (0.0065)

Angle to previous plane (with approximate e.s.d.) = 1.39 (0.07)

* 0.0093 (0.0014) N21 * 0.0019 (0.0014) C22 * -0.0106 (0.0014) C23 * -0.0064 (0.0015) C24 * -0.0113 (0.0016) C25 * 0.0025 (0.0015) C26 * 0.0146 (0.0010) O21

Rms deviation of fitted atoms = 0.0092

6.7604 (0.0029) x + 1.4261 (0.0138) y - 6.3847 (0.0035) z = 0.5257 (0.0072)

Angle to previous plane (with approximate e.s.d.) = 2.38 (0.07)

* -0.0067 (0.0013) N31 * 0.0008 (0.0013) C32 * 0.0062 (0.0014) C33 * 0.0007 (0.0015) C34 * 0.0090 (0.0014) C35 * -0.0021 (0.0013) C36 * -0.0078 (0.0010) O31

Rms deviation of fitted atoms = 0.0058

6.7644 (0.0024) x + 2.0421 (0.0130) y - 6.3261 (0.0035) z = 0.5963 (0.0062)

Angle to previous plane (with approximate e.s.d.) = 2.03 (0.07)

* -0.0062 (0.0013) N41 * 0.0002 (0.0014) C42 * 0.0061 (0.0015) C43 * 0.0019 (0.0015) C44 * 0.0086 (0.0014) C45 * -0.0023 (0.0013) C46 * -0.0083 (0.0010) O41

Rms deviation of fitted atoms = 0.0057

- 0.2110 (0.0042) x + 16.9926 (0.0037) y + 2.5860 (0.0065) z = 3.2404 (0.0020)

Angle to previous plane (with approximate e.s.d.) = 85.85 (0.05)

* -0.0168 (0.0015) N51 * -0.0013 (0.0015) C52 * 0.0162 (0.0016) C53 * 0.0083 (0.0016) C54 * 0.0163 (0.0015) C55 * -0.0012 (0.0014) C56 * -0.0216 (0.0011) O51

Rms deviation of fitted atoms = 0.0139

==============================================================================

Libration-corrected bond lengths:

N11—C12 1.350 C12—C13 1.366 C13—C14 1.431 C14—C15 1.436 N11—C16 1.354 C15—C16 1.367 C14—O11 1.279

N21—C22 1.358 C22—C23 1.367 C23—C24 1.428 C24—C25 1.434 N21—C26 1.353 C25—C26 1.368 C24—O21 1.282

N31—C32 1.348 C32—C33 1.376 C33—C34 1.435 C34—C35 1.441 N31—C36 1.363 C35—C36 1.360 C34—O31 1.276

N41—C42 1.354 C42—C43 1.362 C43—C44 1.436 C44—C45 1.436 N41—C46 1.354 C45—C46 1.365 C44—O41 1.279

N51—C52 1.355 C52—C53 1.368 C53—C54 1.438 C54—C55 1.442 N51—C56 1.353 C55—C56 1.366 C54—O51 1.267

============================================================================== H bond acceptor geometry:

130.53 (0.82) H21_$7 - O11 - C14 136.04 (0.82) H11 - O21 - C24 131.45 (0.86) H41_$7 - O31 - C34 129.93 (0.84) H31 - O41 - C44

Operator $7: 1 + x,y,1 + z

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.

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

	x	y	z	Uiso*/Ueq
N11	0.34454 (18)	0.39604 (10)	0.89470 (17)	0.0280 (4)
H11	0.285 (3)	0.3782 (14)	0.823 (2)	0.044 (7)*
C12	0.3539 (2)	0.47011 (12)	0.9255 (2)	0.0321 (4)
H12	0.2925	0.5051	0.8714	0.039*
C13	0.4491 (2)	0.49655 (11)	1.0323 (2)	0.0317 (4)
H13	0.4545	0.5494	1.0505	0.038*
C14	0.5406 (2)	0.44556 (11)	1.11688 (18)	0.0234 (4)
C15	0.5262 (2)	0.36750 (11)	1.07927 (19)	0.0261 (4)
H15	0.5849	0.3306	1.1311	0.031*
C16	0.4295 (2)	0.34516 (11)	0.9701 (2)	0.0283 (4)
H16	0.4220	0.2929	0.9469	0.034*
O11	0.62907 (15)	0.46848 (8)	1.21890 (13)	0.0299 (3)
N21	−0.16419 (18)	0.40300 (10)	0.39677 (17)	0.0270 (3)
H21	−0.236 (2)	0.4182 (14)	0.330 (2)	0.041 (7)*
C22	−0.0955 (2)	0.45434 (11)	0.4841 (2)	0.0293 (4)
H22	−0.1223	0.5063	0.4740	0.035*
C23	0.0114 (2)	0.43330 (11)	0.58622 (19)	0.0265 (4)
H23	0.0585	0.4707	0.6457	0.032*
C24	0.0531 (2)	0.35612 (11)	0.60456 (18)	0.0232 (4)
C25	−0.0214 (2)	0.30419 (11)	0.5091 (2)	0.0317 (4)
H25	0.0030	0.2518	0.5151	0.038*
C26	−0.1275 (2)	0.32924 (12)	0.4093 (2)	0.0319 (4)
H26	−0.1767	0.2937	0.3472	0.038*
O21	0.15002 (16)	0.33383 (8)	0.70115 (14)	0.0306 (3)
N31	0.79731 (18)	0.40826 (10)	0.85413 (17)	0.0282 (4)
H31	0.730 (2)	0.3954 (15)	0.785 (2)	0.048 (7)*
C32	0.8781 (2)	0.35516 (12)	0.9267 (2)	0.0293 (4)
H32	0.8652	0.3034	0.9011	0.035*
C33	0.9790 (2)	0.37347 (12)	1.03671 (19)	0.0286 (4)
H33	1.0348	0.3346	1.0860	0.034*
C34	1.0004 (2)	0.45071 (11)	1.07752 (19)	0.0253 (4)
C35	0.9125 (2)	0.50502 (11)	0.9953 (2)	0.0294 (4)
H35	0.9230	0.5575	1.0160	0.035*
C36	0.8145 (2)	0.48244 (12)	0.8882 (2)	0.0295 (4)
H36	0.7566	0.5195	0.8359	0.035*
O31	1.09160 (16)	0.47017 (8)	1.17975 (14)	0.0327 (3)
N41	0.29806 (18)	0.40004 (10)	0.35458 (16)	0.0264 (3)
H41	0.236 (3)	0.4158 (16)	0.286 (2)	0.048 (7)*
C42	0.3630 (2)	0.45320 (11)	0.44013 (19)	0.0275 (4)
H42	0.3347	0.5048	0.4264	0.033*
C43	0.4677 (2)	0.43495 (11)	0.54533 (19)	0.0276 (4)
H43	0.5117	0.4737	0.6037	0.033*
C44	0.5122 (2)	0.35781 (11)	0.56864 (18)	0.0245 (4)
C45	0.4410 (2)	0.30396 (11)	0.4740 (2)	0.0282 (4)
H45	0.4670	0.2518	0.4831	0.034*
C46	0.3364 (2)	0.32642 (12)	0.37113 (19)	0.0271 (4)
H46	0.2896	0.2896	0.3101	0.033*
O41	0.60874 (15)	0.33784 (8)	0.66703 (14)	0.0320 (3)
N51	−0.0834 (2)	0.14928 (10)	0.2589 (2)	0.0412 (5)
H51	0.017 (2)	0.1510 (18)	0.266 (3)	0.067 (9)*
C52	−0.1589 (2)	0.16775 (12)	0.1374 (3)	0.0387 (5)
H52	−0.1014	0.1803	0.0593	0.046*
C53	−0.3158 (2)	0.16886 (12)	0.1240 (2)	0.0304 (4)
H53	−0.3661	0.1825	0.0372	0.036*
C54	−0.4060 (2)	0.14981 (11)	0.23876 (19)	0.0255 (4)
C55	−0.3185 (2)	0.13207 (11)	0.36554 (19)	0.0288 (4)
H55	−0.3710	0.1201	0.4468	0.035*
C56	−0.1618 (2)	0.13211 (11)	0.3713 (2)	0.0365 (5)
H56	−0.1065	0.1198	0.4564	0.044*
O51	−0.55130 (15)	0.14771 (10)	0.22918 (15)	0.0408 (4)
O1W	0.36109 (18)	0.11160 (9)	0.68042 (16)	0.0394 (4)
H01	0.364 (3)	0.0666 (10)	0.724 (2)	0.044 (7)*
H02	0.442 (3)	0.1396 (16)	0.708 (3)	0.073 (10)*
O2W	0.61606 (18)	0.19240 (9)	0.76806 (17)	0.0399 (4)
H03	0.615 (3)	0.2382 (10)	0.730 (2)	0.046 (7)*
H04	0.699 (3)	0.1670 (16)	0.746 (3)	0.069 (9)*
O3W	0.87931 (18)	0.11233 (9)	0.71260 (17)	0.0427 (4)
H05	0.880 (3)	0.0710 (11)	0.764 (2)	0.056 (8)*
H06	0.959 (3)	0.1417 (15)	0.736 (3)	0.067 (9)*
O4W	1.13993 (18)	0.19376 (9)	0.80711 (16)	0.0379 (4)
H07	1.146 (3)	0.2382 (10)	0.765 (2)	0.048 (7)*
H08	1.217 (3)	0.1689 (16)	0.770 (3)	0.072 (10)*
O5W	0.21656 (15)	0.12725 (9)	0.40858 (15)	0.0368 (3)
H09	0.260 (3)	0.1200 (17)	0.4918 (17)	0.062 (8)*
H010	0.299 (2)	0.1368 (17)	0.357 (3)	0.069 (9)*
O6W	0.18503 (16)	0.20068 (9)	0.09728 (16)	0.0366 (3)
H011	0.280 (2)	0.1890 (17)	0.121 (3)	0.074 (10)*
H012	0.176 (3)	0.1981 (16)	0.0061 (15)	0.053 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N11	0.0268 (8)	0.0299 (9)	0.0265 (8)	−0.0041 (7)	−0.0051 (7)	−0.0016 (7)
C12	0.0328 (10)	0.0296 (11)	0.0324 (10)	0.0006 (8)	−0.0116 (8)	0.0016 (9)
C13	0.0353 (10)	0.0230 (10)	0.0352 (11)	0.0018 (8)	−0.0115 (8)	−0.0012 (8)
C14	0.0233 (8)	0.0264 (10)	0.0202 (9)	−0.0017 (7)	−0.0010 (7)	0.0009 (7)
C15	0.0282 (9)	0.0227 (10)	0.0272 (9)	0.0016 (7)	−0.0013 (7)	0.0023 (7)
C16	0.0331 (10)	0.0246 (10)	0.0269 (9)	−0.0037 (8)	−0.0008 (8)	−0.0014 (7)
O11	0.0311 (7)	0.0295 (8)	0.0278 (7)	−0.0002 (6)	−0.0100 (5)	−0.0008 (6)
N21	0.0260 (8)	0.0282 (9)	0.0261 (8)	0.0014 (7)	−0.0043 (6)	0.0021 (7)
C22	0.0334 (10)	0.0220 (10)	0.0324 (10)	0.0018 (8)	−0.0008 (8)	0.0013 (8)
C23	0.0308 (9)	0.0254 (10)	0.0230 (9)	−0.0019 (8)	−0.0020 (7)	−0.0043 (7)
C24	0.0230 (8)	0.0252 (10)	0.0211 (8)	−0.0028 (7)	−0.0018 (7)	−0.0003 (7)
C25	0.0379 (10)	0.0206 (9)	0.0349 (10)	0.0019 (8)	−0.0122 (8)	−0.0030 (8)
C26	0.0338 (10)	0.0255 (10)	0.0349 (10)	−0.0004 (8)	−0.0116 (8)	−0.0045 (8)
O21	0.0337 (7)	0.0282 (7)	0.0285 (7)	−0.0017 (6)	−0.0111 (5)	0.0008 (6)
N31	0.0269 (8)	0.0356 (10)	0.0215 (8)	−0.0042 (7)	−0.0037 (7)	0.0019 (7)
C32	0.0323 (10)	0.0271 (11)	0.0282 (10)	−0.0017 (8)	−0.0008 (8)	−0.0021 (8)
C33	0.0312 (10)	0.0260 (10)	0.0279 (10)	0.0041 (8)	−0.0040 (8)	0.0018 (8)
C34	0.0233 (8)	0.0279 (10)	0.0246 (9)	−0.0010 (7)	−0.0004 (7)	0.0003 (8)
C35	0.0323 (9)	0.0254 (10)	0.0301 (10)	−0.0004 (8)	−0.0030 (8)	0.0040 (8)
C36	0.0300 (9)	0.0307 (11)	0.0273 (9)	−0.0001 (8)	−0.0021 (8)	0.0072 (8)
O31	0.0338 (7)	0.0294 (8)	0.0333 (7)	0.0004 (6)	−0.0123 (6)	−0.0025 (6)
N41	0.0259 (8)	0.0301 (9)	0.0226 (8)	0.0017 (7)	−0.0030 (6)	−0.0009 (7)
C42	0.0314 (10)	0.0232 (10)	0.0274 (9)	0.0012 (7)	−0.0030 (8)	−0.0014 (8)
C43	0.0317 (10)	0.0244 (10)	0.0263 (10)	−0.0008 (8)	−0.0032 (8)	−0.0022 (7)
C44	0.0243 (9)	0.0272 (10)	0.0215 (9)	−0.0006 (7)	−0.0014 (7)	−0.0028 (7)
C45	0.0306 (9)	0.0235 (9)	0.0299 (10)	0.0034 (7)	−0.0030 (8)	−0.0050 (7)
C46	0.0253 (9)	0.0300 (10)	0.0257 (9)	−0.0006 (8)	−0.0016 (7)	−0.0057 (8)
O41	0.0331 (7)	0.0321 (8)	0.0294 (7)	0.0009 (6)	−0.0110 (6)	0.0008 (6)
N51	0.0204 (8)	0.0299 (10)	0.0728 (14)	0.0011 (7)	−0.0016 (8)	−0.0129 (9)
C52	0.0349 (11)	0.0253 (11)	0.0577 (14)	−0.0040 (8)	0.0189 (10)	−0.0075 (10)
C53	0.0349 (10)	0.0248 (10)	0.0317 (10)	0.0009 (8)	0.0045 (8)	−0.0013 (8)
C54	0.0219 (8)	0.0246 (10)	0.0295 (9)	0.0028 (7)	−0.0026 (7)	−0.0009 (7)
C55	0.0349 (10)	0.0233 (10)	0.0275 (9)	0.0015 (8)	−0.0049 (7)	0.0013 (8)
C56	0.0368 (10)	0.0208 (10)	0.0494 (12)	0.0053 (8)	−0.0197 (9)	−0.0066 (9)
O51	0.0204 (6)	0.0621 (10)	0.0395 (8)	0.0031 (6)	−0.0005 (6)	−0.0029 (7)
O1W	0.0432 (9)	0.0305 (9)	0.0424 (9)	0.0004 (7)	−0.0141 (7)	0.0075 (7)
O2W	0.0414 (9)	0.0343 (10)	0.0435 (9)	0.0016 (7)	−0.0006 (7)	0.0092 (7)
O3W	0.0401 (9)	0.0324 (10)	0.0538 (10)	−0.0011 (7)	−0.0134 (7)	0.0102 (7)
O4W	0.0405 (9)	0.0318 (9)	0.0405 (9)	0.0006 (7)	−0.0048 (7)	0.0083 (7)
O5W	0.0254 (7)	0.0468 (9)	0.0371 (8)	−0.0071 (6)	−0.0066 (6)	0.0104 (7)
O6W	0.0260 (7)	0.0451 (9)	0.0387 (8)	0.0026 (6)	0.0006 (6)	0.0018 (7)

Geometric parameters (Å, º)

N11—C12	1.342 (3)	C44—C45	1.431 (3)
N11—C16	1.346 (3)	C45—C46	1.362 (3)
C12—C13	1.362 (3)	N51—C56	1.343 (3)
C13—C14	1.423 (3)	N51—C52	1.346 (3)
C14—O11	1.275 (2)	C52—C53	1.359 (3)
C14—C15	1.428 (3)	C53—C54	1.428 (3)
C15—C16	1.363 (3)	C54—O51	1.258 (2)
N21—C26	1.343 (3)	C54—C55	1.432 (3)
N21—C22	1.350 (3)	C55—C56	1.356 (3)
C22—C23	1.362 (3)	N11—H11	0.893 (16)
C23—C24	1.417 (3)	N31—H31	0.885 (16)
C24—O21	1.278 (2)	N21—H21	0.909 (16)
C24—C25	1.425 (3)	N41—H41	0.870 (16)
C25—C26	1.364 (3)	N51—H51	0.868 (17)
N31—C32	1.341 (3)	O1W—H02	0.889 (15)
N31—C36	1.355 (3)	O2W—H03	0.888 (15)
C32—C33	1.372 (3)	O2W—H04	0.879 (15)
C33—C34	1.427 (3)	O3W—H06	0.883 (15)
C34—O31	1.272 (2)	O5W—H09	0.875 (15)
C34—C35	1.433 (3)	O6W—H012	0.876 (14)
C35—C36	1.356 (3)	O4W—H07	0.887 (15)
N41—C46	1.348 (3)	O4W—H08	0.895 (15)
N41—C42	1.349 (2)	O5W—H010	0.907 (15)
C42—C43	1.359 (3)	O6W—H011	0.870 (15)
C43—C44	1.429 (3)	O1W—H01	0.895 (15)
C44—O41	1.276 (2)	O3W—H05	0.879 (15)
C12—N11—C16	120.42 (17)	O41—C44—C45	121.91 (18)
N11—C12—C13	121.76 (19)	C43—C44—C45	115.49 (17)
C12—C13—C14	120.51 (19)	C46—C45—C44	120.90 (18)
O11—C14—C13	121.96 (18)	N41—C46—C45	121.02 (18)
O11—C14—C15	122.72 (17)	C56—N51—C52	120.59 (18)
C13—C14—C15	115.31 (16)	N51—C52—C53	121.3 (2)
C16—C15—C14	120.99 (18)	C52—C53—C54	120.9 (2)
N11—C16—C15	120.99 (19)	O51—C54—C53	122.72 (17)
C26—N21—C22	120.05 (17)	O51—C54—C55	122.32 (17)
N21—C22—C23	121.51 (19)	C53—C54—C55	114.95 (17)
C22—C23—C24	120.63 (18)	C56—C55—C54	120.97 (19)
O21—C24—C23	122.57 (17)	N51—C56—C55	121.28 (19)
O21—C24—C25	121.64 (18)	C12—N11—H11	122.6 (17)
C23—C24—C25	115.78 (16)	C16—N11—H11	117.0 (17)
C26—C25—C24	120.46 (18)	C22—N21—H21	120.1 (17)
N21—C26—C25	121.57 (19)	C26—N21—H21	119.8 (16)
C32—N31—C36	120.14 (17)	C32—N31—H31	120.8 (18)
N31—C32—C33	121.8 (2)	C36—N31—H31	119.1 (18)
C32—C33—C34	120.26 (19)	C42—N41—H41	117.0 (19)
O31—C34—C33	122.35 (18)	C46—N41—H41	122.4 (19)
O31—C34—C35	122.18 (18)	C52—N51—H51	119.8 (18)
C33—C34—C35	115.47 (17)	C56—N51—H51	119.5 (18)
C36—C35—C34	120.81 (19)	H01—O1W—H02	111 (2)
N31—C36—C35	121.49 (19)	H03—O2W—H04	111 (2)
C46—N41—C42	120.46 (17)	H05—O3W—H06	111 (2)
N41—C42—C43	121.77 (19)	H07—O4W—H08	101 (2)
C42—C43—C44	120.35 (18)	H09—O5W—H010	103 (2)
O41—C44—C43	122.60 (17)	H011—O6W—H012	106 (2)
C16—N11—C12—C13	0.4 (3)	O31—C34—C35—C36	−179.01 (18)
N11—C12—C13—C14	−1.1 (3)	C33—C34—C35—C36	1.2 (3)
C12—C13—C14—O11	−178.92 (18)	C32—N31—C36—C35	−0.1 (3)
C12—C13—C14—C15	1.1 (3)	C34—C35—C36—N31	−0.7 (3)
O11—C14—C15—C16	179.50 (17)	C46—N41—C42—C43	−0.2 (3)
C13—C14—C15—C16	−0.5 (3)	N41—C42—C43—C44	−0.2 (3)
C12—N11—C16—C15	0.2 (3)	C42—C43—C44—O41	−179.18 (18)
C14—C15—C16—N11	−0.1 (3)	C42—C43—C44—C45	0.8 (3)
C26—N21—C22—C23	−0.1 (3)	O41—C44—C45—C46	178.94 (18)
N21—C22—C23—C24	−0.5 (3)	C43—C44—C45—C46	−1.0 (3)
C22—C23—C24—O21	−178.28 (18)	C42—N41—C46—C45	0.0 (3)
C22—C23—C24—C25	1.0 (3)	C44—C45—C46—N41	0.7 (3)
O21—C24—C25—C26	178.23 (18)	C56—N51—C52—C53	−0.7 (3)
C23—C24—C25—C26	−1.1 (3)	N51—C52—C53—C54	−0.5 (3)
C22—N21—C26—C25	0.0 (3)	C52—C53—C54—O51	−177.5 (2)
C24—C25—C26—N21	0.6 (3)	C52—C53—C54—C55	1.6 (3)
C36—N31—C32—C33	0.3 (3)	O51—C54—C55—C56	177.53 (19)
N31—C32—C33—C34	0.1 (3)	C53—C54—C55—C56	−1.6 (3)
C32—C33—C34—O31	179.30 (17)	C52—N51—C56—C55	0.7 (3)
C32—C33—C34—C35	−0.9 (3)	C54—C55—C56—N51	0.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N11—H11···O21	0.89 (2)	1.79 (2)	2.674 (2)	171 (2)
N31—H31···O41	0.89 (2)	1.82 (2)	2.667 (2)	161 (3)
N51—H51···O5W	0.87 (2)	2.18 (2)	2.925 (2)	143 (2)
N51—H51···O6W	0.87 (2)	2.41 (2)	3.011 (2)	127 (2)
O1W—H02···O2W	0.89 (2)	1.84 (2)	2.723 (2)	177 (3)
O2W—H03···O41	0.89 (2)	1.86 (2)	2.743 (2)	174 (2)
O2W—H04···O3W	0.88 (2)	1.88 (2)	2.762 (2)	176 (3)
O3W—H06···O4W	0.88 (2)	1.91 (2)	2.785 (2)	171 (3)
O5W—H09···O1W	0.88 (2)	1.97 (2)	2.845 (2)	176 (3)
N21—H21···O11^i	0.91 (2)	1.78 (2)	2.668 (2)	167 (2)
N41—H41···O31^i	0.87 (2)	1.84 (2)	2.686 (2)	163 (3)
O6W—H012···O4W^i	0.88 (1)	1.92 (2)	2.796 (2)	175 (2)
O4W—H07···O21^ii	0.89 (2)	1.80 (2)	2.676 (2)	172 (2)
O4W—H08···O1W^ii	0.90 (2)	1.85 (2)	2.744 (2)	174 (3)
O5W—H010···O51^ii	0.91 (2)	1.85 (2)	2.748 (2)	171 (3)
O6W—H011···O51^ii	0.87 (2)	1.89 (2)	2.715 (2)	158 (3)
O1W—H01···O11^iii	0.90 (2)	1.82 (2)	2.704 (2)	170 (2)
O3W—H05···O31^iv	0.88 (2)	1.87 (2)	2.719 (2)	161 (3)
C53—H53···O2W^i	0.95	2.59	3.463 (3)	153
C56—H56···O3W^v	0.95	2.48	3.298 (3)	145
C22—H22···O5W^vi	0.95	2.57	3.406 (2)	147
C52—H52···O6W	0.95	2.51	3.084 (2)	119

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