Orthorhombic polymorphs of two trans-4-aminoazoxybenzenes

The two isomeric compounds 4-amino-ONN-azoxy­benzene [or 1-(4-amino­phenyl)-2-phenyl­diazene 2-oxide], i.e. the α isomer, and 4-amino-NNO-azoxy­benzene [or 2-(4-amino­phenyl)-1-phenyl­diazene 2-oxide], i.e. the β isomer, both C₁₂H₁₁N₃O, crystallized from a polar solvent in orthorhombic space groups, and their crystal and molecular structures have been determined using X-ray diffraction. There are no significant differences in the bond lengths and valence angles in the two isomers, in comparison with their monoclinic polymorphs. However, the conformations of the mol­ecules are different due to rotation along the Ar—N bonds. In the α isomer, the benzene rings are twisted by 31.5 (2) and 14.4 (2)° towards the plane of the azoxy group; the torsion angles along the Ar—N bond in the β isomer are 24.3 (3) and 23.5 (3)°. Quantum-mechanical calculations indicate that planar conformations are energetically favourable for both isomers. The N—H...O hydrogen bonds observed in both networks may be responsible for the deformation of these flexible mol­ecules.

S1. Comment

The most effective method of preparation of azoxybenzene and its derivatives involves oxidation of the corresponding azobenzenes. The reaction is not regioselective, and consequently an unsymmetrical substrate gives a mixture of the two isomers. The separation and identification of these isomers is difficult in most cases (Domański & Kyzioł, 2001); X-ray diffraction is the only reliable method of assigning the structure of a particular isomer. We have established the molecular and crystal structures of the monoclinic forms of NNO and ONN trans-4-aminoazoxybenzenes (Domański et al., 2001) but, in further experiments, the same compounds were obtained in different forms displaying higher melting points. Structural investigations revealed that the orthorhombic polymorphs of the isomers arise from crystallization using polar solvents, whereas the monoclinic polymorphs have been obtained by crystallization from non-polar solvents. We present here the molecular and crystal structures of the orthorhombic polymorphs, 4-amino-ONN-azoxybenzene (α isomer), (I), and 4-amino-NNO-azoxybenzene (β isomer), (II). \sch

The molecular structures of the title compounds are shown in Figs. 1a [α isomer, compound (I] and 1 b [β isomer, compound (II)]. The geometry of the bridge is nearly the same in both forms and both isomers. However, the N1—O1 bond is significantly longer (0.03 Å) in the orthorhombic form of the β isomer in comparison with the monoclinic form. Analogous differences are observed in the N1—N2 bond; these are limited to the β (NNO) isomer. The bonds between the bridge and the aromatic rings are of the same length in both isomers and both polymorphs. In all cases, the bond on the oxidized side of the bridge is ca 0.04 Å longer than another one.

The valence angles are typical for the trigonal hybridization of the C and N atoms of the bridge. Some deviations (e.g. 128.2 versus 113.7°) are observed within the C—C—N angles on the unoxidized side of the azoxy group. Such a deformation results from steric interaction between O1 and the H atom in the ortho position.

There are typical features observed in the molecular structures of trans-azoxybenzenes (Domański et al., 2001; Hoesch & Weber, 1977; Krigbaum & Barber, 1971, 1974). There seems to be little evidence for the existence of C—H···O hydrogen bonds, when the shortest O···H distances are 2.37 (2) and 2.34 (2) Å in (I), and 2.45 (2) and 2.25 (2) Å in (II). These distances are shorter than the sum of the van der Waals radii (2.6 Å) given by Pauling (1967).

The sum of the valence angles around the amino N atom [ca 351° in (I) and 354° in (II)], and the distance of atom N3 from the C4/H31/H32 plane [0.18 (1) and 0.15 (1) Å for (I) and (II), respectively], indicate a lack of mesomeric interaction between the amino group and the aromatic ring. The planarity of the amino group has been analysed by two functions of the torsion angles, τ and χ_N (Ferretti et al., 1993), defined as τ = (ω₁ + ω₂)/2, characterizing the rotation around the C—N bond, and χ_N = ω₂ - ω₃ + π(mode 2π), being a measure of the degree of pyramidalization of the N atom (where ω₁ = C5—C4—N3—H32, ω₂ = C3—C4—N3—H31 and ω₃ = C3—C4—N3—H32). These values are τ = 7° and χ_N = 35° in (I), and 1.5 and 29°, respectively, in (II). In both isomers, the χ_N values are intermediate between the extreme value for a regular tetrahedral sp³ configuration (60°) and 0, corresponding to a planar sp² hybridization. In the monoclinic forms, the χ_N factor was bigger in the β isomer (46°) than in the α isomer (26°). It was inferred that the amino group situated on the unoxidized side of the azoxy bridge was more planar (Domański et al., 2001). The dihedral angles between the amino group and the benzene ring are 28 (2)° in (I) and 23 (3)° in (II).

Three planar fragments in the molecular structure of these compounds may be distinguished, namely the benzene ring connected to atom N1 (A), the azoxy group (B) and the other benzene ring (C). In the α isomer, the dihedral angles between the various groups are A/B 13.6 (1), B/C 30.6 (1) and A/C 43.7 (1)°; the analogous values for the β isomer are 23.3 (2), 21.7 (2) and 1.8 (1)°, respectively. Additionally, the twists along the C_aryl—N bonds are observed by the values of the torsion angles of -31.5 (2) and -14.4 (2) for the α isomer, and 24.3 (3) and -23.5 (3)° for the β isomer. These torsion angles are the most significant differences in the conformations of the molecules in the orthorhombic and monoclinic forms. Such conformations exclude effective conjugation between the amino and azoxy groups across the ring, which was suggested in our previous paper (Domański et al., 2001). Steric hindrance around the azoxy group influences the conformations of the molecules, but intermolecular interactions within the crystal network seem to be important as well.

Azoxyarene molecules used to be considered as planar, and hence relatively large torsion angles along the Ar—N bonds were surprising. The results of quantum-mechanical calculations by the B3LYP/6–31G** method (Frisch et al., 1998) are in agreement with this intuitive picture: planar conformations are the most stable for both isomers. The conformational energy contour map (Fig. 2) demonstrates that the conformation with both rings perpendicular to the azoxy bridge is the most unfavourable (20 kcal mol^-1; 1 kcal = 4.184 kJ). However, deviations from planarity observed in the crystal network cause a total energy increase of 1.08 kcal mol^-1 in (II) and 1.51 kcal mol^-1 in (I). Please check rephrasing. Consequently, the conformations of (I) and (II) in the orthorhombic and monoclinic networks may result from intermolecular interactions.

N—H···O hydrogen bonds are observed in both pairs of isomers. The molecular packing of the α and β isomers, with hydrogen bonds shown by dashed lines, is shown in Fig. 3. The IR spectra of the isomers are very similar in the high-wavenumber region, but the spectra of pairs of polymorphs are indistinguishable, e.g. 3447 and 3351 versus 3447 and 3350 cm^-1 in the case of the α isomer. The geometric parameters of the hydrogen bonds confirm the spectroscopic data. In both pairs, the interactions are weak and electrostatic in nature (Desiraju & Steiner, 1999). In spite of this, a closer approach of one molecule to another may cause deformation from the planar conformation in some cases.

In Table 4, Cg2 is the centroid of the unsubstituted ring C1'-C6'.

S2. Experimental

trans-4-(N-Acetylamino)-azobenzene was oxidized with hydrogen peroxide in a mixture of acetic acid and acetic anhydride, as described by Domański et al. (2001). The crude product was hydrolysed and chromatographed. The homogenous fractions were evaporated to dryness and the residues were crystallized from methanol, providing crystals of (I) and (II) suitable for X-ray diffraction studies. The orthorhombic polymorphs of the trans-4-aminoazoxybenzenes were obtained by the above crystallization from methanol. When non-polar solvents were used, the monoclinic forms were obtained. The polymorphs of the isomers were examined by differential scanning calorimetry (DSC). The orthorhombic crystals contain no solvent molecules, although interactions with the solvent must have played an important role in growing the crystals. Their melting points, expressed as minima on the DSC curves, are higher (α 416.2–417.7 K and β 418.5 K) than those of the monoclinic polymorphs (α 408.9 K and β 407 K). Phase transitions of one polymorph into another were not observed.

S3. Refinement

Quantum-mechanical calculations were carried out using GAUSSIAN98 (Frisch et al., 1998). Geometry optimization was performed with the Becke 3LYP density functional theory (DFT) hybrid method (Lee et al., 1988; Becke, 1993) in combination with the 6–31G** basis set. The fully relaxed (Φ-Ψ) conformational energy map in vacuo (30° spacing) of (II) was obtained by the HF method with the 3–21 G basis set. H-atom coordinates were refined, giving C—H distances in the range 0.89 (3)–1.05 (1) Å and N—H distances in the range 0.89 (3)–0.95 (2) Å.

Computing details

For both compounds, data collection: KM-4 CCD Software (Kuma Diffraction, 1999); cell refinement: KM-4 CCD Software; data reduction: KM-4 CCD Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1990); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of (a) the α isomer, (I), and (b) the β isomer, (II). Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The conformational energy contour map of (II) as a function of the N2—N1—C1—C2 and N1—N2—C1'-C2' dihedral angles, obtained by the HF/3–21 G me thod (Frisch et al., 1998). Contours are labelled with energy in kcal mol^-1 (1 kcal = 4.184 kJ) above the minimum energy point at (0°, 0°). * Crystal structure. Please clarify.
	Fig. 3. The packing diagram for (a) the α isomer, (I), and (b) the β isomer, (II), showing the hydrogen bonding (dashed lines).

(I) 1-(4-aminophenyl)-2-phenyldiazene 2-oxide

Crystal data

C12H11N3O	F(000) = 896
Mr = 213.24	Dx = 1.365 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 3160 reflections
a = 12.058 (2) Å	θ = 3.5–26.0°
b = 7.054 (1) Å	µ = 0.09 mm^−1
c = 24.398 (5) Å	T = 90 K
V = 2075.2 (6) Å^3	Prism, orange
Z = 8	0.40 × 0.25 × 0.13 mm

Data collection

Kuma KM-4 with two-dimensional CCD area-detector diffractometer	1617 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.034
Graphite monochromator	θmax = 26.0°, θmin = 3.5°
Detector resolution: 1024x1024 with blocks 2x2 pixels mm^-1	h = −14→14
ω scans	k = −8→6
12684 measured reflections	l = −30→28
2030 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)] = 0.042	Hydrogen site location: difference Fourier map
wR(F^2) = 0.112	All H-atom parameters refined
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0671P)^2 + 0.1381P] where P = (Fo^2 + 2Fc^2)/3
2030 reflections	(Δ/σ)max = 0.001
191 parameters	Δρmax = 0.31 e Å^−3
0 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.

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	1.03622 (10)	0.22089 (19)	0.58438 (6)	0.0256 (4)
N2	0.93829 (11)	0.20682 (19)	0.60288 (6)	0.0262 (3)
O1	1.12684 (9)	0.21446 (17)	0.61182 (5)	0.0303 (3)
C1	0.92224 (13)	0.1715 (2)	0.65905 (6)	0.0234 (4)
C2	0.99093 (14)	0.0673 (2)	0.69493 (6)	0.0240 (4)
C3	0.95795 (13)	0.0352 (2)	0.74829 (7)	0.0231 (4)
C4	0.85716 (13)	0.1060 (2)	0.76819 (6)	0.0223 (4)
C5	0.78915 (13)	0.2084 (2)	0.73222 (7)	0.0245 (4)
C6	0.82079 (13)	0.2373 (2)	0.67901 (7)	0.0245 (4)
N3	0.82633 (13)	0.0769 (2)	0.82143 (6)	0.0307 (4)
C1'	1.04477 (13)	0.2524 (2)	0.52500 (7)	0.0243 (4)
C2'	1.14561 (15)	0.3095 (3)	0.50438 (7)	0.0357 (5)
C3'	1.15634 (15)	0.3386 (3)	0.44821 (7)	0.0388 (5)
C4'	1.06694 (14)	0.3096 (2)	0.41366 (7)	0.0297 (4)
C5'	0.96671 (15)	0.2527 (3)	0.43516 (8)	0.0335 (4)
C6'	0.95509 (15)	0.2239 (3)	0.49113 (8)	0.0323 (4)
H2	1.0605 (14)	0.016 (2)	0.6830 (6)	0.026 (4)*
H3	1.0023 (14)	−0.035 (3)	0.7718 (7)	0.024 (4)*
H5	0.7162 (15)	0.255 (3)	0.7450 (7)	0.030 (5)*
H6	0.7736 (14)	0.311 (3)	0.6540 (7)	0.030 (4)*
H31	0.8538 (16)	−0.024 (3)	0.8408 (9)	0.048 (6)*
H32	0.7525 (18)	0.107 (3)	0.8322 (8)	0.056 (6)*
H2'	1.2060 (17)	0.326 (3)	0.5304 (8)	0.044 (6)*
H3'	1.2311 (18)	0.380 (3)	0.4342 (8)	0.054 (6)*
H4'	1.0720 (10)	0.3304 (19)	0.3713 (6)	0.003 (3)*
H5'	0.9041 (16)	0.236 (3)	0.4108 (8)	0.044 (6)*
H6'	0.8879 (18)	0.187 (3)	0.5065 (8)	0.048 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0211 (7)	0.0266 (7)	0.0289 (8)	0.0023 (6)	−0.0026 (5)	−0.0027 (6)
N2	0.0244 (7)	0.0260 (7)	0.0279 (8)	0.0017 (6)	−0.0008 (6)	0.0004 (6)
O1	0.0188 (6)	0.0454 (7)	0.0265 (6)	−0.0024 (5)	−0.0061 (5)	0.0034 (5)
C1	0.0288 (9)	0.0210 (8)	0.0199 (8)	−0.0033 (7)	−0.0025 (6)	−0.0013 (6)
C2	0.0226 (9)	0.0230 (8)	0.0264 (9)	0.0021 (7)	0.0015 (6)	−0.0017 (7)
C3	0.0237 (8)	0.0209 (8)	0.0243 (8)	0.0014 (7)	−0.0040 (6)	0.0017 (7)
C4	0.0246 (8)	0.0202 (8)	0.0220 (8)	−0.0034 (7)	−0.0003 (6)	−0.0034 (6)
C5	0.0208 (8)	0.0207 (8)	0.0316 (9)	0.0013 (7)	−0.0019 (6)	−0.0040 (7)
C6	0.0248 (9)	0.0208 (8)	0.0276 (9)	0.0007 (7)	−0.0061 (7)	−0.0011 (7)
N3	0.0312 (9)	0.0360 (9)	0.0247 (8)	0.0040 (7)	0.0033 (6)	0.0000 (7)
C1'	0.0290 (9)	0.0226 (8)	0.0210 (8)	0.0057 (7)	0.0008 (6)	0.0004 (6)
C2'	0.0260 (9)	0.0566 (12)	0.0243 (9)	0.0018 (8)	−0.0010 (7)	−0.0027 (8)
C3'	0.0295 (10)	0.0593 (13)	0.0273 (10)	−0.0007 (9)	0.0058 (7)	0.0004 (9)
C4'	0.0357 (10)	0.0313 (9)	0.0221 (9)	0.0080 (7)	0.0002 (7)	−0.0011 (7)
C5'	0.0320 (10)	0.0375 (10)	0.0306 (10)	0.0028 (8)	−0.0068 (8)	0.0007 (8)
C6'	0.0267 (10)	0.0391 (11)	0.0306 (10)	−0.0014 (8)	0.0009 (7)	0.0052 (8)

Geometric parameters (Å, º)

N1—N2	1.268 (2)	C6—H6	0.98 (2)
N1—O1	1.282 (2)	N3—H31	0.92 (2)
N1—C1'	1.469 (2)	N3—H32	0.95 (2)
N2—C1	1.406 (2)	C1'—C6'	1.376 (2)
C1—C6	1.396 (2)	C1'—C2'	1.376 (2)
C1—C2	1.412 (2)	C2'—C3'	1.392 (2)
C2—C3	1.380 (2)	C2'—H2'	0.97 (2)
C2—H2	0.96 (2)	C3'—C4'	1.384 (2)
C3—C4	1.401 (2)	C3'—H3'	1.01 (2)
C3—H3	0.93 (2)	C4'—C5'	1.377 (3)
C4—N3	1.367 (2)	C4'—H4'	1.05 (1)
C4—C5	1.402 (2)	C5'—C6'	1.388 (3)
C5—C6	1.368 (2)	C5'—H5'	0.97 (2)
C5—H5	0.99 (2)	C6'—H6'	0.93 (2)
N2—N1—O1	127.2 (1)	C4—N3—H31	120 (1)
N2—N1—C1'	115.4 (1)	C4—N3—H32	119 (1)
O1—N1—C1'	117.4 (1)	H31—N3—H32	112 (2)
N1—N2—C1	119.3 (1)	C6'—C1'—C2'	121.2 (2)
C6—C1—N2	113.7 (1)	C6'—C1'—N1	121.0 (2)
C6—C1—C2	118.1 (1)	C2'—C1'—N1	117.8 (1)
N2—C1—C2	128.0 (1)	C1'—C2'—C3'	119.0 (2)
C3—C2—C1	120.1 (2)	C1'—C2'—H2'	117 (1)
C3—C2—H2	118 (1)	C3'—C2'—H2'	124 (1)
C1—C2—H2	122 (1)	C4'—C3'—C2'	120.4 (2)
C2—C3—C4	121.2 (2)	C4'—C3'—H3'	122 (1)
C2—C3—H3	120 (1)	C2'—C3'—H3'	117 (1)
C4—C3—H3	119 (1)	C5'—C4'—C3'	119.7 (2)
N3—C4—C3	120.8 (2)	C5'—C4'—H4'	118 (1)
N3—C4—C5	120.9 (2)	C3'—C4'—H4'	122 (1)
C3—C4—C5	118.3 (1)	C4'—C5'—C6'	120.4 (2)
C6—C5—C4	120.5 (2)	C4'—C5'—H5'	119 (1)
C6—C5—H5	120 (1)	C6'—C5'—H5'	121 (1)
C4—C5—H5	120 (1)	C1'—C6'—C5'	119.4 (2)
C5—C6—C1	121.7 (2)	C1'—C6'—H6'	119 (1)
C5—C6—H6	120 (1)	C5'—C6'—H6'	122 (1)
C1—C6—H6	118 (1)
O1—N1—N2—C1	−3.2 (2)	C2—C1—C6—C5	2.2 (2)
C1'—N1—N2—C1	178.3 (1)	N2—N1—C1'—C6'	−14.4 (2)
N1—N2—C1—C6	154.0 (1)	O1—N1—C1'—C6'	166.9 (2)
N1—N2—C1—C2	−31.5 (2)	N2—N1—C1'—C2'	166.1 (2)
C6—C1—C2—C3	−0.9 (2)	O1—N1—C1'—C2'	−12.5 (2)
N2—C1—C2—C3	−175.2 (2)	C6'—C1'—C2'—C3'	0.0 (3)
C1—C2—C3—C4	−0.7 (2)	N1—C1'—C2'—C3'	179.4 (2)
C2—C3—C4—N3	−178.6 (2)	C1'—C2'—C3'—C4'	−0.3 (3)
C2—C3—C4—C5	1.0 (2)	C2'—C3'—C4'—C5'	0.4 (3)
N3—C4—C5—C6	179.8 (2)	C3'—C4'—C5'—C6'	−0.2 (3)
C3—C4—C5—C6	0.2 (2)	C2'—C1'—C6'—C5'	0.2 (3)
C4—C5—C6—C1	−1.9 (2)	N1—C1'—C6'—C5'	−179.2 (2)
N2—C1—C6—C5	177.3 (1)	C4'—C5'—C6'—C1'	−0.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H31···O1^i	0.92 (2)	2.19 (2)	3.083 (2)	165 (2)
N3—H32···O1^ii	0.95 (2)	2.18 (2)	3.063 (2)	154 (2)

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

(II) 2-(4-aminophenyl)-1-phenyldiazene 2-oxide

Crystal data

C12H11N3O	F(000) = 448
Mr = 213.24	Dx = 1.351 Mg m^−3
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 1630 reflections
a = 17.779 (4) Å	θ = 3.7–25.5°
b = 5.535 (1) Å	µ = 0.09 mm^−1
c = 10.652 (2) Å	T = 90 K
V = 1048.2 (4) Å^3	Prism, yellow
Z = 4	0.25 × 0.14 × 0.12 mm

Data collection

Kuma KM-4 with two-dimensional CCD area-detector diffractometer	971 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.047
Graphite monochromator	θmax = 25.5°, θmin = 3.7°
Detector resolution: 1024x1024 with blocks 2x2 pixels mm^-1	h = −21→21
ω scans	k = −4→6
6087 measured reflections	l = −12→12
1033 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)] = 0.031	Hydrogen site location: difference Fourier map
wR(F^2) = 0.067	All H-atom parameters refined
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0422P)^2] where P = (Fo^2 + 2Fc^2)/3
1033 reflections	(Δ/σ)max < 0.001
189 parameters	Δρmax = 0.14 e Å^−3
1 restraint	Δρmin = −0.16 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	0.33494 (10)	0.3120 (3)	0.08364 (17)	0.0184 (4)
N2	0.30226 (11)	0.1672 (3)	0.00566 (18)	0.0189 (4)
N3	0.56451 (12)	0.9054 (4)	−0.1173 (2)	0.0245 (5)
O1	0.32237 (9)	0.3354 (3)	0.20214 (15)	0.0257 (4)
C1	0.39418 (12)	0.4655 (4)	0.0301 (2)	0.0187 (5)
C2	0.41356 (12)	0.6791 (4)	0.0928 (2)	0.0188 (5)
C3	0.47079 (13)	0.8243 (4)	0.0451 (2)	0.0195 (5)
C4	0.50954 (12)	0.7595 (4)	−0.0660 (2)	0.0192 (5)
C5	0.48904 (13)	0.5406 (4)	−0.1269 (2)	0.0197 (5)
C6	0.43173 (13)	0.3961 (4)	−0.0805 (2)	0.0199 (5)
C1'	0.24549 (13)	0.0068 (3)	0.0506 (2)	0.0192 (5)
C2'	0.19978 (13)	0.0337 (4)	0.1586 (2)	0.0206 (5)
C3'	0.14420 (13)	−0.1402 (4)	0.1831 (2)	0.0210 (5)
C4'	0.13417 (13)	−0.3398 (4)	0.1029 (2)	0.0223 (5)
C5'	0.17917 (13)	−0.3650 (4)	−0.0042 (2)	0.0214 (5)
C6'	0.23349 (14)	−0.1914 (4)	−0.0317 (2)	0.0192 (5)
H2	0.3872 (13)	0.720 (4)	0.168 (2)	0.021 (6)*
H3	0.4859 (14)	0.983 (5)	0.087 (3)	0.026 (6)*
H31	0.5825 (16)	1.027 (5)	−0.069 (3)	0.041 (9)*
H32	0.5947 (16)	0.844 (5)	−0.176 (3)	0.039 (9)*
H5	0.5148 (14)	0.493 (4)	−0.202 (2)	0.027 (7)*
H6	0.4181 (15)	0.244 (5)	−0.123 (3)	0.033 (7)*
H2'	0.2066 (14)	0.173 (4)	0.218 (3)	0.031 (7)*
H4'	0.0965 (15)	−0.466 (4)	0.120 (3)	0.032 (7)*
H3'	0.1096 (14)	−0.126 (4)	0.259 (3)	0.031 (7)*
H5'	0.1735 (13)	−0.502 (4)	−0.060 (3)	0.022 (6)*
H6'	0.2639 (16)	−0.203 (4)	−0.109 (3)	0.024 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0180 (9)	0.0197 (9)	0.0174 (11)	0.0002 (8)	−0.0012 (9)	0.0005 (9)
N2	0.0175 (10)	0.0183 (9)	0.0209 (10)	−0.0002 (8)	−0.0010 (8)	−0.0001 (8)
N3	0.0223 (11)	0.0242 (11)	0.0269 (12)	−0.0042 (9)	0.0014 (10)	−0.0004 (9)
O1	0.0266 (9)	0.0351 (9)	0.0155 (9)	−0.0049 (8)	0.0013 (7)	−0.0026 (8)
C1	0.0133 (11)	0.0205 (11)	0.0223 (13)	−0.0002 (9)	−0.0028 (9)	0.0038 (10)
C2	0.0175 (11)	0.0207 (11)	0.0182 (11)	0.0033 (10)	−0.0032 (10)	−0.0004 (10)
C3	0.0174 (11)	0.0182 (11)	0.0228 (12)	0.0016 (9)	−0.0043 (10)	−0.0013 (10)
C4	0.0148 (10)	0.0210 (11)	0.0219 (12)	0.0008 (10)	−0.0047 (10)	0.0044 (9)
C5	0.0207 (11)	0.0227 (11)	0.0157 (12)	0.0052 (9)	0.0003 (10)	−0.0005 (10)
C6	0.0197 (11)	0.0199 (11)	0.0200 (12)	0.0027 (9)	−0.0032 (10)	0.0004 (10)
C1'	0.0184 (11)	0.0189 (10)	0.0203 (12)	0.0011 (10)	−0.0034 (9)	0.0046 (10)
C2'	0.0207 (11)	0.0203 (11)	0.0208 (12)	0.0030 (9)	−0.0006 (10)	−0.0008 (11)
C3'	0.0194 (12)	0.0244 (12)	0.0191 (13)	−0.0014 (10)	0.0019 (10)	0.0001 (10)
C4'	0.0191 (12)	0.0225 (12)	0.0253 (13)	−0.0011 (11)	−0.0009 (10)	0.0023 (10)
C5'	0.0214 (13)	0.0183 (11)	0.0246 (13)	0.0005 (9)	−0.0032 (10)	−0.0017 (11)
C6'	0.0169 (12)	0.0211 (11)	0.0197 (12)	0.0047 (9)	−0.0026 (9)	−0.0008 (10)

Geometric parameters (Å, º)

N1—O1	1.288 (2)	C5—C6	1.387 (3)
N1—N2	1.292 (2)	C5—H5	0.96 (3)
N1—C1	1.469 (3)	C6—H6	0.98 (3)
N2—C1'	1.427 (3)	C1'—C2'	1.416 (3)
N3—C4	1.381 (3)	C1'—C6'	1.421 (3)
N3—H31	0.91 (3)	C2'—C3'	1.404 (3)
N3—H32	0.89 (3)	C2'—H2'	1.00 (3)
C1—C2	1.401 (3)	C3'—C4'	1.408 (3)
C1—C6	1.408 (3)	C3'—H3'	1.02 (3)
C2—C3	1.393 (3)	C4'—C5'	1.400 (4)
C2—H2	0.96 (3)	C4'—H4'	0.98 (3)
C3—C4	1.416 (3)	C5'—C6'	1.393 (3)
C3—H3	1.02 (3)	C5'—H5'	0.97 (2)
C4—C5	1.422 (3)	C6'—H6'	0.99 (3)
O1—N1—N2	127.9 (2)	C5—C6—C1	119.3 (2)
O1—N1—C1	116.5 (2)	C5—C6—H6	120.8 (16)
N2—N1—C1	115.6 (2)	C1—C6—H6	119.9 (16)
N1—N2—C1'	119.2 (2)	C2'—C1'—C6'	119.8 (2)
C4—N3—H31	117.1 (19)	C2'—C1'—N2	127.8 (2)
C4—N3—H32	118.6 (18)	C6'—C1'—N2	112.3 (2)
H31—N3—H32	118 (3)	C3'—C2'—C1'	118.9 (2)
C2—C1—C6	120.9 (2)	C3'—C2'—H2'	119.7 (15)
C2—C1—N1	118.6 (2)	C1'—C2'—H2'	121.5 (15)
C6—C1—N1	120.5 (2)	C2'—C3'—C4'	120.9 (2)
C3—C2—C1	119.5 (2)	C2'—C3'—H3'	121.4 (15)
C3—C2—H2	121.9 (15)	C4'—C3'—H3'	117.6 (15)
C1—C2—H2	118.6 (15)	C5'—C4'—C3'	120.0 (2)
C2—C3—C4	121.0 (2)	C5'—C4'—H4'	117.8 (15)
C2—C3—H3	121.9 (15)	C3'—C4'—H4'	122.2 (15)
C4—C3—H3	117.2 (16)	C6'—C5'—C4'	119.9 (2)
N3—C4—C3	121.8 (2)	C6'—C5'—H5'	119.1 (14)
N3—C4—C5	119.9 (2)	C4'—C5'—H5'	121.0 (14)
C3—C4—C5	118.2 (2)	C5'—C6'—C1'	120.4 (2)
C6—C5—C4	121.2 (2)	C5'—C6'—H6'	120.5 (14)
C6—C5—H5	119.4 (15)	C1'—C6'—H6'	119.1 (14)
C4—C5—H5	119.5 (15)
O1—N1—N2—C1'	−0.9 (3)	C4—C5—C6—C1	−1.1 (3)
C1—N1—N2—C1'	178.23 (18)	C2—C1—C6—C5	0.6 (3)
O1—N1—C1—C2	−22.8 (3)	N1—C1—C6—C5	−178.00 (19)
N2—N1—C1—C2	157.9 (2)	N1—N2—C1'—C2'	24.3 (3)
O1—N1—C1—C6	155.77 (19)	N1—N2—C1'—C6'	−159.9 (2)
N2—N1—C1—C6	−23.5 (3)	C6'—C1'—C2'—C3'	1.3 (3)
C6—C1—C2—C3	−0.1 (3)	N2—C1'—C2'—C3'	176.8 (2)
N1—C1—C2—C3	178.52 (19)	C1'—C2'—C3'—C4'	0.6 (3)
C1—C2—C3—C4	0.2 (3)	C2'—C3'—C4'—C5'	−1.0 (3)
C2—C3—C4—N3	177.6 (2)	C3'—C4'—C5'—C6'	−0.4 (3)
C2—C3—C4—C5	−0.7 (3)	C4'—C5'—C6'—C1'	2.3 (3)
N3—C4—C5—C6	−177.1 (2)	C2'—C1'—C6'—C5'	−2.7 (3)
C3—C4—C5—C6	1.2 (3)	N2—C1'—C6'—C5'	−178.9 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H32···O1^i	0.89 (3)	2.20 (3)	3.085 (3)	172 (3)
N3—H31···Cg2^ii	0.91 (3)	2.56 (3)	3.357 (3)	146 (3)

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