2-(Naphthalen-2-yl)azulene

Ye, J.; Shi, Z.-F.; Sun, C.-L.; Xu, Z.-G.; Zhang, H.-L.

doi:10.1107/S1600536810004897

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 66| Part 3| March 2010| Pages o592-o593

doi:10.1107/S1600536810004897

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2-(Naphthalen-2-yl)azulene

Jian Ye,^a Zi-Fa Shi,^a Chun-Lin Sun,^a Zhu-Guo Xu ^a ^* and Hao-Li Zhang ^a

^aState Key Laboratory of Applied Organic Chemistry and College of Chemistry and, Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
^*Correspondence e-mail: xuzhg@lzu.edu.cn

(Received 3 February 2010; accepted 8 February 2010; online 13 February 2010)

In the title compound, C₂₀H₁₄, a naphthalene ring system is linked at the 2-position to the 2-C atom of the five-membered ring of an azulene unit. The compound crystallizes with two reasonably similar molecules in the asymmetric unit. Neither molecule is perfectly planar: the r.m.s. deviations from the best fit planes through all non-H atoms are 0.092 and 0.091 Å for the two molecules. The dihedral angle between the molecular planes is 49.60 (4)°. The naphthalene and azulene ring systems are inclined at dihedral angles of 6.54 (12) and 5.68 (12)° in the two molecules. The crystal structure exhibits two sets of parallel layers, a typical edge-to-face herringbone packing arrangement. The structure is stabilized by an extensive series of weak C—H⋯π interactions.

Related literature

For the structure and properties of azulene, see: Zhang & Petoud (2008 ); Dewar (1969 ); Wang et al. (1999 ). For applications of azulene derivatives, see: Ito et al. (2005 ); Lambert et al. (2003 ); Porsch et al. (1997 ); Schmitt et al. (1998 ). For the crystal structures of some organic semiconductors, see: Tan et al. (2009 ); Ando et al. (2005 ).

Experimental

Crystal data

C₂₀H₁₄
M_r = 254.31
Triclinic, P 1
a = 6.0754 (8) Å
b = 7.6324 (11) Å
c = 14.5662 (19) Å
α = 97.997 (7)°
β = 97.179 (6)°
γ = 90.526 (7)°
V = 663.38 (16) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 K
0.35 × 0.32 × 0.13 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1997 ) T_min = 0.975, T_max = 0.991
3762 measured reflections
2573 independent reflections
2039 reflections with I > 2σ(I)
R_int = 0.021

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.130
S = 1.04
2573 reflections
361 parameters
3 restraints
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg1, Cg4, Cg5, Cg6, Cg7 and Cg8 are the centroids of the C1–C3/C8–C10, C13–C19, C1′–C2′/C7′–C10′, C2′–C7′, C11′–C13′/C19′,C20′ and C13′–C19′ rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯Cg5ⁱ	0.93	2.84	3.488 (4)	128
C7—H7⋯Cg6ⁱⁱ	0.93	2.81	3.544 (4)	137
C8′—H8′⋯Cg1ⁱⁱⁱ	0.93	2.82	3.456 (4)	126
C14—H14⋯Cg7ⁱⁱ	0.93	2.75	3.430 (4)	131
C14′—H14′⋯Cg4ⁱⁱⁱ	0.93	2.77	3.485 (4)	135
C18—H18⋯Cg8ⁱ	0.93	2.73	3.446 (4)	134
C18′—H18′⋯Cg4	0.93	2.79	3.463 (4)	130
Symmetry codes: (i) x, y-1, z; (ii) x-1, y, z; (iii) x+1, y+1, z.

Data collection: SMART (Bruker 1997); cell refinement: SAINT (Bruker 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S1600536810004897/sj2726sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810004897/sj2726Isup2.hkl

checkCIF report

Comment top

Azulene, whose structure consists of a cyclopentadiene ring fused with a cycloheptatriene ring, is an isomer of naphthalene. However its photophysical properties differ significantly from those of naphthalene. Because of its particular electronic structure, azulene is a versatile organic fragment with both an electron-rich five-membered ring and an electron-deficient seven-membered ring (Zhang & Petoud, 2008). The calculations resulting from various aromaticity theories indicate that azulene possesses much lower aromatic delocalization energy (e.g., 4.2 kcal/mol) (Dewar, 1969, Wang et al., 1999) compared to benzene, thiophene, and naphthalene. Due to this special character, azulene and its derivatives have attracted a growing interest in various areas of molecular materials, such as charge transfer complexes (Schmitt et al., 1998), conducting polymers (Porsch et al., 1997), liquid crystals (Ito et al., 2005), as well as nonlinear optical (NLO) materials (Lambert et al., 2003). This report on the crystal structure 2-(naphthalen-2-yl)azulene (I), is a preliminary report of our work on the synthesis and analysis of azulene-containing molecular devices.

Compound I crystallizes with two discrete molecules in the asymmetric unit of the triclinic unit cell (space group P1). The torsion angle between azulene and naphthalene plane is 6.54 (12)° for one and 5.68 (12) ° for the other. The crystal packing of compound I can be classified as an edge-to-face herringbone-type geometry, and the tilt angle between two molecular planes is 49.60 (4)°. Such packing is similar to that of some organic semiconductors with oligomers (Tan et al., 2009, Ando et al., 2005).The crystal packing exhibits weak C—H···π interactions (Table 1). Cg1, Cg4, Cg5, Cg6, Cg7 and Cg8 are centroids of the C1—C2—C3—C8—C9—C10, C13—C19, C1'-C2'-C7'-C8'-C9'-C10', C2'—C7', C11'-C12'-C13'-C19'-C20' and C13'—C19' rings respectively.

Related literature top

For the structure and properties of azulene, see: Zhang & Petoud (2008); Dewar (1969); Wang et al. (1999). For applications of azulene derivatives, see: Ito et al. (2005); Lambert et al. (2003); Porsch et al. (1997); Schmitt et al. (1998). For the crystal structures of some organic semiconductors, see: Tan et al. (2009); Ando et al. (2005).

Experimental top

To a mixture of azulen-2-yl trifluoromethanesulfonate (138 mg, 0.50 mmol) in THF (10 ml) were added 2-naphthalenylboronic acid (172 mg, 1.00 mmol), Pd(PPh₃)₄ (23 mg, 0.02 mmol) and Cs₂CO₃ saturated aqueous (1.0 ml). The mixture was refluxed overnight. The reaction was quenched with water, and extracted with ether (3 x 20 ml). Organic layers were washed with brine, dried (MgSO₄), filtered, concentrated in vacuo and purified by flash chromatography (petroleum ether/CH₂Cl₂, 5:1) to provide the title compound as a dark-blue solid: mp 274–276 °C. Dark-blue crystalline blocks were obtained by slow evaporation of chloroform.

Computing details top

Data collection: SMART (Bruker 1997); cell refinement: SAINT (Bruker 1997); data reduction: SAINT (Bruker 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008.

Figures top

	Fig. 1. The asymmetric unit of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 30% probability level.
	Fig. 2. Crystal packing for (I) viewed down the a axis.

2-(naphthalen-2-yl)azulene top

Crystal data top

C₂₀H₁₄	Z = 2
M_r = 254.31	F(000) = 268
Triclinic, P1	D_x = 1.273 Mg m⁻³
Hall symbol: P 1	Melting point = 547–549 K
a = 6.0754 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.6324 (11) Å	Cell parameters from 1303 reflections
c = 14.5662 (19) Å	θ = 2.9–24.7°
α = 97.997 (7)°	µ = 0.07 mm⁻¹
β = 97.179 (6)°	T = 293 K
γ = 90.526 (7)°	Block, blue
V = 663.38 (16) Å³	0.35 × 0.32 × 0.13 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	2573 independent reflections
Radiation source: fine-focus sealed tube	2039 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.021
ϕ and ω scans	θ_max = 26.0°, θ_min = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −7→7
T_min = 0.975, T_max = 0.991	k = −9→8
3762 measured reflections	l = −17→16

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.130	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0764P)²] where P = (F_o² + 2F_c²)/3
2573 reflections	(Δ/σ)_max < 0.001
361 parameters	Δρ_max = 0.16 e Å⁻³
3 restraints	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₂₀H₁₄	γ = 90.526 (7)°
M_r = 254.31	V = 663.38 (16) Å³
Triclinic, P1	Z = 2
a = 6.0754 (8) Å	Mo Kα radiation
b = 7.6324 (11) Å	µ = 0.07 mm⁻¹
c = 14.5662 (19) Å	T = 293 K
α = 97.997 (7)°	0.35 × 0.32 × 0.13 mm
β = 97.179 (6)°

Data collection top

Bruker SMART CCD area-detector diffractometer	2573 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1997)	2039 reflections with I > 2σ(I)
T_min = 0.975, T_max = 0.991	R_int = 0.021
3762 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	3 restraints
wR(F²) = 0.130	H-atom parameters constrained
S = 1.04	Δρ_max = 0.16 e Å⁻³
2573 reflections	Δρ_min = −0.16 e Å⁻³
361 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.3852 (6)	0.1216 (5)	0.5454 (3)	0.0531 (10)
H1	0.4727	0.0839	0.4988	0.064*
C2	0.4630 (7)	0.1084 (5)	0.6353 (3)	0.0576 (11)
H2	0.6020	0.0617	0.6493	0.069*
C3	0.3356 (7)	0.1650 (5)	0.7080 (3)	0.0526 (10)
C4	0.4094 (7)	0.1490 (6)	0.8036 (3)	0.0630 (12)
H4	0.5453	0.0992	0.8199	0.076*
C5	0.2791 (9)	0.2075 (7)	0.8705 (3)	0.0711 (13)
H5	0.3277	0.1972	0.9326	0.085*
C6	0.0742 (8)	0.2825 (6)	0.8480 (3)	0.0653 (12)
H6	−0.0116	0.3220	0.8949	0.078*
C7	0.0002 (7)	0.2978 (5)	0.7577 (3)	0.0545 (10)
H7	−0.1365	0.3482	0.7437	0.065*
C8	0.1255 (6)	0.2393 (5)	0.6846 (3)	0.0471 (9)
C9	0.0509 (6)	0.2508 (5)	0.5908 (3)	0.0480 (9)
H9	−0.0859	0.3003	0.5759	0.058*
C10	0.1729 (6)	0.1915 (4)	0.5200 (2)	0.0428 (9)
C11	0.0910 (6)	0.1919 (5)	0.4208 (3)	0.0436 (9)
C12	−0.1122 (6)	0.2601 (5)	0.3858 (3)	0.0479 (9)
H12	−0.2134	0.3157	0.4223	0.057*
C13	−0.1395 (6)	0.2324 (4)	0.2889 (3)	0.0443 (9)
C14	−0.3185 (6)	0.2829 (5)	0.2301 (3)	0.0496 (9)
H14	−0.4308	0.3389	0.2599	0.060*
C15	−0.3528 (7)	0.2615 (6)	0.1338 (3)	0.0574 (11)
H15	−0.4841	0.3057	0.1072	0.069*
C16	−0.2149 (7)	0.1818 (6)	0.0712 (3)	0.0584 (11)
H16	−0.2676	0.1809	0.0084	0.070*
C17	−0.0131 (7)	0.1044 (6)	0.0883 (3)	0.0591 (11)
H17	0.0498	0.0587	0.0354	0.071*
C18	0.1091 (7)	0.0848 (5)	0.1718 (3)	0.0540 (10)
H18	0.2418	0.0263	0.1675	0.065*
C19	0.0620 (6)	0.1398 (5)	0.2616 (3)	0.0470 (9)
C20	0.1931 (6)	0.1178 (5)	0.3448 (3)	0.0500 (9)
H20	0.3286	0.0619	0.3488	0.060*
C1'	0.5370 (6)	0.6436 (5)	0.5553 (3)	0.0456 (9)
H1'	0.3975	0.5908	0.5352	0.055*
C2'	0.6193 (6)	0.6635 (4)	0.6506 (3)	0.0440 (9)
C3'	0.4909 (7)	0.6150 (5)	0.7189 (3)	0.0522 (10)
H3'	0.3505	0.5633	0.6997	0.063*
C4'	0.5691 (7)	0.6425 (6)	0.8116 (3)	0.0607 (11)
H4'	0.4830	0.6079	0.8548	0.073*
C5'	0.7779 (7)	0.7226 (6)	0.8422 (3)	0.0622 (11)
H5'	0.8277	0.7446	0.9059	0.075*
C6'	0.9095 (7)	0.7690 (5)	0.7797 (3)	0.0569 (10)
H6'	1.0496	0.8198	0.8008	0.068*
C7'	0.8332 (6)	0.7400 (5)	0.6821 (3)	0.0487 (9)
C8'	0.9599 (6)	0.7907 (5)	0.6147 (3)	0.0536 (10)
H8'	1.1029	0.8374	0.6333	0.064*
C9'	0.8756 (6)	0.7720 (5)	0.5237 (3)	0.0486 (9)
H9'	0.9626	0.8070	0.4809	0.058*
C10'	0.6590 (6)	0.7009 (4)	0.4907 (2)	0.0420 (8)
C11'	0.5689 (6)	0.6949 (4)	0.3917 (3)	0.0432 (9)
C12'	0.6771 (6)	0.7610 (5)	0.3238 (3)	0.0467 (9)
H12'	0.8171	0.8159	0.3342	0.056*
C13'	0.5428 (6)	0.7320 (5)	0.2383 (3)	0.0456 (9)
C14'	0.5962 (7)	0.7764 (5)	0.1547 (3)	0.0526 (10)
H14'	0.7334	0.8335	0.1577	0.063*
C15'	0.4729 (7)	0.7471 (6)	0.0676 (3)	0.0574 (11)
H15'	0.5391	0.7871	0.0198	0.069*
C16'	0.2669 (7)	0.6676 (6)	0.0410 (3)	0.0569 (10)
H16'	0.2159	0.6595	−0.0224	0.068*
C17'	0.1225 (7)	0.5972 (5)	0.0944 (3)	0.0549 (10)
H17'	−0.0119	0.5511	0.0620	0.066*
C18'	0.1523 (6)	0.5867 (5)	0.1894 (3)	0.0482 (9)
H18'	0.0357	0.5345	0.2124	0.058*
C19'	0.3336 (6)	0.6442 (4)	0.2542 (3)	0.0435 (8)
C20'	0.3596 (6)	0.6260 (5)	0.3491 (3)	0.0459 (9)
H20'	0.2543	0.5758	0.3795	0.055*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.047 (2)	0.048 (2)	0.063 (3)	0.0042 (18)	0.0056 (19)	0.0059 (19)
C2	0.049 (2)	0.047 (2)	0.075 (3)	0.0051 (19)	0.003 (2)	0.007 (2)
C3	0.048 (2)	0.041 (2)	0.066 (3)	−0.0037 (18)	0.0014 (19)	0.0053 (18)
C4	0.055 (3)	0.061 (3)	0.070 (3)	−0.003 (2)	−0.007 (2)	0.011 (2)
C5	0.075 (3)	0.085 (3)	0.049 (3)	−0.009 (3)	−0.008 (2)	0.010 (2)
C6	0.062 (3)	0.077 (3)	0.054 (3)	−0.005 (2)	0.010 (2)	−0.001 (2)
C7	0.049 (2)	0.055 (2)	0.057 (3)	0.0003 (19)	0.0057 (18)	−0.0010 (19)
C8	0.049 (2)	0.036 (2)	0.053 (2)	−0.0037 (17)	0.0015 (17)	0.0011 (17)
C9	0.044 (2)	0.041 (2)	0.059 (2)	0.0024 (17)	0.0063 (17)	0.0077 (17)
C10	0.0410 (19)	0.0329 (19)	0.054 (2)	−0.0020 (16)	0.0063 (16)	0.0046 (16)
C11	0.038 (2)	0.0348 (19)	0.058 (2)	0.0015 (16)	0.0054 (16)	0.0067 (17)
C12	0.044 (2)	0.045 (2)	0.054 (3)	0.0057 (17)	0.0066 (17)	0.0051 (17)
C13	0.0359 (19)	0.0331 (18)	0.065 (3)	0.0057 (14)	0.0081 (16)	0.0081 (17)
C14	0.043 (2)	0.047 (2)	0.059 (3)	0.0061 (17)	0.0087 (17)	0.0080 (18)
C15	0.050 (2)	0.060 (3)	0.064 (3)	0.006 (2)	0.0025 (19)	0.016 (2)
C16	0.057 (3)	0.066 (3)	0.053 (2)	−0.003 (2)	0.0024 (19)	0.013 (2)
C17	0.059 (3)	0.059 (3)	0.063 (3)	0.001 (2)	0.018 (2)	0.012 (2)
C18	0.049 (2)	0.051 (2)	0.064 (3)	0.0026 (18)	0.0158 (19)	0.0096 (19)
C19	0.042 (2)	0.0363 (19)	0.065 (2)	0.0021 (15)	0.0154 (17)	0.0079 (17)
C20	0.046 (2)	0.046 (2)	0.059 (2)	0.0073 (18)	0.0093 (18)	0.0084 (18)
C1'	0.038 (2)	0.039 (2)	0.060 (2)	−0.0012 (16)	0.0065 (17)	0.0073 (17)
C2'	0.045 (2)	0.0330 (19)	0.055 (2)	0.0021 (16)	0.0100 (17)	0.0065 (16)
C3'	0.045 (2)	0.053 (2)	0.061 (3)	−0.0004 (18)	0.0114 (18)	0.0114 (19)
C4'	0.059 (3)	0.072 (3)	0.054 (3)	0.007 (2)	0.013 (2)	0.013 (2)
C5'	0.063 (3)	0.072 (3)	0.049 (2)	0.013 (2)	0.003 (2)	0.003 (2)
C6'	0.049 (2)	0.058 (3)	0.062 (3)	0.0041 (19)	0.0021 (19)	0.0034 (19)
C7'	0.043 (2)	0.041 (2)	0.062 (3)	0.0055 (17)	0.0073 (17)	0.0083 (17)
C8'	0.042 (2)	0.051 (2)	0.067 (3)	−0.0062 (18)	0.0022 (19)	0.0087 (19)
C9'	0.043 (2)	0.045 (2)	0.058 (2)	0.0000 (17)	0.0106 (17)	0.0067 (18)
C10'	0.045 (2)	0.0319 (18)	0.050 (2)	0.0036 (16)	0.0103 (16)	0.0042 (16)
C11'	0.042 (2)	0.0345 (19)	0.054 (2)	0.0047 (16)	0.0098 (16)	0.0065 (16)
C12'	0.041 (2)	0.044 (2)	0.056 (2)	−0.0016 (17)	0.0085 (17)	0.0050 (17)
C13'	0.044 (2)	0.0386 (19)	0.055 (2)	0.0039 (16)	0.0121 (17)	0.0044 (16)
C14'	0.053 (2)	0.050 (2)	0.057 (3)	0.0013 (18)	0.0178 (19)	0.0058 (18)
C15'	0.056 (3)	0.063 (3)	0.055 (3)	0.005 (2)	0.017 (2)	0.0069 (19)
C16'	0.059 (3)	0.068 (3)	0.042 (2)	0.008 (2)	0.0062 (18)	0.0022 (19)
C17'	0.047 (2)	0.059 (3)	0.056 (3)	0.0019 (19)	0.0024 (18)	0.0024 (19)
C18'	0.040 (2)	0.041 (2)	0.064 (3)	−0.0002 (16)	0.0087 (17)	0.0077 (17)
C19'	0.0365 (19)	0.0377 (19)	0.057 (2)	0.0035 (15)	0.0105 (16)	0.0057 (16)
C20'	0.038 (2)	0.043 (2)	0.058 (2)	0.0019 (16)	0.0082 (17)	0.0098 (17)

Geometric parameters (Å, º) top

C1—C2	1.353 (5)	C1'—C10'	1.382 (5)
C1—C10	1.426 (5)	C1'—C2'	1.402 (5)
C1—H1	0.9300	C1'—H1'	0.9300
C2—C3	1.411 (6)	C2'—C7'	1.415 (5)
C2—H2	0.9300	C2'—C3'	1.423 (5)
C3—C8	1.423 (5)	C3'—C4'	1.361 (6)
C3—C4	1.431 (6)	C3'—H3'	0.9300
C4—C5	1.362 (7)	C4'—C5'	1.397 (6)
C4—H4	0.9300	C4'—H4'	0.9300
C5—C6	1.395 (7)	C5'—C6'	1.365 (6)
C5—H5	0.9300	C5'—H5'	0.9300
C6—C7	1.357 (5)	C6'—C7'	1.425 (5)
C6—H6	0.9300	C6'—H6'	0.9300
C7—C8	1.410 (5)	C7'—C8'	1.412 (5)
C7—H7	0.9300	C8'—C9'	1.348 (5)
C8—C9	1.400 (5)	C8'—H8'	0.9300
C9—C10	1.373 (5)	C9'—C10'	1.418 (5)
C9—H9	0.9300	C9'—H9'	0.9300
C10—C11	1.469 (5)	C10'—C11'	1.471 (5)
C11—C20	1.391 (5)	C11'—C12'	1.401 (5)
C11—C12	1.408 (5)	C11'—C20'	1.407 (5)
C12—C13	1.386 (5)	C12'—C13'	1.390 (5)
C12—H12	0.9300	C12'—H12'	0.9300
C13—C14	1.389 (5)	C13'—C14'	1.384 (5)
C13—C19	1.488 (5)	C13'—C19'	1.490 (5)
C14—C15	1.379 (5)	C14'—C15'	1.379 (5)
C14—H14	0.9300	C14'—H14'	0.9300
C15—C16	1.395 (6)	C15'—C16'	1.372 (6)
C15—H15	0.9300	C15'—H15'	0.9300
C16—C17	1.376 (6)	C16'—C17'	1.394 (6)
C16—H16	0.9300	C16'—H16'	0.9300
C17—C18	1.371 (6)	C17'—C18'	1.386 (5)
C17—H17	0.9300	C17'—H17'	0.9300
C18—C19	1.383 (5)	C18'—C19'	1.383 (5)
C18—H18	0.9300	C18'—H18'	0.9300
C19—C20	1.396 (5)	C19'—C20'	1.398 (5)
C20—H20	0.9300	C20'—H20'	0.9300

C2—C1—C10	122.0 (4)	C10'—C1'—C2'	121.3 (3)
C2—C1—H1	119.0	C10'—C1'—H1'	119.3
C10—C1—H1	119.0	C2'—C1'—H1'	119.3
C1—C2—C3	120.7 (4)	C1'—C2'—C7'	120.0 (3)
C1—C2—H2	119.7	C1'—C2'—C3'	122.1 (3)
C3—C2—H2	119.7	C7'—C2'—C3'	117.8 (4)
C2—C3—C8	118.4 (4)	C4'—C3'—C2'	121.4 (4)
C2—C3—C4	122.4 (4)	C4'—C3'—H3'	119.3
C8—C3—C4	119.2 (4)	C2'—C3'—H3'	119.3
C5—C4—C3	119.4 (4)	C3'—C4'—C5'	120.3 (4)
C5—C4—H4	120.3	C3'—C4'—H4'	119.8
C3—C4—H4	120.3	C5'—C4'—H4'	119.8
C4—C5—C6	121.5 (4)	C6'—C5'—C4'	120.6 (4)
C4—C5—H5	119.2	C6'—C5'—H5'	119.7
C6—C5—H5	119.2	C4'—C5'—H5'	119.7
C7—C6—C5	120.1 (4)	C5'—C6'—C7'	120.3 (4)
C7—C6—H6	120.0	C5'—C6'—H6'	119.9
C5—C6—H6	120.0	C7'—C6'—H6'	119.9
C6—C7—C8	121.6 (4)	C8'—C7'—C2'	118.0 (4)
C6—C7—H7	119.2	C8'—C7'—C6'	122.5 (4)
C8—C7—H7	119.2	C2'—C7'—C6'	119.4 (4)
C9—C8—C7	122.7 (3)	C9'—C8'—C7'	120.7 (4)
C9—C8—C3	119.2 (4)	C9'—C8'—H8'	119.7
C7—C8—C3	118.1 (4)	C7'—C8'—H8'	119.7
C10—C9—C8	122.3 (3)	C8'—C9'—C10'	122.5 (3)
C10—C9—H9	118.9	C8'—C9'—H9'	118.8
C8—C9—H9	118.9	C10'—C9'—H9'	118.8
C9—C10—C1	117.5 (3)	C1'—C10'—C9'	117.4 (3)
C9—C10—C11	122.9 (3)	C1'—C10'—C11'	122.2 (3)
C1—C10—C11	119.5 (3)	C9'—C10'—C11'	120.3 (3)
C20—C11—C12	107.7 (3)	C12'—C11'—C20'	108.1 (3)
C20—C11—C10	126.5 (3)	C12'—C11'—C10'	125.3 (3)
C12—C11—C10	125.7 (3)	C20'—C11'—C10'	126.5 (3)
C13—C12—C11	110.1 (3)	C13'—C12'—C11'	109.4 (3)
C13—C12—H12	124.9	C13'—C12'—H12'	125.3
C11—C12—H12	124.9	C11'—C12'—H12'	125.3
C12—C13—C14	126.5 (3)	C14'—C13'—C12'	125.9 (4)
C12—C13—C19	105.9 (3)	C14'—C13'—C19'	127.1 (4)
C14—C13—C19	127.6 (4)	C12'—C13'—C19'	107.0 (3)
C15—C14—C13	129.0 (4)	C15'—C14'—C13'	128.5 (4)
C15—C14—H14	115.5	C15'—C14'—H14'	115.7
C13—C14—H14	115.5	C13'—C14'—H14'	115.7
C14—C15—C16	128.1 (4)	C16'—C15'—C14'	129.5 (4)
C14—C15—H15	116.0	C16'—C15'—H15'	115.3
C16—C15—H15	116.0	C14'—C15'—H15'	115.3
C17—C16—C15	129.9 (4)	C15'—C16'—C17'	130.0 (4)
C17—C16—H16	115.1	C15'—C16'—H16'	115.0
C15—C16—H16	115.1	C17'—C16'—H16'	115.0
C18—C17—C16	129.6 (4)	C18'—C17'—C16'	128.7 (4)
C18—C17—H17	115.2	C18'—C17'—H17'	115.7
C16—C17—H17	115.2	C16'—C17'—H17'	115.7
C17—C18—C19	128.9 (4)	C19'—C18'—C17'	128.2 (4)
C17—C18—H18	115.6	C19'—C18'—H18'	115.9
C19—C18—H18	115.6	C17'—C18'—H18'	115.9
C18—C19—C20	126.8 (4)	C18'—C19'—C20'	126.2 (3)
C18—C19—C13	126.9 (4)	C18'—C19'—C13'	128.1 (3)
C20—C19—C13	106.3 (3)	C20'—C19'—C13'	105.6 (3)
C11—C20—C19	109.9 (3)	C19'—C20'—C11'	109.8 (3)
C11—C20—H20	125.0	C19'—C20'—H20'	125.1
C19—C20—H20	125.0	C11'—C20'—H20'	125.1

C10—C1—C2—C3	−0.3 (6)	C10'—C1'—C2'—C7'	−1.4 (5)
C1—C2—C3—C8	−1.2 (6)	C10'—C1'—C2'—C3'	176.2 (3)
C1—C2—C3—C4	178.3 (4)	C1'—C2'—C3'—C4'	−176.9 (4)
C2—C3—C4—C5	179.5 (4)	C7'—C2'—C3'—C4'	0.7 (5)
C8—C3—C4—C5	−1.0 (6)	C2'—C3'—C4'—C5'	1.1 (6)
C3—C4—C5—C6	0.2 (7)	C3'—C4'—C5'—C6'	−2.2 (7)
C4—C5—C6—C7	0.3 (8)	C4'—C5'—C6'—C7'	1.5 (7)
C5—C6—C7—C8	0.1 (7)	C1'—C2'—C7'—C8'	−1.4 (5)
C6—C7—C8—C9	178.9 (4)	C3'—C2'—C7'—C8'	−179.1 (3)
C6—C7—C8—C3	−0.9 (6)	C1'—C2'—C7'—C6'	176.3 (3)
C2—C3—C8—C9	1.1 (5)	C3'—C2'—C7'—C6'	−1.4 (5)
C4—C3—C8—C9	−178.4 (4)	C5'—C6'—C7'—C8'	177.9 (4)
C2—C3—C8—C7	−179.1 (4)	C5'—C6'—C7'—C2'	0.3 (6)
C4—C3—C8—C7	1.3 (5)	C2'—C7'—C8'—C9'	2.3 (5)
C7—C8—C9—C10	−179.2 (4)	C6'—C7'—C8'—C9'	−175.4 (3)
C3—C8—C9—C10	0.5 (5)	C7'—C8'—C9'—C10'	−0.3 (6)
C8—C9—C10—C1	−2.0 (5)	C2'—C1'—C10'—C9'	3.3 (5)
C8—C9—C10—C11	175.9 (3)	C2'—C1'—C10'—C11'	−174.8 (3)
C2—C1—C10—C9	1.9 (5)	C8'—C9'—C10'—C1'	−2.5 (5)
C2—C1—C10—C11	−176.0 (3)	C8'—C9'—C10'—C11'	175.7 (3)
C9—C10—C11—C20	−172.8 (4)	C1'—C10'—C11'—C12'	175.6 (4)
C1—C10—C11—C20	5.0 (5)	C9'—C10'—C11'—C12'	−2.4 (5)
C9—C10—C11—C12	3.7 (5)	C1'—C10'—C11'—C20'	−3.0 (5)
C1—C10—C11—C12	−178.5 (4)	C9'—C10'—C11'—C20'	178.9 (4)
C20—C11—C12—C13	−0.7 (4)	C20'—C11'—C12'—C13'	−1.3 (4)
C10—C11—C12—C13	−177.7 (3)	C10'—C11'—C12'—C13'	179.8 (3)
C11—C12—C13—C14	−179.4 (3)	C11'—C12'—C13'—C14'	−178.7 (4)
C11—C12—C13—C19	0.0 (4)	C11'—C12'—C13'—C19'	1.1 (4)
C12—C13—C14—C15	178.8 (4)	C12'—C13'—C14'—C15'	178.2 (4)
C19—C13—C14—C15	−0.5 (6)	C19'—C13'—C14'—C15'	−1.5 (7)
C13—C14—C15—C16	0.5 (7)	C13'—C14'—C15'—C16'	0.2 (8)
C14—C15—C16—C17	0.3 (8)	C14'—C15'—C16'—C17'	1.4 (8)
C15—C16—C17—C18	−0.3 (8)	C15'—C16'—C17'—C18'	−1.2 (8)
C16—C17—C18—C19	−0.8 (7)	C16'—C17'—C18'—C19'	0.1 (7)
C17—C18—C19—C20	−179.4 (4)	C17'—C18'—C19'—C20'	−177.9 (4)
C17—C18—C19—C13	1.3 (7)	C17'—C18'—C19'—C13'	0.0 (6)
C12—C13—C19—C18	180.0 (4)	C14'—C13'—C19'—C18'	1.1 (6)
C14—C13—C19—C18	−0.6 (6)	C12'—C13'—C19'—C18'	−178.7 (3)
C12—C13—C19—C20	0.6 (4)	C14'—C13'—C19'—C20'	179.3 (4)
C14—C13—C19—C20	−179.9 (3)	C12'—C13'—C19'—C20'	−0.4 (4)
C12—C11—C20—C19	1.1 (4)	C18'—C19'—C20'—C11'	177.9 (3)
C10—C11—C20—C19	178.1 (3)	C13'—C19'—C20'—C11'	−0.4 (4)
C18—C19—C20—C11	179.6 (4)	C12'—C11'—C20'—C19'	1.0 (4)
C13—C19—C20—C11	−1.1 (4)	C10'—C11'—C20'—C19'	179.9 (3)

Hydrogen-bond geometry (Å, º) top

Cg1, Cg4, Cg5, Cg6, Cg7 and Cg8 are the centroids of the C1–C3,C8–C10, C13–C19, C1'-C2',C7'–C10', C2'–C7', C11'–C13',C19',C20' and C13'–C19' rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cg5ⁱ	0.93	2.84	3.488 (4)	128
C7—H7···Cg6ⁱⁱ	0.93	2.81	3.544 (4)	137
C8′—H8′···Cg1ⁱⁱⁱ	0.93	2.82	3.456 (4)	126
C14—H14···Cg7ⁱⁱ	0.93	2.75	3.430 (4)	131
C14′—H14′···Cg4ⁱⁱⁱ	0.93	2.77	3.485 (4)	135
C18—H18···Cg8ⁱ	0.93	2.73	3.446 (4)	134
C18′—H18′···Cg4	0.93	2.79	3.463 (4)	130

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

Experimental details

Crystal data
Chemical formula	C₂₀H₁₄
M_r	254.31
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	6.0754 (8), 7.6324 (11), 14.5662 (19)
α, β, γ (°)	97.997 (7), 97.179 (6), 90.526 (7)
V (Å³)	663.38 (16)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.35 × 0.32 × 0.13

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 1997)
T_min, T_max	0.975, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	3762, 2573, 2039
R_int	0.021
(sin θ/λ)_max (Å⁻¹)	0.616

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.130, 1.04
No. of reflections	2573
No. of parameters	361
No. of restraints	3
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.16

Computer programs: SMART (Bruker 1997), SAINT (Bruker 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008.

Hydrogen-bond geometry (Å, º) top

Cg1, Cg4, Cg5, Cg6, Cg7 and Cg8 are the centroids of the C1–C3,C8–C10, C13–C19, C1'-C2',C7'–C10', C2'–C7', C11'–C13',C19',C20' and C13'–C19' rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cg5ⁱ	0.93	2.84	3.488 (4)	128
C7—H7···Cg6ⁱⁱ	0.93	2.81	3.544 (4)	137
C8'—H8'···Cg1ⁱⁱⁱ	0.93	2.82	3.456 (4)	126
C14—H14···Cg7ⁱⁱ	0.93	2.75	3.430 (4)	131
C14'—H14'···Cg4ⁱⁱⁱ	0.93	2.77	3.485 (4)	135
C18—H18···Cg8ⁱ	0.93	2.73	3.446 (4)	134
C18'—H18'···Cg4	0.93	2.79	3.463 (4)	130

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

Acknowledgements

The authors are grateful for financial support from the program for New Century Excellent Talents in Lanzhou University (NCET), the NSFC (20503011, 20621091), the MOE (SRFDP 20050730007, 106152), the Chunhui project and the `111′ project.

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