Two succinic acid derivatives of 2-ethyl-6-methyl­pyridin-3-ol

Crystals of bis(2-ethyl-3-hy­droxy-6-methyl­pyridinium) succin­ate-succin­ic acid (1/1), C₈H₁₂NO⁺·0.5C₄H₄O₄^2-·0.5C₄H₆O₄, (I), and 2-ethyl-3-hy­droxy-6-methyl­pyridinium hydrogen suc­cinate, C₈H₁₂NO⁺·C₄H₅O₄^-, (II), were obtained by reaction of 2-ethyl-6-methyl­pyridin-3-ol with succinic acid. The succinate anion and succinic acid mol­ecule in (I) are located about centres of inversion. Inter­molecular O-H...O, N-H...O and C-H...O hydrogen bonds are responsible for the formation of a three-dimensional network in the crystal structure of (I) and a two-dimensional network in the crystal structure of (II). Both structures are additionally stabilized by [pi]-[pi] inter­actions between symmetry-related pyridine rings, forming a rod-like cationic arrangement for (I) and cationic dimers for (II).

S1. Comment

A succinic acid derivative of 2-ethyl-6-methylpyridin-3-ol is used as a nootropic drug in medical practice (Voronina, 1992, and references therein). It is also known for its antioxidant (Klebanov et al., 2001), antihypoxant (Luk'yanova et al., 1990), cardioprotective (Golikov et al., 2004; Sidorenko et al., 2011) and antistressor (Tilekeyeva & Sitina, 2005; Sariev & Kravtsova, 2005) effects. As no crystal data are available for any succinic acid derivatives of 2-ethyl-6-methylpyridin-3-ol [Cambridge Structural Database (CSD), Version 5.32, November 2010; Allen, 2002], in the present work we intended to obtain structural information.

Our preliminary investigation, carried out by X-ray powder diffraction, revealed that the reaction of 2-ethyl-6-methylpyridin-3-ol with succinic acid (1:1 molar ratio) could give either one crystalline compound or its mixture with another one (the ratio of these products depends on the reaction conditions). The aim of the present work was to obtain pure crystalline samples of the compounds and investigate their crystal structures using single-crystal X-ray diffraction.

One of the above-mentioned crystalline compounds, bis(2-ethyl-3-hydroxy-6-methylpyridinium) succinate–succinic acid (1/1), (I) (Fig. 1), was obtained directly as a result of the reaction of 2-ethyl-6-methylpyridin-3-ol with succinic acid. A pure sample of another compound, 2-ethyl-3-hydroxy-6-methylpyridinium hydrogen succinate, (II) (Fig. 2), can be prepared by transformation of (I) (see Experimental).

The asymmetric unit of (I) comprises one 2-ethyl-6-methyl-3-hydroxypyridinium cation, half a succinate anion (fully deprotonated) and half a succinic acid molecule. All atoms occupy general positions. The succinate anion and succinic acid molecule are located about centres of inversion, imposing C_i symmetry on both moieties. However, their non-H-atom skeletons show almost planar configurations corresponding to noncrystallographic symmetry C_2h, with r.m.s. deviations from planarity of 0.0056 Å for the succinic acid molecule and 0.0612 Å for the succinate anion (Pilati & Forni, 1998).

In (I), the bond lengths and valence angles are in the expected ranges for all moieties of the compound (Table 1) [Standard reference?]. In the carboxyl group of the succinic acid molecule, the C12—O121(H) bond length of 1.304 (2) Å is longer than the carbonyl group C12—O122 bond length of 1.196 (2) Å. The C10—O101 and C10—O102 bond lengths of the carboxylate groups of the succinate anion are close to each other, being 1.2587 (18) and 1.2327 (19) Å, respectively.

There are hydrogen bonds in the crystal structure of (I) (Table 2 and Fig. 3). Intermolecular O—H···O hydrogen bonds between the succinic acid molecules and the succinate anions connect the components into polymeric chains extending along the [210] direction. Each 2-ethyl-6-methyl-3-hydroxypyridinium cation is bonded to three such polymeric chains through three hydrogen bonds, namely N—H···O, O—H···O and C—H···O, forming a three-dimensional polymeric network. There are additional π–π interactions between the pyridine rings, with centroid–centroid (Cg···Cg) distances of about 3.58 Å [Cg···Cgⁱ; symmetry code: (i) -x, -y + 1, -z + 1] and of about 3.74 Å [Cg···Cgⁱⁱ; symmetry code: (ii) -x + 1, -y + 1, -z + 1]. These π–π interactions result in the formation of a rod-like cationic arrangement extending along the a axis (Fig. 3).

The asymmetric unit of (II) includes one 2-ethyl-6-methyl-3-hydroxypyridinium cation and one hydrogen succinate anion having only one deprotonated carboxyl group. All atoms lie on general positions. The non-H-atom skeleton of the hydrogen succinate anion is almost planar, with a mean deviation of the atoms from the least-squares plane of 0.0076 (12) Å. Bond lengths in the 2-ethyl-6-methyl-3-hydroxypyridinium cation and hydrogen succinate anion are similar to the corresponding values in (I) (Table 3).

Hydrogen bonds in the crystal structure of (II) (Table 4 and Fig. 4) are similar to those in (I), including intermolecular O—H···O, N—H···O and C—H···O hydrogen bonds. However, the supramolecular structure is somewhat different from that of (I). O—H···O hydrogen bonds between the succinate anions form infinite chains running along the b axis. Each 2-ethyl-6-methyl-3-hydroxypyridinium cation is connected to two anionic chains, to one via O—H···O and C—H···O hydrogen bonds and to another through N—H···O hydrogen bonds, forming a two-dimensional network parallel to the (102) plane. There are also π–π interactions between the pyridine rings, with centroid–centroid distances of about 3.52 Å [Cg···Cgⁱⁱⁱ; symmetry code: (iii) -x + 1, -y, -z + 1]. These are responsible for the formation of cationic dimers, shown in Fig. 5. The crystal packing of (II) is shown in Fig. 6.

Related literature

For related literature, see: Allen (2002); Golikov et al. (2004); Klebanov et al. (2001); Luk'yanova, Romanova, Chernobaeva, Lukinykh & Smirnov (1990); Pilati & Forni (1998); Sariev & Kravtsova (2005); Sidorenko et al. (2011); Tilekeyeva & Sitina (2005); Voronina (1992).

S2. Experimental

For the synthesis of (I), 2-ethyl-6-methylpyridin-3-ol (10.0 g, 73 mmol) and succinic acid (8.6 g, 73 mmol) were heated in propan-2-ol under reflux for 1 h. The reaction mixture was filtered and the solution obtained was cooled to room temperature. The precipitated crystals of (I) were collected, washed twice with acetone (10 ml) and dried in air (yield 11.2 g, 44%; m.p. 385–386 K). ¹H NMR (500 MHz, D₂O, δ, p.p.m.): 1.16 (t, 3H, J = 7.5 Hz, CH₂CH₃), 2.43 (s, 4H, CH₂CH₂), 2.48 (s, 3H, CH₃), 2.84 (q, 2H, J = 7.5 Hz, CH₂CH₃), 7.34 (d, 1H, J = 9 Hz, aryl), 7.66 (d, 1H, J = 9 Hz, aryl). Single crystals of (I) suitable for X-ray analysis were selected from the reaction product.

For the synthesis of (II), compound (I) (5.0 g) was dissolved in a propan-2-ol–acetone mixture (9:1 v/v, 70 ml) under reflux. After refluxing for 30 min, the solution obtained was cooled to room temperature. The precipitated crystals were collected and dried in air to give a mixture of (I) and (II), with a melting interval of 385–393 K. To prepare a pure sample of (II), the obtained mixture was heated at 388–391 K in an oil bath for 30 min. The resulting slurry was left to cool to room temperature overnight. The resulting crystalline solid of (II) was ground to a fine polycrystalline powder (yield 3.2 g, 64%; m.p. 392–393 K). The ¹H NMR spectrum of (II) was identical to that of (I). Single crystals of (II) suitable for X-ray analysis can be prepared by crystallization from acetone solutions of (I) or (II), using seed crystals of (II). In the present work, a solution of (I) was used for this purpose.

S3. Refinement

H atoms were included in geometrically calculated positions, with N—H = 0.86 Å, O—H = 0.82 Å and C—H = 0.93–0.97 Å, and refined using a riding model, with U_iso(H) = 1.5U_eq(C,O) for methyl and hydroxy H or 1.2U_eq(C,N) for other H atoms.

Computing details

For both compounds, data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry codes: (a) -x - 1, -y, -z; (b) -x + 1, -y + 1, -z.]
	Fig. 2. The asymmetric unit of (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 3. The hydrogen bonding (dashed lines) in the crystal structure of (I). Symmetry transformations correspond to those in Table 2. π–π interactions between the pyridine rings are also shown as dashed lines. The ethyl groups have been omitted for clarity.
	Fig. 4. The hydrogen bonding (dashed lines) in the crystal structure of (II). Symmetry transformations correspond to those in Table 4.
	Fig. 5. π–π interactions (dashed lines) between the pyridine rings in the crystal structure of (II), forming cationic dimers. The ethyl groups of the cations and the succinate anions have been omitted for clarity.
	Fig. 6. The crystal packing in (II), viewed along the c axis. Dashed lines show hydrogen bonds.

(I) bis(2-ethyl-6-methyl-3-hydroxypyridinium) succinate–succinic acid (1/1)

Crystal data

C8H12NO^+·0.5C4H4O4^2^−·0.5C4H6O4	Z = 2
Mr = 255.27	F(000) = 272
Triclinic, P1	Dx = 1.284 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.3047 (6) Å	Cell parameters from 2735 reflections
b = 8.4660 (7) Å	θ = 2.6–28.3°
c = 11.7559 (10) Å	µ = 0.10 mm^−1
α = 95.747 (1)°	T = 296 K
β = 103.926 (1)°	Prism, colourless
γ = 107.716 (1)°	0.40 × 0.20 × 0.15 mm
V = 660.25 (10) Å^3

Data collection

Bruker APEXII CCD area-detector diffractometer	2717 independent reflections
Radiation source: fine-focus sealed tube	2189 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.014
ϕ and ω scans	θmax = 26.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −9→9
Tmin = 0.961, Tmax = 0.985	k = −10→10
6220 measured reflections	l = −14→14

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0665P)^2 + 0.161P] where P = (Fo^2 + 2Fc^2)/3
2717 reflections	(Δ/σ)max < 0.001
167 parameters	Δρmax = 0.28 e Å^−3
0 restraints	Δρmin = −0.24 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.

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
N1	0.14960 (17)	0.42043 (15)	0.37481 (10)	0.0384 (3)
H1	0.0912	0.3733	0.3012	0.046*
C2	0.16956 (19)	0.58313 (18)	0.40600 (12)	0.0346 (3)
C3	0.2574 (2)	0.65950 (19)	0.52588 (12)	0.0372 (3)
O3	0.26961 (18)	0.82004 (14)	0.55682 (9)	0.0498 (3)
H3	0.2980	0.8452	0.6296	0.075*
C4	0.3273 (2)	0.5662 (2)	0.60597 (13)	0.0449 (4)
H4	0.3888	0.6157	0.6860	0.054*
C5	0.3060 (2)	0.4013 (2)	0.56741 (15)	0.0477 (4)
H5	0.3544	0.3404	0.6216	0.057*
C6	0.2138 (2)	0.3249 (2)	0.44960 (15)	0.0441 (4)
C7	0.1032 (2)	0.6755 (2)	0.31137 (13)	0.0422 (4)
H7A	0.0326	0.7440	0.3400	0.051*
H7B	0.0105	0.5945	0.2415	0.051*
C8	0.2791 (3)	0.7883 (2)	0.27663 (16)	0.0550 (4)
H8A	0.3747	0.8646	0.3464	0.082*
H8B	0.2318	0.8516	0.2201	0.082*
H8C	0.3418	0.7199	0.2415	0.082*
C9	0.1797 (3)	0.1469 (2)	0.3983 (2)	0.0670 (5)
H9A	0.0382	0.0862	0.3684	0.100*
H9B	0.2389	0.0949	0.4592	0.100*
H9C	0.2400	0.1447	0.3344	0.100*
C10	0.7209 (2)	0.1343 (2)	0.13892 (13)	0.0439 (4)
O101	0.88897 (18)	0.24738 (16)	0.15792 (10)	0.0618 (4)
O102	0.6442 (2)	0.08687 (18)	0.21770 (10)	0.0704 (4)
C11	0.6081 (2)	0.0530 (2)	0.01004 (13)	0.0506 (4)
H11A	0.6128	0.1412	−0.0371	0.061*
H11B	0.6763	−0.0173	−0.0189	0.061*
C12	0.2711 (2)	0.3927 (2)	0.05304 (14)	0.0498 (4)
O121	0.0812 (2)	0.3133 (2)	−0.00103 (12)	0.0906 (6)
H121	0.0200	0.2922	0.0487	0.136*
O122	0.33909 (19)	0.4171 (2)	0.15904 (11)	0.0766 (5)
C13	0.3903 (2)	0.4524 (3)	−0.03110 (15)	0.0582 (5)
H13A	0.3338	0.5251	−0.0758	0.070*
H13B	0.3788	0.3556	−0.0876	0.070*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0359 (6)	0.0425 (7)	0.0299 (6)	0.0063 (5)	0.0072 (5)	0.0042 (5)
C2	0.0286 (6)	0.0409 (8)	0.0285 (7)	0.0039 (5)	0.0076 (5)	0.0066 (5)
C3	0.0312 (7)	0.0454 (8)	0.0274 (7)	0.0029 (6)	0.0075 (5)	0.0068 (6)
O3	0.0613 (7)	0.0467 (6)	0.0292 (5)	0.0071 (5)	0.0079 (5)	0.0006 (4)
C4	0.0346 (7)	0.0654 (10)	0.0280 (7)	0.0093 (7)	0.0050 (6)	0.0124 (7)
C5	0.0385 (8)	0.0649 (11)	0.0445 (9)	0.0193 (7)	0.0116 (6)	0.0262 (8)
C6	0.0377 (7)	0.0478 (9)	0.0501 (9)	0.0142 (6)	0.0162 (7)	0.0162 (7)
C7	0.0441 (8)	0.0454 (8)	0.0293 (7)	0.0099 (6)	0.0033 (6)	0.0075 (6)
C8	0.0660 (11)	0.0588 (10)	0.0465 (9)	0.0193 (9)	0.0251 (8)	0.0220 (8)
C9	0.0682 (12)	0.0523 (11)	0.0832 (14)	0.0235 (9)	0.0218 (11)	0.0154 (10)
C10	0.0417 (8)	0.0462 (8)	0.0293 (7)	−0.0007 (6)	0.0080 (6)	−0.0033 (6)
O101	0.0458 (7)	0.0700 (8)	0.0377 (6)	−0.0152 (6)	0.0050 (5)	−0.0046 (5)
O102	0.0657 (8)	0.0830 (9)	0.0285 (6)	−0.0174 (7)	0.0142 (5)	−0.0073 (6)
C11	0.0428 (9)	0.0586 (10)	0.0296 (7)	−0.0074 (7)	0.0099 (6)	−0.0049 (7)
C12	0.0432 (8)	0.0590 (10)	0.0368 (8)	0.0101 (7)	0.0033 (6)	0.0058 (7)
O121	0.0473 (7)	0.1430 (15)	0.0401 (7)	−0.0157 (8)	0.0040 (6)	0.0067 (8)
O122	0.0505 (7)	0.1230 (13)	0.0389 (7)	0.0111 (8)	0.0039 (6)	0.0187 (7)
C13	0.0441 (9)	0.0788 (13)	0.0378 (8)	0.0068 (9)	0.0047 (7)	0.0109 (8)

Geometric parameters (Å, º)

N1—C2	1.3431 (19)	C8—H8C	0.9600
N1—C6	1.350 (2)	C9—H9A	0.9600
N1—H1	0.8600	C9—H9B	0.9600
C2—C3	1.3948 (19)	C9—H9C	0.9600
C2—C7	1.493 (2)	C10—O102	1.2327 (19)
C3—O3	1.3413 (19)	C10—O101	1.2587 (18)
C3—C4	1.391 (2)	C10—C11	1.5142 (19)
O3—H3	0.8200	C11—C11^i	1.507 (3)
C4—C5	1.374 (2)	C11—H11A	0.9700
C4—H4	0.9300	C11—H11B	0.9700
C5—C6	1.377 (2)	C12—O122	1.196 (2)
C5—H5	0.9300	C12—O121	1.305 (2)
C6—C9	1.488 (3)	C12—C13	1.497 (2)
C7—C8	1.521 (2)	O121—H121	0.8200
C7—H7A	0.9700	C13—C13^ii	1.511 (3)
C7—H7B	0.9700	C13—H13A	0.9700
C8—H8A	0.9600	C13—H13B	0.9700
C8—H8B	0.9600
C2—N1—C6	125.30 (13)	C7—C8—H8C	109.5
C2—N1—H1	117.3	H8A—C8—H8C	109.5
C6—N1—H1	117.3	H8B—C8—H8C	109.5
N1—C2—C3	117.99 (13)	C6—C9—H9A	109.5
N1—C2—C7	119.05 (12)	C6—C9—H9B	109.5
C3—C2—C7	122.93 (13)	H9A—C9—H9B	109.5
O3—C3—C4	123.86 (13)	C6—C9—H9C	109.5
O3—C3—C2	117.51 (13)	H9A—C9—H9C	109.5
C4—C3—C2	118.64 (14)	H9B—C9—H9C	109.5
C3—O3—H3	109.5	O102—C10—O101	124.34 (14)
C5—C4—C3	120.26 (14)	O102—C10—C11	118.87 (13)
C5—C4—H4	119.9	O101—C10—C11	116.79 (13)
C3—C4—H4	119.9	C11^i—C11—C10	114.49 (16)
C4—C5—C6	120.86 (14)	C11^i—C11—H11A	108.6
C4—C5—H5	119.6	C10—C11—H11A	108.6
C6—C5—H5	119.6	C11^i—C11—H11B	108.6
N1—C6—C5	116.89 (15)	C10—C11—H11B	108.6
N1—C6—C9	117.60 (16)	H11A—C11—H11B	107.6
C5—C6—C9	125.51 (16)	O122—C12—O121	122.67 (16)
C2—C7—C8	111.91 (13)	O122—C12—C13	124.44 (15)
C2—C7—H7A	109.2	O121—C12—C13	112.87 (14)
C8—C7—H7A	109.2	C12—O121—H121	109.5
C2—C7—H7B	109.2	C12—C13—C13^ii	113.19 (17)
C8—C7—H7B	109.2	C12—C13—H13A	108.9
H7A—C7—H7B	107.9	C13^ii—C13—H13A	108.9
C7—C8—H8A	109.5	C12—C13—H13B	108.9
C7—C8—H8B	109.5	C13^ii—C13—H13B	108.9
H8A—C8—H8B	109.5	H13A—C13—H13B	107.8
C6—N1—C2—C3	−2.3 (2)	C2—N1—C6—C9	−179.50 (14)
C6—N1—C2—C7	175.89 (13)	C4—C5—C6—N1	1.1 (2)
N1—C2—C3—O3	−177.50 (12)	C4—C5—C6—C9	−179.01 (15)
C7—C2—C3—O3	4.4 (2)	N1—C2—C7—C8	−101.27 (16)
N1—C2—C3—C4	2.68 (19)	C3—C2—C7—C8	76.84 (18)
C7—C2—C3—C4	−175.44 (13)	O102—C10—C11—C11^i	12.4 (3)
O3—C3—C4—C5	178.88 (13)	O101—C10—C11—C11^i	−167.5 (2)
C2—C3—C4—C5	−1.3 (2)	O122—C12—C13—C13^ii	0.3 (4)
C3—C4—C5—C6	−0.6 (2)	O121—C12—C13—C13^ii	178.8 (2)
C2—N1—C6—C5	0.4 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O101^iii	0.86	1.91	2.7367 (16)	161
O3—H3···O102^iv	0.82	1.74	2.5534 (15)	176
O121—H121···O101^iii	0.82	1.78	2.6020 (18)	180
C4—H4···O122^iv	0.93	2.46	3.1719 (19)	134

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

(II) 2-ethyl-6-methyl-3-hydroxypyridinium 3-carboxypropionate

Crystal data

C8H12NO^+·C4H5O4^−	F(000) = 544
Mr = 255.27	Dx = 1.288 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6600 reflections
a = 11.4951 (2) Å	θ = 2.4–29.9°
b = 12.4787 (2) Å	µ = 0.10 mm^−1
c = 9.1986 (1) Å	T = 296 K
β = 93.886 (1)°	Prism, colourless
V = 1316.45 (3) Å^3	0.50 × 0.15 × 0.15 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	2733 independent reflections
Radiation source: fine-focus sealed tube	2226 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
ϕ and ω scans	θmax = 26.5°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −14→14
Tmin = 0.952, Tmax = 0.985	k = −15→13
12765 measured reflections	l = −11→9

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.141	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0728P)^2 + 0.4496P] where P = (Fo^2 + 2Fc^2)/3
2733 reflections	(Δ/σ)max = 0.001
167 parameters	Δρmax = 0.28 e Å^−3
0 restraints	Δρmin = −0.24 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.

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
N1	0.66493 (11)	0.06511 (11)	0.66318 (14)	0.0410 (3)
H1	0.7368	0.0479	0.6824	0.049*
C2	0.64131 (13)	0.13587 (13)	0.55524 (17)	0.0412 (4)
C3	0.52507 (13)	0.16437 (13)	0.52291 (17)	0.0390 (4)
O3	0.50401 (10)	0.23467 (11)	0.41467 (14)	0.0547 (4)
H3	0.4343	0.2490	0.4071	0.082*
C4	0.44045 (13)	0.11887 (13)	0.60292 (18)	0.0410 (4)
H4	0.3626	0.1371	0.5829	0.049*
C5	0.47068 (14)	0.04696 (13)	0.71169 (18)	0.0427 (4)
H5	0.4129	0.0167	0.7646	0.051*
C6	0.58527 (14)	0.01897 (13)	0.74378 (17)	0.0406 (4)
C7	0.73940 (15)	0.18238 (18)	0.4772 (2)	0.0606 (5)
H7A	0.7141	0.1925	0.3753	0.073*
H7B	0.8040	0.1322	0.4820	0.073*
C8	0.7806 (2)	0.2884 (2)	0.5412 (3)	0.0891 (8)
H8A	0.7151	0.3353	0.5484	0.134*
H8B	0.8350	0.3204	0.4794	0.134*
H8C	0.8180	0.2769	0.6364	0.134*
C9	0.62727 (18)	−0.05805 (16)	0.8593 (2)	0.0579 (5)
H9A	0.6535	−0.1225	0.8149	0.087*
H9B	0.5648	−0.0747	0.9197	0.087*
H9C	0.6907	−0.0266	0.9178	0.087*
C10	1.20083 (12)	0.24473 (13)	0.86375 (18)	0.0408 (4)
O101	1.29504 (9)	0.19678 (9)	0.86634 (14)	0.0484 (3)
O102	1.19101 (10)	0.34224 (9)	0.89723 (16)	0.0571 (4)
C11	1.09050 (15)	0.18459 (15)	0.8192 (3)	0.0726 (7)
H11A	1.0433	0.1813	0.9025	0.087*
H11B	1.0473	0.2257	0.7441	0.087*
C12	1.10454 (14)	0.07488 (15)	0.7645 (3)	0.0611 (6)
H12A	1.1486	0.0333	0.8384	0.073*
H12B	1.1495	0.0775	0.6791	0.073*
C13	0.99071 (13)	0.01871 (13)	0.7251 (2)	0.0485 (4)
O131	1.00185 (11)	−0.07147 (11)	0.6597 (2)	0.0748 (5)
H131	0.9373	−0.0978	0.6406	0.112*
O132	0.89791 (10)	0.05696 (11)	0.75272 (18)	0.0654 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0271 (6)	0.0491 (8)	0.0461 (7)	0.0078 (5)	−0.0034 (5)	−0.0010 (6)
C2	0.0306 (7)	0.0498 (9)	0.0429 (8)	0.0057 (6)	0.0018 (6)	−0.0011 (7)
C3	0.0324 (7)	0.0415 (8)	0.0424 (8)	0.0059 (6)	−0.0020 (6)	−0.0016 (7)
O3	0.0357 (6)	0.0660 (8)	0.0620 (8)	0.0104 (6)	−0.0005 (5)	0.0189 (6)
C4	0.0266 (7)	0.0449 (9)	0.0513 (9)	0.0049 (6)	−0.0002 (6)	−0.0050 (7)
C5	0.0347 (8)	0.0438 (9)	0.0500 (9)	−0.0011 (6)	0.0051 (6)	−0.0025 (7)
C6	0.0391 (8)	0.0406 (8)	0.0417 (8)	0.0027 (6)	0.0003 (6)	−0.0036 (7)
C7	0.0357 (9)	0.0881 (15)	0.0589 (11)	0.0082 (9)	0.0108 (8)	0.0149 (10)
C8	0.0697 (15)	0.0845 (17)	0.116 (2)	−0.0226 (13)	0.0268 (14)	0.0199 (16)
C9	0.0583 (11)	0.0596 (12)	0.0551 (11)	0.0089 (9)	−0.0028 (8)	0.0100 (9)
C10	0.0281 (7)	0.0372 (8)	0.0561 (9)	−0.0002 (6)	−0.0044 (6)	0.0032 (7)
O101	0.0278 (5)	0.0432 (7)	0.0730 (8)	0.0021 (5)	−0.0065 (5)	−0.0072 (6)
O102	0.0361 (6)	0.0358 (6)	0.0968 (10)	0.0031 (5)	−0.0136 (6)	−0.0049 (6)
C11	0.0297 (9)	0.0487 (11)	0.137 (2)	−0.0018 (8)	−0.0076 (10)	−0.0228 (12)
C12	0.0287 (8)	0.0462 (10)	0.1072 (17)	−0.0027 (7)	−0.0049 (9)	−0.0119 (10)
C13	0.0284 (8)	0.0381 (9)	0.0775 (12)	−0.0003 (6)	−0.0071 (7)	0.0001 (8)
O131	0.0349 (7)	0.0441 (8)	0.1447 (15)	−0.0047 (5)	0.0001 (8)	−0.0253 (8)
O132	0.0279 (6)	0.0638 (9)	0.1031 (11)	0.0001 (5)	−0.0060 (6)	−0.0251 (8)

Geometric parameters (Å, º)

N1—C2	1.343 (2)	C8—H8B	0.9600
N1—C6	1.346 (2)	C8—H8C	0.9600
N1—H1	0.8600	C9—H9A	0.9600
C2—C3	1.395 (2)	C9—H9B	0.9600
C2—C7	1.495 (2)	C9—H9C	0.9600
C3—O3	1.337 (2)	C10—O101	1.2360 (18)
C3—C4	1.381 (2)	C10—O102	1.262 (2)
O3—H3	0.8200	C10—C11	1.506 (2)
C4—C5	1.371 (2)	C11—C12	1.471 (3)
C4—H4	0.9300	C11—H11A	0.9700
C5—C6	1.375 (2)	C11—H11B	0.9700
C5—H5	0.9300	C12—C13	1.507 (2)
C6—C9	1.489 (2)	C12—H12A	0.9700
C7—C8	1.512 (3)	C12—H12B	0.9700
C7—H7A	0.9700	C13—O132	1.211 (2)
C7—H7B	0.9700	C13—O131	1.287 (2)
C8—H8A	0.9600	O131—H131	0.8200
C2—N1—C6	125.29 (13)	C7—C8—H8C	109.5
C2—N1—H1	117.4	H8A—C8—H8C	109.5
C6—N1—H1	117.4	H8B—C8—H8C	109.5
N1—C2—C3	117.90 (14)	C6—C9—H9A	109.5
N1—C2—C7	119.30 (14)	C6—C9—H9B	109.5
C3—C2—C7	122.79 (16)	H9A—C9—H9B	109.5
O3—C3—C4	124.62 (13)	C6—C9—H9C	109.5
O3—C3—C2	116.65 (14)	H9A—C9—H9C	109.5
C4—C3—C2	118.73 (15)	H9B—C9—H9C	109.5
C3—O3—H3	109.5	O101—C10—O102	123.69 (14)
C5—C4—C3	120.33 (14)	O101—C10—C11	118.97 (15)
C5—C4—H4	119.8	O102—C10—C11	117.33 (14)
C3—C4—H4	119.8	C12—C11—C10	116.54 (15)
C4—C5—C6	120.97 (15)	C12—C11—H11A	108.2
C4—C5—H5	119.5	C10—C11—H11A	108.2
C6—C5—H5	119.5	C12—C11—H11B	108.2
N1—C6—C5	116.78 (15)	C10—C11—H11B	108.2
N1—C6—C9	118.00 (14)	H11A—C11—H11B	107.3
C5—C6—C9	125.22 (16)	C11—C12—C13	113.68 (15)
C2—C7—C8	112.30 (17)	C11—C12—H12A	108.8
C2—C7—H7A	109.1	C13—C12—H12A	108.8
C8—C7—H7A	109.1	C11—C12—H12B	108.8
C2—C7—H7B	109.1	C13—C12—H12B	108.8
C8—C7—H7B	109.1	H12A—C12—H12B	107.7
H7A—C7—H7B	107.9	O132—C13—O131	124.03 (15)
C7—C8—H8A	109.5	O132—C13—C12	121.94 (16)
C7—C8—H8B	109.5	O131—C13—C12	114.02 (15)
H8A—C8—H8B	109.5	C13—O131—H131	109.5
C6—N1—C2—C3	−0.1 (2)	C2—N1—C6—C9	179.95 (16)
C6—N1—C2—C7	178.66 (16)	C4—C5—C6—N1	−0.3 (2)
N1—C2—C3—O3	−179.78 (14)	C4—C5—C6—C9	180.00 (16)
C7—C2—C3—O3	1.5 (3)	N1—C2—C7—C8	−94.2 (2)
N1—C2—C3—C4	0.1 (2)	C3—C2—C7—C8	84.5 (2)
C7—C2—C3—C4	−178.65 (16)	O101—C10—C11—C12	−7.1 (3)
O3—C3—C4—C5	179.69 (16)	O102—C10—C11—C12	173.2 (2)
C2—C3—C4—C5	−0.1 (2)	C10—C11—C12—C13	178.72 (19)
C3—C4—C5—C6	0.2 (2)	C11—C12—C13—O132	−8.1 (3)
C2—N1—C6—C5	0.2 (2)	C11—C12—C13—O131	171.4 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O132	0.86	1.92	2.7499 (17)	161
O3—H3···O101^i	0.82	1.75	2.5603 (15)	167
O131—H131···O102^ii	0.82	1.67	2.4882 (16)	177
C4—H4···O102^i	0.93	2.53	3.3617 (19)	149

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