(E)-4-(4-Bromo­phenyl­diazen­yl)-2,6-dimethyl­phenyl acrylate and (E)-2,6-dimethyl-4-(4-methyl­phenyl­diazen­yl)­phenyl acrylate

The crystal structures of the title compounds, C₁₇H₁₅BrN₂O₂, (I), and C₁₈H₁₈N₂O₂, (II), determined at room temperature, have a trans configuration with respect to the diazene linkage, as found for other azo (diazene) derivatives. The aromatic mean planes are nearly coplanar, with a dihedral angle between these planes of 8.31 (2)° for (I) and 3.74 (2)° for (II). In both complexes, the mean plane of the ester group is nearly perpendicular to the aromatic ring planes. In both compounds, the crystal packing involves only π–π and π–ring inter­actions, which combine to stabilize the extended structure.

S1. Comment

Aromatic azo compounds represent the dominant class of synthetic colorant (Peter & Freeman, 1991); they are the most widely used class of dyes because of their versatile application in various fields, such as the dyeing of textiles and fibres, colorants in printing, and high-technology areas, such as ink-jet printers (Catino & Farris, 1985). The reversible inter-conversion between the cis and trans isomers of azo compound facilities the use of these compounds in optical data storage and switching devices (Jeon et al., 2002; Tian et al., 2004). Such optical properties depend on not only the spectroscopic properties of the molecules but also their crystallographic arrangement (Biswas & Umapathy, 2000). There is also interest in their biochemical applications due to their ability to bind to proteins (Ojala et al., 1996). In our ongoing research on azo compounds, in order to provide templates for molecular modeling studies, we have synthesized some diazene derivative compounds and the crystal structures of the title compounds, (I) and (II) (Figs. 1 and 2), have been determined. Both compounds crystallize in the centrosymmetric space group P1; therefore the optical frequency-doubling (or second-harmonic generation) in nonlinear optics does not occur in the solid state. This process can occur only in non-centrosymmetric crystals.

The bond lengths and angles in both structures are within the normally expected ranges. Both structures have a trans configuration about the azo linkage with a nearly planar geometry [the torsion angle of the central –C—N═N—C– unit is 179.0 (2)° for (I) and 178.2 (3)° for (II)] and with C2—C1—N1═N2 and C13—C12—N2═N1 torsion angles of 0.5 (4) and -174.5 (3)°, respectively, in (I), and 2.0 (5) and 177.2 (4)° in (II). These torsion angles suggest delocalization of electron density between the aromatic rings and the azo group. However, the ester and 2,6-dimethyl groups will probably cause the acryloyloxy group to rotate out conjugation with the benzene ring, thus leading to a loss of planarity. The dihedral angle between the aromatic rings is 8.31 (2)° in (I) and 3.74 (2)° in (II).

The ester mean planes of (I) and (II) are approximately planar, with r.m.s. deviations of 0.0240 and 0.0148 Å; the largest deviations from the mean planes are 0.037 (3) and 0.025 (4) Å for atom C10, respectively. The mean planes of the ester groups are nearly perpendicular with the aromatic rings, as indicated by the dihedral angle of 89.6 (1) and 82.7 (1)° in (I), and 88.1 (2) and 87.8 (2)° in (II). The N1—C1 and N2—C12 bond lengths are 1.428 (3) and 1.423 (3) Å for (I), and 1.443 (4) and 1.446 (4) Å for (II), respectively, consistent with that of the conventional single C—N bond length (1.450 Å). Comparing the N2—C12 bond distances in both compounds, we find that the N2—C12 bond length in (I) is slightly shorter than that of compound (II), as a result of the presence of the Br atom in a para position with respect to the azo linkage. This result can be attributed to the electron-withdrawing groups attached to the benzene ring.

The N═N bond lengths [N1═N2 = 1.252 (3) Å for (I) and 1.241 (4) Å for (II)] in both compounds are indicative of significant double-bond character, as has been observed in other trans-azo compound (Kocaokutgen et al., 2003; Soylu et al., 2004). The C—Br bond distance in (I) is consistent with that in 2-{(E)-3-[(E)-4-bromophenyliminomethyl]-4-hydroxyphenyldiazenyl}benzoic acid toluene hemisolvate (Linden et al., 2006) and in (E)-5-(4-bromophenyldiazenyl) salicylaldehyde (Şahin et al., 2005). The O2═C9 bond distance in both compounds is consistent with the value of the C═O double bond in other ester compounds (Kocaokutgen et al., 2005).

In the extended structure of (I) and (II), there are no intra- or intermolecular hydrogen-bonding interactions. The crystal packing of (I) features π–π and π-ring interactions, which form supramolecular motifs extending along the crystallographic a axis (Fig. 3), while in (II), the crystal packing comprises only π–π interactions (Fig. 4). An intermolecular π–π contact occurs between the two symmetry-related aromatic rings (C1–C6: ring A; C12–C17: ring B) of neighbouring azo molecules. Rings A and B are oriented in such a way that the perpendicular distance from A to Bⁱ is 3.310 Å for (I) and 3.529 Å for (II), the closest interatomic distance is C3···C12ⁱ [3.466 (4) Å; symmetry code (i): 1 + x, y, z] for (I) and C2···C13ⁱ [3.564 (5) Å; symmetry code (i): 1 + x, y, z] for (II), and the dihedral angles between the planes of the rings are 8.31 (2)° for (I) and 3.74 (2)° for (II). The distance between the ring centroids is 3.857 (2) Å for (I) and 3.756 (2) Å for (II). Ring A is also involved in an intermolecular C—H···π interaction with atom C10 of the ester group in (I). The distance between atom H10 and the centre of ring A (CgA) is 2.902 Å, the distance between atom H10 and the plane of ring A is 2.900 Å, and the C10—H10···CgAⁱ angle is 165.4°. A three-dimensional network in the crystal structure of both complexes is constructed from van der Waals forces between parallel associations formed by π–π and π-ring interactions. There is strong short contact between atoms C17 and C17ⁱⁱ [symmetry code: (ii) -x, -y, 1 - z] [C17···C17ⁱⁱ = 3.685 (4) Å] for I and O2 and C18ⁱⁱⁱ [symmetry code (iii): x + 1, y, z + 1] atoms [O2···C18ⁱⁱⁱ = 3.570 (5) Å] for (I)I.

Related literature

For related literature, see: Biswas & Umapathy (2000); Catino & Farris (1985); Jeon et al. (2002); Kocaokutgen et al. (2003, 2005); Linden et al. (2006); Ojala et al. (1996); Peter & Freeman (1991); Soylu et al. (2004); Tian et al. (2004); Şahin et al. (2005).

S2. Experimental

For the syntheses of azo-ester compounds containing an acryloyloxy group, first the derivatives of 4-hydroxyazobenzene dyes are prepared by the usual azo-coupling reaction of 2,6-dimethylphenol with substituted aryldiazonium salts, and then their acryloyloxy derivatives are synthesized in a Schottene–Bauman-type reaction similar to the following procedure and by the method described previously (Kocaokutgen et al., 2005). To a stirred tetrahydrofuran (20 ml) solution of substituted 4-hydroxyazobenzene dye (2.48 mmol) and sodium metal (2.48 mmol), acryloyl chloride (2.48 mmol) were directly added dropwise in an atmosphere of dry nitrogen. After 2 h of stirring, the mixture was filtered and the desired product was precipitated out by adding water. The solid was filtered off, washed several times with water and then dried. The products were crystallized from an ethanol/water mixture to give related compounds. The products were crystallized from dimethyl sulfoxide to produce crystals of suitable quality for X-ray difraction analysis.

S3. Refinement

Crystals of (II) gave a low mean data intensity, so the proportion of the data labelled `observed' is rather low (49%). In both compounds, all H atoms attached to C atoms were refined using a riding model [C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for aromatic H atoms, and C—H = 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl H atoms], except for atom H10 in compound (II), which was located from a difference map after the other H atoms were refined using a riding model.

Computing details

For both compounds, data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. : An ORTEP-3 (Farrugia, 1997) view of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.
	Fig. 2. : An ORTEP-3 (Farrugia, 1997) view of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.
	Fig. 3. : A packing diagram for (I), showing molecules linked by π–π and π-ring interactions between the aromatic rings of the azo compound.
	Fig. 4. : A packing diagram for (II), showing molecules linked by π–π and π-ring interactions between the aromatic rings of the azo compound.

(I) (E)-4-(4-bromophenyldiazenyl)-2,6-dimethylphenyl acrylate

Crystal data

C17H15BrN2O2	Z = 2
Mr = 359.21	F(000) = 364
Triclinic, P1	Dx = 1.443 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.2168 (10) Å	Cell parameters from 1578 reflections
b = 9.7823 (10) Å	θ = 1.9–25.1°
c = 14.0973 (7) Å	µ = 2.49 mm^−1
α = 98.977 (3)°	T = 297 K
β = 101.160 (2)°	Prism, orange
γ = 93.697 (7)°	0.4 × 0.3 × 0.2 mm
V = 826.83 (16) Å^3

Data collection

STOE IPDS-2 diffractometer	3931 independent reflections
Radiation source: fine-focus sealed tube	2667 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
Detector resolution: 6.67 pixels mm^-1	θmax = 27.9°, θmin = 2.1°
ω scans	h = −8→7
Absorption correction: integration X-RED32 (Stoe & Cie, 2002)	k = −12→12
Tmin = 0.975, Tmax = 0.987	l = −18→18
14480 measured 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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0493P)^2 + 0.2083P] where P = (Fo^2 + 2Fc^2)/3
3931 reflections	(Δ/σ)max < 0.001
201 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.41 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
C1	0.4818 (4)	0.0587 (3)	0.28362 (19)	0.0541 (6)
C2	0.5385 (4)	0.0053 (3)	0.1958 (2)	0.0588 (6)
H2	0.4523	−0.0701	0.1545	0.071*
C3	0.7219 (4)	0.0631 (3)	0.1690 (2)	0.0603 (6)
C4	0.8443 (4)	0.1764 (3)	0.2336 (2)	0.0575 (6)
C5	0.7935 (4)	0.2320 (3)	0.3219 (2)	0.0573 (6)
C6	0.6083 (4)	0.1715 (3)	0.3457 (2)	0.0573 (6)
H6	0.5681	0.2070	0.4042	0.069*
C7	0.9386 (5)	0.3508 (3)	0.3909 (2)	0.0773 (9)
H7A	1.0861	0.3252	0.4067	0.116*
H7B	0.8829	0.3713	0.4500	0.116*
H7C	0.9390	0.4316	0.3600	0.116*
C8	0.7915 (5)	0.0026 (4)	0.0766 (2)	0.0813 (9)
H8A	0.6961	−0.0797	0.0452	0.122*
H8B	0.9404	−0.0207	0.0922	0.122*
H8C	0.7826	0.0694	0.0332	0.122*
C9	1.0380 (5)	0.3145 (3)	0.1479 (2)	0.0660 (7)
C10	1.2619 (6)	0.3389 (4)	0.1273 (3)	0.0808 (9)
H10	1.3780	0.3008	0.1628	0.097*
C11	1.3009 (7)	0.4093 (5)	0.0634 (3)	0.1158 (15)
H11A	1.1871	0.4483	0.0270	0.139*
H11B	1.4434	0.4220	0.0529	0.139*
C12	0.0179 (4)	−0.1648 (3)	0.29502 (19)	0.0569 (6)
C13	−0.0854 (5)	−0.2872 (3)	0.2380 (2)	0.0746 (8)
H13	−0.0381	−0.3231	0.1813	0.090*
C14	−0.2589 (5)	−0.3571 (3)	0.2642 (2)	0.0775 (9)
H14	−0.3278	−0.4403	0.2260	0.093*
C15	−0.3275 (4)	−0.3024 (3)	0.3470 (2)	0.0621 (7)
C16	−0.2303 (5)	−0.1789 (3)	0.4039 (2)	0.0668 (7)
H16	−0.2813	−0.1421	0.4594	0.080*
C17	−0.0556 (5)	−0.1099 (3)	0.3776 (2)	0.0634 (7)
H17	0.0122	−0.0264	0.4157	0.076*
N2	0.1971 (4)	−0.1040 (2)	0.26148 (17)	0.0618 (6)
N1	0.3006 (3)	0.0010 (2)	0.31815 (16)	0.0579 (5)
O1	1.0427 (3)	0.2272 (2)	0.21223 (15)	0.0696 (5)
O2	0.8742 (4)	0.3615 (3)	0.11343 (19)	0.0906 (7)
Br1	−0.56024 (5)	−0.40066 (4)	0.38566 (3)	0.08644 (16)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0475 (12)	0.0578 (14)	0.0608 (15)	−0.0005 (11)	0.0188 (11)	0.0141 (11)
C2	0.0515 (13)	0.0651 (15)	0.0595 (15)	−0.0030 (12)	0.0159 (11)	0.0077 (12)
C3	0.0543 (13)	0.0727 (16)	0.0590 (15)	0.0025 (12)	0.0221 (11)	0.0152 (12)
C4	0.0442 (12)	0.0660 (15)	0.0699 (16)	0.0031 (11)	0.0209 (11)	0.0238 (13)
C5	0.0513 (13)	0.0550 (14)	0.0678 (16)	0.0000 (11)	0.0164 (12)	0.0144 (12)
C6	0.0548 (13)	0.0584 (14)	0.0618 (15)	−0.0006 (11)	0.0224 (11)	0.0093 (12)
C7	0.0679 (17)	0.0718 (18)	0.088 (2)	−0.0163 (15)	0.0176 (15)	0.0073 (16)
C8	0.0730 (18)	0.105 (2)	0.0699 (19)	−0.0011 (18)	0.0320 (15)	0.0087 (17)
C9	0.0669 (17)	0.0674 (17)	0.0669 (17)	−0.0038 (14)	0.0223 (14)	0.0152 (14)
C10	0.0801 (19)	0.082 (2)	0.083 (2)	−0.0169 (16)	0.0316 (16)	0.0155 (16)
C11	0.089 (2)	0.149 (4)	0.120 (3)	−0.018 (3)	0.038 (2)	0.050 (3)
C12	0.0503 (13)	0.0567 (14)	0.0640 (15)	−0.0047 (11)	0.0153 (11)	0.0115 (12)
C13	0.0744 (18)	0.0730 (18)	0.0745 (19)	−0.0162 (15)	0.0287 (15)	−0.0005 (15)
C14	0.0707 (18)	0.0680 (17)	0.087 (2)	−0.0228 (15)	0.0201 (16)	−0.0004 (15)
C15	0.0536 (13)	0.0636 (15)	0.0726 (17)	−0.0057 (12)	0.0186 (12)	0.0201 (13)
C16	0.0657 (16)	0.0690 (17)	0.0686 (17)	−0.0079 (14)	0.0264 (13)	0.0113 (14)
C17	0.0619 (14)	0.0630 (15)	0.0642 (16)	−0.0115 (12)	0.0211 (12)	0.0050 (13)
N2	0.0565 (12)	0.0657 (13)	0.0651 (13)	−0.0063 (10)	0.0221 (10)	0.0102 (10)
N1	0.0525 (11)	0.0589 (12)	0.0635 (13)	−0.0078 (10)	0.0201 (10)	0.0093 (10)
O1	0.0486 (9)	0.0850 (13)	0.0852 (13)	−0.0002 (9)	0.0261 (9)	0.0326 (11)
O2	0.0823 (15)	0.0970 (17)	0.1064 (18)	0.0075 (13)	0.0275 (13)	0.0499 (14)
Br1	0.0725 (2)	0.0857 (2)	0.1061 (3)	−0.02050 (16)	0.03389 (17)	0.02399 (18)

Geometric parameters (Å, º)

C1—C2	1.385 (4)	C9—O1	1.337 (4)
C1—C6	1.387 (3)	C9—C10	1.488 (4)
C1—N1	1.428 (3)	C10—C11	1.264 (5)
C2—C3	1.383 (3)	C10—H10	0.9300
C2—H2	0.9300	C11—H11A	0.9300
C3—C4	1.394 (4)	C11—H11B	0.9300
C3—C8	1.499 (4)	C12—C13	1.376 (4)
C4—C5	1.381 (4)	C12—C17	1.377 (4)
C4—O1	1.404 (3)	C12—N2	1.423 (3)
C5—C6	1.383 (3)	C13—C14	1.381 (4)
C5—C7	1.511 (4)	C13—H13	0.9300
C6—H6	0.9300	C14—C15	1.363 (4)
C7—H7A	0.9600	C14—H14	0.9300
C7—H7B	0.9600	C15—C16	1.372 (4)
C7—H7C	0.9600	C15—Br1	1.899 (2)
C8—H8A	0.9600	C16—C17	1.383 (3)
C8—H8B	0.9600	C16—H16	0.9300
C8—H8C	0.9600	C17—H17	0.9300
C9—O2	1.193 (4)	N2—N1	1.252 (3)
C2—C1—C6	120.2 (2)	O2—C9—O1	123.0 (3)
C2—C1—N1	123.9 (2)	O2—C9—C10	127.5 (3)
C6—C1—N1	115.8 (2)	O1—C9—C10	109.6 (3)
C3—C2—C1	120.7 (2)	C11—C10—C9	122.8 (4)
C3—C2—H2	119.7	C11—C10—H10	118.6
C1—C2—H2	119.7	C9—C10—H10	118.6
C2—C3—C4	117.1 (2)	C10—C11—H11A	120.0
C2—C3—C8	121.3 (3)	C10—C11—H11B	120.0
C4—C3—C8	121.5 (2)	H11A—C11—H11B	120.0
C5—C4—C3	123.8 (2)	C13—C12—C17	119.7 (2)
C5—C4—O1	118.1 (2)	C13—C12—N2	115.3 (2)
C3—C4—O1	117.7 (2)	C17—C12—N2	125.0 (2)
C4—C5—C6	117.2 (2)	C12—C13—C14	120.5 (3)
C4—C5—C7	121.3 (2)	C12—C13—H13	119.7
C6—C5—C7	121.5 (3)	C14—C13—H13	119.7
C5—C6—C1	120.9 (2)	C15—C14—C13	119.0 (3)
C5—C6—H6	119.5	C15—C14—H14	120.5
C1—C6—H6	119.5	C13—C14—H14	120.5
C5—C7—H7A	109.5	C14—C15—C16	121.6 (2)
C5—C7—H7B	109.5	C14—C15—Br1	119.2 (2)
H7A—C7—H7B	109.5	C16—C15—Br1	119.2 (2)
C5—C7—H7C	109.5	C15—C16—C17	119.1 (3)
H7A—C7—H7C	109.5	C15—C16—H16	120.4
H7B—C7—H7C	109.5	C17—C16—H16	120.4
C3—C8—H8A	109.5	C12—C17—C16	120.0 (2)
C3—C8—H8B	109.5	C12—C17—H17	120.0
H8A—C8—H8B	109.5	C16—C17—H17	120.0
C3—C8—H8C	109.5	N1—N2—C12	114.5 (2)
H8A—C8—H8C	109.5	N2—N1—C1	113.4 (2)
H8B—C8—H8C	109.5	C9—O1—C4	119.4 (2)
C6—C1—C2—C3	0.3 (4)	N2—C12—C13—C14	178.8 (3)
N1—C1—C2—C3	−177.3 (3)	C12—C13—C14—C15	0.6 (5)
C1—C2—C3—C4	−0.3 (4)	C13—C14—C15—C16	0.9 (5)
C1—C2—C3—C8	177.1 (3)	C13—C14—C15—Br1	−178.2 (3)
C2—C3—C4—C5	0.6 (4)	C14—C15—C16—C17	−1.3 (5)
C8—C3—C4—C5	−176.8 (3)	Br1—C15—C16—C17	177.7 (2)
C2—C3—C4—O1	173.7 (2)	C13—C12—C17—C16	1.1 (5)
C8—C3—C4—O1	−3.6 (4)	N2—C12—C17—C16	−179.3 (3)
C3—C4—C5—C6	−0.8 (4)	C15—C16—C17—C12	0.3 (5)
O1—C4—C5—C6	−173.9 (2)	C13—C12—N2—N1	−174.5 (3)
C3—C4—C5—C7	177.2 (3)	C17—C12—N2—N1	5.9 (4)
O1—C4—C5—C7	4.0 (4)	C12—N2—N1—C1	179.0 (2)
C4—C5—C6—C1	0.7 (4)	C2—C1—N1—N2	0.5 (4)
C7—C5—C6—C1	−177.2 (3)	C6—C1—N1—N2	−177.2 (2)
C2—C1—C6—C5	−0.5 (4)	O2—C9—O1—C4	6.6 (4)
N1—C1—C6—C5	177.2 (2)	C10—C9—O1—C4	−172.5 (2)
O2—C9—C10—C11	−4.4 (6)	C5—C4—O1—C9	−104.1 (3)
O1—C9—C10—C11	174.6 (4)	C3—C4—O1—C9	82.3 (3)
C17—C12—C13—C14	−1.6 (5)

(II) (E)-2,6-dimethyl-4-(4-methylphenyldiazenyl)phenyl acrylate

Crystal data

C18H18N2O2	Z = 2
Mr = 294.34	F(000) = 312
Triclinic, P1	Dx = 1.171 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.1589 (8) Å	Cell parameters from 1385 reflections
b = 11.2603 (15) Å	θ = 2.8–27.6°
c = 12.3461 (16) Å	µ = 0.08 mm^−1
α = 82.780 (11)°	T = 297 K
β = 80.070 (11)°	Prism, orange
γ = 85.321 (11)°	0.23 × 0.21 × 0.16 mm
V = 835.13 (19) Å^3

Data collection

STOE IPDS-2 diffractometer	3298 independent reflections
Radiation source: fine-focus sealed tube	1615 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.144
Detector resolution: 6.67 pixels mm^-1	θmax = 26.0°, θmin = 2.3°
ω scans	h = −7→7
Absorption correction: integration X-RED32 (Stoe & Cie, 2002)	k = −13→13
Tmin = 0.980, Tmax = 0.985	l = −15→15
10895 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.084	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.216	w = 1/[σ^2(Fo^2) + (0.0544P)^2 + 0.315P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
3298 reflections	Δρmax = 0.13 e Å^−3
206 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.018 (5)

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
C1	0.3100 (5)	0.2166 (4)	0.2333 (3)	0.0657 (10)
C2	0.3576 (6)	0.3300 (4)	0.2507 (3)	0.0737 (11)
H2	0.2788	0.3970	0.2218	0.088*
C3	0.5225 (6)	0.3445 (4)	0.3112 (3)	0.0717 (11)
C4	0.6375 (5)	0.2413 (4)	0.3502 (3)	0.0658 (10)
C5	0.5950 (6)	0.1274 (4)	0.3356 (3)	0.0689 (10)
C6	0.4257 (6)	0.1172 (4)	0.2757 (3)	0.0732 (11)
H6	0.3905	0.0414	0.2644	0.088*
C7	0.5839 (9)	0.4655 (4)	0.3277 (4)	0.1147 (19)
H7A	0.5733	0.4711	0.4054	0.172*
H7B	0.4852	0.5258	0.2969	0.172*
H7C	0.7326	0.4777	0.2914	0.172*
C8	0.7305 (7)	0.0185 (4)	0.3765 (4)	0.0989 (15)
H8A	0.8760	0.0177	0.3334	0.148*
H8B	0.6611	−0.0527	0.3693	0.148*
H8C	0.7407	0.0213	0.4528	0.148*
C12	−0.1025 (6)	0.2579 (4)	0.0598 (3)	0.0680 (10)
C13	−0.2171 (7)	0.3575 (4)	0.0150 (3)	0.0858 (13)
H13	−0.1907	0.4342	0.0282	0.103*
C14	−0.3732 (7)	0.3408 (4)	−0.0505 (3)	0.0826 (12)
H14	−0.4506	0.4076	−0.0806	0.099*
C15	−0.4163 (6)	0.2292 (4)	−0.0718 (3)	0.0696 (11)
C16	−0.2977 (6)	0.1325 (4)	−0.0265 (3)	0.0790 (12)
H16	−0.3216	0.0559	−0.0409	0.095*
C17	−0.1439 (6)	0.1458 (4)	0.0399 (3)	0.0769 (11)
H17	−0.0686	0.0786	0.0709	0.092*
C18	−0.5889 (6)	0.2139 (5)	−0.1422 (3)	0.0916 (14)
H18A	−0.5217	0.2191	−0.2187	0.137*
H18B	−0.7047	0.2759	−0.1323	0.137*
H18C	−0.6494	0.1370	−0.1203	0.137*
C9	0.7864 (7)	0.2610 (4)	0.5110 (3)	0.0741 (11)
C10	0.9968 (8)	0.2759 (5)	0.5478 (4)	0.0929 (16)
C11	1.0081 (9)	0.2886 (5)	0.6475 (5)	0.122 (2)
H11A	0.8806	0.2886	0.7003	0.146*
H11B	1.1440	0.2978	0.6677	0.146*
N1	0.1474 (5)	0.1919 (3)	0.1691 (3)	0.0730 (9)
N2	0.0549 (5)	0.2839 (3)	0.1267 (3)	0.0741 (9)
O1	0.8204 (4)	0.2556 (3)	0.4017 (2)	0.0781 (8)
O2	0.6091 (5)	0.2529 (3)	0.5670 (2)	0.1019 (11)
H10	1.122 (8)	0.300 (5)	0.511 (4)	0.122*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0543 (19)	0.091 (3)	0.056 (2)	−0.011 (2)	−0.0129 (16)	−0.016 (2)
C2	0.070 (2)	0.093 (3)	0.063 (2)	−0.002 (2)	−0.0251 (18)	−0.011 (2)
C3	0.078 (2)	0.078 (3)	0.064 (2)	−0.008 (2)	−0.0182 (19)	−0.014 (2)
C4	0.055 (2)	0.091 (3)	0.055 (2)	−0.014 (2)	−0.0162 (16)	−0.007 (2)
C5	0.059 (2)	0.084 (3)	0.065 (2)	−0.005 (2)	−0.0148 (17)	−0.006 (2)
C6	0.065 (2)	0.083 (3)	0.077 (3)	−0.009 (2)	−0.0183 (19)	−0.019 (2)
C7	0.152 (5)	0.088 (4)	0.127 (4)	−0.015 (3)	−0.079 (4)	−0.014 (3)
C8	0.084 (3)	0.099 (4)	0.119 (4)	0.005 (3)	−0.037 (3)	−0.013 (3)
C12	0.054 (2)	0.094 (3)	0.059 (2)	−0.003 (2)	−0.0126 (16)	−0.016 (2)
C13	0.084 (3)	0.100 (4)	0.084 (3)	0.007 (3)	−0.034 (2)	−0.026 (3)
C14	0.079 (3)	0.098 (4)	0.074 (3)	0.012 (2)	−0.028 (2)	−0.013 (2)
C15	0.059 (2)	0.098 (3)	0.054 (2)	−0.010 (2)	−0.0120 (16)	−0.008 (2)
C16	0.073 (2)	0.094 (3)	0.076 (3)	−0.018 (2)	−0.028 (2)	−0.005 (2)
C17	0.069 (2)	0.085 (3)	0.080 (3)	−0.005 (2)	−0.025 (2)	−0.006 (2)
C18	0.076 (3)	0.131 (4)	0.075 (3)	−0.019 (3)	−0.031 (2)	−0.007 (3)
C9	0.077 (3)	0.084 (3)	0.067 (2)	−0.009 (2)	−0.024 (2)	−0.009 (2)
C10	0.104 (3)	0.102 (4)	0.088 (3)	−0.017 (3)	−0.059 (3)	−0.003 (3)
C11	0.103 (4)	0.162 (6)	0.117 (4)	−0.010 (4)	−0.052 (3)	−0.025 (4)
N1	0.0617 (18)	0.091 (3)	0.0691 (19)	−0.0069 (17)	−0.0175 (15)	−0.0099 (18)
N2	0.0606 (18)	0.096 (3)	0.070 (2)	−0.0003 (18)	−0.0196 (16)	−0.0179 (19)
O1	0.0604 (15)	0.115 (2)	0.0652 (16)	−0.0124 (15)	−0.0219 (12)	−0.0137 (15)
O2	0.083 (2)	0.168 (3)	0.0619 (17)	−0.023 (2)	−0.0165 (15)	−0.0231 (19)

Geometric parameters (Å, º)

C1—C6	1.373 (5)	C13—C14	1.396 (5)
C1—C2	1.384 (5)	C13—H13	0.9300
C1—N1	1.443 (4)	C14—C15	1.372 (6)
C2—C3	1.391 (5)	C14—H14	0.9300
C2—H2	0.9300	C15—C16	1.374 (5)
C3—C4	1.388 (5)	C15—C18	1.517 (5)
C3—C7	1.490 (6)	C16—C17	1.383 (5)
C4—C5	1.369 (5)	C16—H16	0.9300
C4—O1	1.414 (4)	C17—H17	0.9300
C5—C6	1.398 (5)	C18—H18A	0.9600
C5—C8	1.509 (5)	C18—H18B	0.9600
C6—H6	0.9300	C18—H18C	0.9600
C7—H7A	0.9600	C9—O2	1.191 (5)
C7—H7B	0.9600	C9—O1	1.338 (4)
C7—H7C	0.9600	C9—C10	1.474 (5)
C8—H8A	0.9600	C10—C11	1.270 (6)
C8—H8B	0.9600	C10—H10	0.87 (5)
C8—H8C	0.9600	C11—H11A	0.9300
C12—C17	1.368 (6)	C11—H11B	0.9300
C12—C13	1.383 (5)	N1—N2	1.241 (4)
C12—N2	1.446 (4)
C6—C1—C2	120.1 (3)	C12—C13—C14	118.6 (4)
C6—C1—N1	115.0 (4)	C12—C13—H13	120.7
C2—C1—N1	124.9 (4)	C14—C13—H13	120.7
C1—C2—C3	120.5 (4)	C15—C14—C13	122.3 (4)
C1—C2—H2	119.8	C15—C14—H14	118.9
C3—C2—H2	119.8	C13—C14—H14	118.9
C4—C3—C2	117.1 (4)	C14—C15—C16	117.3 (3)
C4—C3—C7	121.0 (3)	C14—C15—C18	121.0 (4)
C2—C3—C7	121.8 (4)	C16—C15—C18	121.7 (4)
C5—C4—C3	124.4 (3)	C15—C16—C17	121.9 (4)
C5—C4—O1	117.9 (4)	C15—C16—H16	119.0
C3—C4—O1	117.5 (4)	C17—C16—H16	119.0
C4—C5—C6	116.5 (4)	C12—C17—C16	119.9 (4)
C4—C5—C8	122.1 (3)	C12—C17—H17	120.0
C6—C5—C8	121.3 (4)	C16—C17—H17	120.0
C1—C6—C5	121.5 (4)	C15—C18—H18A	109.5
C1—C6—H6	119.3	C15—C18—H18B	109.5
C5—C6—H6	119.3	H18A—C18—H18B	109.5
C3—C7—H7A	109.5	C15—C18—H18C	109.5
C3—C7—H7B	109.5	H18A—C18—H18C	109.5
H7A—C7—H7B	109.5	H18B—C18—H18C	109.5
C3—C7—H7C	109.5	O2—C9—O1	122.8 (3)
H7A—C7—H7C	109.5	O2—C9—C10	127.2 (4)
H7B—C7—H7C	109.5	O1—C9—C10	110.0 (4)
C5—C8—H8A	109.5	C11—C10—C9	122.4 (5)
C5—C8—H8B	109.5	C11—C10—H10	104 (4)
H8A—C8—H8B	109.5	C9—C10—H10	131 (4)
C5—C8—H8C	109.5	C10—C11—H11A	120.0
H8A—C8—H8C	109.5	C10—C11—H11B	120.0
H8B—C8—H8C	109.5	H11A—C11—H11B	120.0
C17—C12—C13	119.9 (3)	N2—N1—C1	113.3 (4)
C17—C12—N2	125.4 (4)	N1—N2—C12	112.7 (4)
C13—C12—N2	114.7 (4)	C9—O1—C4	118.6 (3)
C6—C1—C2—C3	0.0 (6)	C13—C14—C15—C16	−0.5 (6)
N1—C1—C2—C3	−178.0 (4)	C13—C14—C15—C18	179.3 (4)
C1—C2—C3—C4	1.3 (6)	C14—C15—C16—C17	1.3 (6)
C1—C2—C3—C7	177.6 (4)	C18—C15—C16—C17	−178.5 (4)
C2—C3—C4—C5	−1.9 (6)	C13—C12—C17—C16	1.0 (6)
C7—C3—C4—C5	−178.1 (4)	N2—C12—C17—C16	−179.5 (4)
C2—C3—C4—O1	173.6 (3)	C15—C16—C17—C12	−1.6 (6)
C7—C3—C4—O1	−2.7 (6)	O2—C9—C10—C11	−4.0 (9)
C3—C4—C5—C6	1.0 (6)	O1—C9—C10—C11	177.0 (5)
O1—C4—C5—C6	−174.4 (3)	C6—C1—N1—N2	−176.1 (3)
C3—C4—C5—C8	177.8 (4)	C2—C1—N1—N2	2.0 (5)
O1—C4—C5—C8	2.5 (6)	C1—N1—N2—C12	178.2 (3)
C2—C1—C6—C5	−1.0 (6)	C17—C12—N2—N1	−2.4 (5)
N1—C1—C6—C5	177.2 (3)	C13—C12—N2—N1	177.2 (4)
C4—C5—C6—C1	0.5 (6)	O2—C9—O1—C4	0.9 (6)
C8—C5—C6—C1	−176.4 (4)	C10—C9—O1—C4	180.0 (4)
C17—C12—C13—C14	−0.2 (6)	C5—C4—O1—C9	−94.4 (4)
N2—C12—C13—C14	−179.8 (4)	C3—C4—O1—C9	89.9 (4)
C12—C13—C14—C15	−0.1 (6)