6a,6b,12a,12b-Tetra­hydro­cyclo­octa­[3,4]­cyclo­buta­[1,2][8]­annulene

The cis,syn,cis-tricyclic [2+2]-dimer of cyclo­octatetraene, C₁₆H₁₆, crystallizes in space group Pca2₁ with two mol­ecules in the asymmetric unit. An extensive network of weak C—H...π(C=C) interactions between the two independent mol­ecules, A and B, as well as A...A and B...B interactions, are observed in the supramolecular assembly. The C—H groups point more towards one C atom than to the centre of the C=C bond. Notable among the interactions are bifurcated (cyclo­butane)C—H...C=C contacts that span transannularly the eight-membered ring.

S1. Comment

In recent years, the weak hydrogen bond-like interactions between C—H donor groups and π acceptors have been invoked with increasing frequency to explain diverse chemical and biological phenomenon-like biomolecular conformations, stereoselective reactions, chiral recognition and self-assembly processes among others (Nishio et al., 1998; Desiraju & Steiner, 1999). In addition, the role of C—H···π interactions in crystal packing has also been recognized through several examples wherein the solid-state architecture is determined by a network of weak hydrogen bonds involving alkene, alkyne and aromatic π bonds as acceptors. However, most of the systems studied so far have been multifunctional in which there could be some influence of other intermolecular forces, besides the C—H···π interactions, in determining the three-dimensional molecular packing (Steiner, 1995, Steiner et al., 1995; Platts et al., 1996; Batsanov et al., 1996; Madhavi et al., 1997; Lutz et al., 1998; Harder, 1999; Takahashi et al., 2001). Thus, the crystal structures of pure hydrocarbons can be more illuminating in delineating the interplay of weak C—H···π interactions in crystal packing.

While many examples of C—H···π interactions with alkyne and aromatic π bonds are known (McMullan et al., 1992), involvement of alkene π bonds in such interactions has been rarely encountered. A recent report in this context is the observation of C—H···π interactions in the low-temperature crystal structures of the simple hydrocarbons 1,7-octadiene and 1,9-decadiene (Bond, 2002). This finding prompts us to report on the crystal structure of the title compound, (I), which is an esoteric tricyclic hydrocarbon synthethized by Schroder & Martin (1966). There are two molecules in the asymmetric unit (denoted hereafter as A and B; Fig. 1). The determination of the crystal structure in the related centrosymmetric space group, Pbcm, was not successful. Hence, the non-centrosymmetric space group was chosen. The two independent molecules are found to be related by a non-crystallographic center of symmetry. The distribution of the torsion angles within molecules A and B are essentially the same, the values about the corresponding bonds showing variations of not more than about 2.5° (Table 1). The r.m.s. fit of the atoms from the two molecules is 0.041 Å. The molecular symmetry of both molecules is close to twofold symmetry, deviating from the expected mm2 symmetry.

A careful study of the intermolecular distances and the relevant angles of approach revealed many C—H···π contacts of the types (cyclobutane)C—H···C═C and (cyclooctene)C═C—H···C═C between molecules A and B, as well as A···A and B···B interactions. The geometric parameters of the significant intermolecular C—H···π interactions that are within acceptable limits are given in Table 2. Significantly, the large number of C—H···C(π) interactions encountered in (I) exhibit favorable directional characteristics, although the C—H groups do not target the mid-point of the C═C double bond, but are displaced towards one of the C atoms of the C═C group (Desiraju & Steiner, 1999). It should be mentioned that there are four H···H short contacts (H7···C20, H9···C22, H17···C14 and H31···C12), with distances in the range 2.34–2.56 Å, which are marginally close to the sum of the H-atom van der Waals radii (r_H = 1.2 Å). Such a situation appears to be caused by the exigencies of packing considerations. Fig. 2(a) shows the infinite wave-like C—H···Csp² interactions between A molecules along the b axis. A similar pattern (Fig. 2 b) is also observed between B molecules B. In both cases, the less acidic cyclobutane ring H atom participates in the interactions. To our knowledge, the participation of cyclobutane C—H in C—H···π interactions does not seem to have been observed. However, C—H···O contacts involving a cyclobutane C—H group has been reported (Mehta et al., 1999; Mehta & Vidya, 2000). A further novel aspect is that the cyclobutane H atoms in molecules A and B are involved in bifurcated C—H···π interactions, which span a `transannular 1,6-hydrogen bridge' in one of the cyclooctatriene rings, and generate a structural motif reminiscent of anti-Bredt alkenes (Hopf, 2000). It is tempting to speculate that the formation of this novel hydrogen-bridged anti-Bredt motif may contribute towards the carbon-centered directional preference of the C—H···π contacts in molecules A and B.

The overall pattern in the organization of the two crystallographically independent molecules in the crystal, viewed along the a axis (a = 12.016 Å), is shown in Fig. 3. It is observed that rows of A and B molecules are arranged along the c axis of the unit cell, repeating in the sequence ···A···B···A···B··· along the b axis, with infinite strands of wave-like patterns along the b axis connecting molecules A and B. Molecules A and B along the b axis are connected through C—H···π interactions involving contacts of types (cyclobutane)C—H···C═C and (cyclooctene)C═ C—H···C═C (Table 2).

It may be pertinent to raise the question of whether the molecular assembly observed in (I) could be attributed to the network of weak C—H···π interactions, particularly in view of the on-going debate on their role. In this context, it is noteworthy that the intermolecular contact distances between C and H atoms are well above the sum of their van der Waals radii in the crystal structure of the perhydro derivative cis,syn,cis-tricyclo[8.6.0.0^2,9]hexadecane, (II) (Spek et al., 1985). This lends support for the reality of C—H···π interactions in the unsaturated hexaene (I). Although some non-dispersive contributions from C—H···π interactions would be present, specific directional C—H···π forces appear to play a role in the observed pattern in the crystal of (I). It is reasonable to surmise that the unique tricyclic structure of hydrocarbon (I), with two conformationally flexible eight-membered rings, facilitates the generation of the extensive C—H···π network observed here.

In conclusion, we observe that in the crystalline state of (I), a pure hydrocarbon, an efficient network of C—H···π(sp²) interactions operate besides the non-directional van der Waals interactions in concert to generate the observed supramolecular organization. The involvement of the less acidic cyclobutane H atoms in a bifurcated interaction, forming a transannular `hydrogen bridge' in the eight-membered ring is also a noteworthy feature in the compound.

S2. Experimental

The synthesis of the cis,syn,cis-tricyclic [2 + 2]-dimer of cyclooctatetraene has been described by Schroder & Martin (1966). Suitable crystals were grown from a solution of (I) in dichloromethane and hexane by slow evaporation.

S3. Refinement

Due to the absence of any significant anomalous scatterers in (I), attempts to confirm the absolute structure by refinement of the Flack (1983) parameter in the presence of 2044 sets of Friedel equivalents led to an inconclusive value of −2(10) (Flack & Bernardinelli, 2000). Therefore, the intensities of the Friedel pairs were merged before the final refinement and the absolute structure was assigned arbitrarily. The H atoms were placed in idealized positions (C—H = 0.93–0.98 Å) and were constrained to ride on their parent atoms, with U_iso(H) values set at 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 1990).

Figures

	Fig. 1. Views of molecule A (left) and molecule B (right) of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented by circles of arbitrary size.
	Fig. 2. (a) C—H···π interactions between A molecules and (b) C—H···π interactions between B molecules.
	Fig. 3. C—H···π interactions between A and B molecules, viewed along the a axis.

6a,6 b,12a,12b-tetrahydrocycloocta[3,4]cyclobuta[a]cyclooctene

Crystal data

C16H16	F(000) = 896
Mr = 208.29	Dx = 1.157 Mg m^−3
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 1342 reflections
a = 12.016 (3) Å	θ = 2.3–23.4°
b = 10.347 (2) Å	µ = 0.07 mm^−1
c = 19.233 (4) Å	T = 293 K
V = 2391.1 (9) Å^3	Prism, colourless
Z = 8	0.40 × 0.20 × 0.20 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2255 independent reflections
Radiation source: fine-focus sealed tube	1899 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
ϕ and ω scans	θmax = 25.3°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −14→14
Tmin = 0.920, Tmax = 0.987	k = −12→12
16681 measured reflections	l = −21→23

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: inferred from neighbouring sites
wR(F^2) = 0.115	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0639P)^2 + 0.3136P] where P = (Fo^2 + 2Fc^2)/3
2255 reflections	(Δ/σ)max = 0.001
289 parameters	Δρmax = 0.16 e Å^−3
1 restraint	Δρmin = −0.15 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	0.3093 (3)	0.9606 (4)	0.13310 (19)	0.0515 (8)
H1	0.2694	0.9533	0.0888	0.062*
C2	0.4084 (3)	0.8719 (3)	0.13714 (19)	0.0499 (8)
H2	0.4127	0.8170	0.1753	0.060*
C3	0.4905 (4)	0.8652 (3)	0.0909 (2)	0.0572 (10)
H3	0.5434	0.8008	0.0975	0.069*
C4	0.5053 (4)	0.9493 (4)	0.0307 (3)	0.0661 (11)
H4	0.5127	0.9090	−0.0122	0.079*
C5	0.5092 (4)	1.0764 (4)	0.0310 (3)	0.0643 (11)
H5	0.5141	1.1156	−0.0124	0.077*
C6	0.5071 (3)	1.1637 (3)	0.0903 (2)	0.0534 (9)
H6	0.5650	1.2232	0.0915	0.064*
C7	0.4356 (3)	1.1725 (3)	0.14329 (19)	0.0521 (8)
H7	0.4554	1.2309	0.1779	0.062*
C8	0.3296 (3)	1.1028 (3)	0.15497 (19)	0.0527 (8)
H8	0.2699	1.1550	0.1345	0.063*
C9	0.2934 (3)	1.0670 (3)	0.22986 (19)	0.0518 (7)
H9	0.2424	1.1309	0.2499	0.062*
C10	0.3879 (3)	1.0344 (3)	0.27826 (19)	0.0516 (8)
H10	0.4600	1.0403	0.2610	0.062*
C11	0.3749 (4)	0.9979 (3)	0.3440 (3)	0.0617 (15)
H11	0.4393	0.9866	0.3702	0.074*
C12	0.2694 (5)	0.9738 (4)	0.3791 (3)	0.0748 (14)
H12	0.2545	1.0206	0.4193	0.090*
C13	0.1931 (3)	0.8903 (4)	0.3579 (2)	0.0742 (11)
H13	0.1279	0.8880	0.3840	0.089*
C14	0.1977 (3)	0.8020 (3)	0.2996 (2)	0.0634 (9)
H14	0.1865	0.7154	0.3106	0.076*
C15	0.2157 (3)	0.8257 (3)	0.2327 (2)	0.0635 (9)
H15	0.2191	0.7532	0.2042	0.076*
C16	0.2309 (3)	0.9509 (3)	0.1969 (2)	0.0568 (8)
H16	0.1573	0.9815	0.1824	0.068*
C17	0.4583 (3)	0.4273 (3)	0.3580 (2)	0.0528 (8)
H17	0.5084	0.3625	0.3381	0.063*
C18	0.3639 (3)	0.4598 (3)	0.31063 (19)	0.0518 (8)
H18	0.2926	0.4540	0.3291	0.062*
C19	0.3720 (4)	0.4956 (3)	0.2453 (3)	0.0596 (14)
H19	0.3061	0.5066	0.2206	0.072*
C20	0.4758 (5)	0.5196 (4)	0.2083 (3)	0.0707 (13)
H20	0.4880	0.4727	0.1678	0.085*
C21	0.5556 (3)	0.6034 (4)	0.2276 (2)	0.0695 (10)
H21	0.6192	0.6048	0.2000	0.083*
C22	0.5544 (3)	0.6924 (3)	0.2864 (2)	0.0642 (9)
H22	0.5668	0.7786	0.2751	0.077*
C23	0.5385 (2)	0.6694 (3)	0.35326 (19)	0.0581 (8)
H23	0.5375	0.7422	0.3816	0.070*
C24	0.5219 (3)	0.5435 (4)	0.3902 (2)	0.0551 (8)
H24	0.5952	0.5124	0.4051	0.066*
C25	0.4430 (3)	0.5373 (4)	0.4537 (2)	0.0528 (8)
H25	0.4826	0.5463	0.4980	0.063*
C26	0.3448 (3)	0.6251 (3)	0.44838 (19)	0.0493 (8)
H26	0.3411	0.6782	0.4095	0.059*
C27	0.2625 (4)	0.6344 (3)	0.4939 (2)	0.0568 (10)
H27	0.2095	0.6981	0.4858	0.068*
C28	0.2474 (5)	0.5546 (4)	0.5551 (3)	0.0700 (13)
H28	0.2394	0.5975	0.5973	0.084*
C29	0.2438 (4)	0.4263 (4)	0.5571 (3)	0.0650 (11)
H29	0.2387	0.3899	0.6012	0.078*
C30	0.2468 (4)	0.3354 (3)	0.4996 (2)	0.0561 (10)
H30	0.1893	0.2752	0.4996	0.067*
C31	0.3175 (3)	0.3239 (3)	0.4474 (2)	0.0556 (9)
H31	0.2982	0.2624	0.4142	0.067*
C32	0.4227 (3)	0.3939 (3)	0.4335 (2)	0.0539 (8)
H32	0.4830	0.3430	0.4542	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0443 (17)	0.0599 (19)	0.050 (2)	−0.0052 (17)	−0.0152 (15)	0.004 (2)
C2	0.0597 (19)	0.0422 (16)	0.0479 (18)	−0.0014 (15)	−0.0084 (17)	0.0015 (15)
C3	0.064 (2)	0.0515 (19)	0.056 (2)	0.0044 (17)	−0.0040 (18)	−0.0040 (18)
C4	0.080 (3)	0.072 (3)	0.046 (3)	−0.001 (2)	0.005 (2)	−0.003 (2)
C5	0.075 (2)	0.075 (2)	0.044 (2)	0.005 (2)	0.003 (2)	0.012 (2)
C6	0.0537 (19)	0.0516 (19)	0.055 (2)	−0.0050 (15)	−0.0054 (16)	0.0157 (17)
C7	0.0611 (19)	0.0426 (17)	0.0525 (19)	0.0020 (14)	−0.0053 (17)	0.0081 (16)
C8	0.0453 (16)	0.0495 (17)	0.063 (2)	0.0124 (14)	−0.0054 (15)	0.0163 (16)
C9	0.0468 (16)	0.0457 (15)	0.063 (2)	0.0118 (13)	0.0093 (16)	0.0055 (15)
C10	0.0512 (18)	0.0465 (16)	0.057 (2)	−0.0034 (16)	0.0003 (15)	−0.0047 (18)
C11	0.077 (4)	0.058 (2)	0.050 (4)	−0.0053 (15)	−0.004 (3)	−0.0015 (14)
C12	0.105 (4)	0.063 (2)	0.057 (3)	0.004 (2)	0.022 (3)	0.009 (2)
C13	0.066 (2)	0.076 (2)	0.081 (3)	0.0111 (19)	0.028 (2)	0.029 (2)
C14	0.0475 (17)	0.0595 (19)	0.083 (3)	−0.0055 (15)	0.0037 (17)	0.0186 (19)
C15	0.0474 (17)	0.064 (2)	0.079 (3)	−0.0118 (15)	−0.0050 (16)	0.0043 (19)
C16	0.0383 (17)	0.061 (2)	0.071 (2)	−0.0029 (15)	−0.0074 (16)	0.014 (2)
C17	0.0457 (16)	0.0439 (16)	0.069 (2)	0.0098 (13)	0.0078 (16)	0.0044 (15)
C18	0.0501 (18)	0.0493 (17)	0.056 (2)	0.0006 (16)	0.0039 (15)	−0.0094 (19)
C19	0.065 (3)	0.058 (2)	0.056 (4)	−0.0022 (14)	0.000 (3)	−0.0054 (14)
C20	0.089 (3)	0.062 (2)	0.062 (3)	0.010 (2)	0.018 (2)	−0.001 (2)
C21	0.061 (2)	0.073 (2)	0.074 (2)	0.0124 (18)	0.0212 (19)	0.020 (2)
C22	0.0477 (17)	0.0621 (19)	0.083 (2)	−0.0082 (15)	0.0051 (17)	0.0177 (19)
C23	0.0462 (16)	0.0574 (19)	0.071 (2)	−0.0107 (14)	−0.0032 (15)	0.0065 (17)
C24	0.0339 (16)	0.065 (2)	0.067 (2)	0.0013 (15)	−0.0077 (15)	0.018 (2)
C25	0.0449 (18)	0.0608 (19)	0.053 (2)	−0.0036 (18)	−0.0104 (16)	0.011 (2)
C26	0.0564 (18)	0.0421 (16)	0.0493 (18)	−0.0084 (15)	−0.0106 (17)	0.0042 (16)
C27	0.065 (2)	0.0462 (17)	0.059 (2)	−0.0003 (17)	0.0034 (19)	−0.0057 (18)
C28	0.086 (3)	0.073 (3)	0.052 (3)	−0.010 (2)	0.008 (3)	−0.012 (2)
C29	0.078 (2)	0.069 (2)	0.048 (3)	−0.015 (2)	0.000 (2)	0.011 (2)
C30	0.0592 (19)	0.0501 (18)	0.059 (2)	−0.0112 (16)	0.0008 (18)	0.0118 (17)
C31	0.061 (2)	0.0383 (17)	0.067 (2)	−0.0032 (14)	−0.0021 (18)	0.0080 (18)
C32	0.0476 (17)	0.0472 (17)	0.067 (2)	0.0078 (14)	−0.0030 (16)	0.0130 (16)

Geometric parameters (Å, º)

C1—C2	1.505 (5)	C17—C18	1.492 (5)
C1—C16	1.550 (5)	C17—C32	1.553 (5)
C1—C8	1.550 (5)	C17—C24	1.553 (5)
C1—H1	0.9800	C17—H17	0.9800
C2—C3	1.330 (6)	C18—C19	1.314 (7)
C2—H2	0.9300	C18—H18	0.9300
C3—C4	1.458 (7)	C19—C20	1.458 (7)
C3—H3	0.9300	C19—H19	0.9300
C4—C5	1.316 (5)	C20—C21	1.344 (7)
C4—H4	0.9300	C20—H20	0.9300
C5—C6	1.455 (7)	C21—C22	1.459 (5)
C5—H5	0.9300	C21—H21	0.9300
C6—C7	1.335 (6)	C22—C23	1.322 (5)
C6—H6	0.9300	C22—H22	0.9300
C7—C8	1.481 (5)	C23—C24	1.497 (5)
C7—H7	0.9300	C23—H23	0.9300
C8—C9	1.549 (5)	C24—C25	1.547 (5)
C8—H8	0.9800	C24—H24	0.9800
C9—C10	1.506 (5)	C25—C26	1.493 (5)
C9—C16	1.552 (5)	C25—C32	1.553 (5)
C9—H9	0.9800	C25—H25	0.9800
C10—C11	1.330 (7)	C26—C27	1.324 (6)
C10—H10	0.9300	C26—H26	0.9300
C11—C12	1.458 (8)	C27—C28	1.450 (7)
C11—H11	0.9300	C27—H27	0.9300
C12—C13	1.325 (7)	C28—C29	1.328 (5)
C12—H12	0.9300	C28—H28	0.9300
C13—C14	1.449 (6)	C29—C30	1.452 (7)
C13—H13	0.9300	C29—H29	0.9300
C14—C15	1.327 (5)	C30—C31	1.321 (6)
C14—H14	0.9300	C30—H30	0.9300
C15—C16	1.479 (5)	C31—C32	1.481 (5)
C15—H15	0.9300	C31—H31	0.9300
C16—H16	0.9800	C32—H32	0.9800
C2—C1—C16	113.6 (3)	C18—C17—C32	114.3 (3)
C2—C1—C8	116.1 (3)	C18—C17—C24	116.3 (3)
C16—C1—C8	86.7 (3)	C32—C17—C24	86.3 (3)
C2—C1—H1	112.7	C18—C17—H17	112.5
C16—C1—H1	112.7	C32—C17—H17	112.5
C8—C1—H1	112.7	C24—C17—H17	112.5
C3—C2—C1	125.7 (4)	C19—C18—C17	126.3 (4)
C3—C2—H2	117.1	C19—C18—H18	116.9
C1—C2—H2	117.1	C17—C18—H18	116.9
C2—C3—C4	126.2 (4)	C18—C19—C20	125.3 (5)
C2—C3—H3	116.9	C18—C19—H19	117.4
C4—C3—H3	116.9	C20—C19—H19	117.4
C5—C4—C3	126.7 (4)	C21—C20—C19	125.9 (5)
C5—C4—H4	116.7	C21—C20—H20	117.1
C3—C4—H4	116.7	C19—C20—H20	117.1
C4—C5—C6	128.5 (4)	C20—C21—C22	127.9 (4)
C4—C5—H5	115.7	C20—C21—H21	116.0
C6—C5—H5	115.7	C22—C21—H21	116.0
C7—C6—C5	130.7 (4)	C23—C22—C21	129.9 (3)
C7—C6—H6	114.7	C23—C22—H22	115.0
C5—C6—H6	114.7	C21—C22—H22	115.0
C6—C7—C8	129.5 (4)	C22—C23—C24	129.6 (3)
C6—C7—H7	115.3	C22—C23—H23	115.2
C8—C7—H7	115.3	C24—C23—H23	115.2
C7—C8—C9	119.9 (3)	C23—C24—C25	119.5 (3)
C7—C8—C1	123.8 (3)	C23—C24—C17	123.3 (3)
C9—C8—C1	88.9 (2)	C25—C24—C17	88.9 (3)
C7—C8—H8	107.4	C23—C24—H24	107.8
C9—C8—H8	107.4	C25—C24—H24	107.8
C1—C8—H8	107.4	C17—C24—H24	107.8
C10—C9—C8	114.6 (3)	C26—C25—C24	113.9 (3)
C10—C9—C16	116.4 (3)	C26—C25—C32	116.1 (3)
C8—C9—C16	86.6 (3)	C24—C25—C32	86.5 (3)
C10—C9—H9	112.3	C26—C25—H25	112.6
C8—C9—H9	112.3	C24—C25—H25	112.6
C16—C9—H9	112.3	C32—C25—H25	112.6
C11—C10—C9	124.3 (4)	C27—C26—C25	126.1 (4)
C11—C10—H10	117.9	C27—C26—H26	116.9
C9—C10—H10	117.9	C25—C26—H26	116.9
C10—C11—C12	126.2 (5)	C26—C27—C28	126.1 (4)
C10—C11—H11	116.9	C26—C27—H27	117.0
C12—C11—H11	116.9	C28—C27—H27	117.0
C13—C12—C11	124.8 (5)	C29—C28—C27	126.6 (3)
C13—C12—H12	117.6	C29—C28—H28	116.7
C11—C12—H12	117.6	C27—C28—H28	116.7
C12—C13—C14	128.5 (4)	C28—C29—C30	128.7 (3)
C12—C13—H13	115.7	C28—C29—H29	115.7
C14—C13—H13	115.7	C30—C29—H29	115.7
C15—C14—C13	129.8 (3)	C31—C30—C29	130.8 (4)
C15—C14—H14	115.1	C31—C30—H30	114.6
C13—C14—H14	115.1	C29—C30—H30	114.6
C14—C15—C16	129.3 (4)	C30—C31—C32	129.9 (4)
C14—C15—H15	115.3	C30—C31—H31	115.0
C16—C15—H15	115.3	C32—C31—H31	115.0
C15—C16—C1	120.0 (3)	C31—C32—C25	123.8 (3)
C15—C16—C9	123.2 (3)	C31—C32—C17	120.8 (3)
C1—C16—C9	88.8 (2)	C25—C32—C17	88.7 (2)
C15—C16—H16	107.6	C31—C32—H32	107.2
C1—C16—H16	107.6	C25—C32—H32	107.2
C9—C16—H16	107.6	C17—C32—H32	107.2
C16—C1—C2—C3	−177.0 (4)	C32—C17—C18—C19	177.5 (3)
C8—C1—C2—C3	−78.7 (5)	C24—C17—C18—C19	79.2 (4)
C1—C2—C3—C4	5.5 (7)	C17—C18—C19—C20	−4.8 (6)
C2—C3—C4—C5	54.0 (7)	C18—C19—C20—C21	−56.3 (6)
C3—C4—C5—C6	4.2 (6)	C19—C20—C21—C22	−3.4 (8)
C4—C5—C6—C7	−52.9 (7)	C20—C21—C22—C23	55.2 (6)
C5—C6—C7—C8	−6.2 (7)	C21—C22—C23—C24	3.2 (6)
C6—C7—C8—C9	146.3 (4)	C22—C23—C24—C25	−145.1 (4)
C6—C7—C8—C1	35.2 (5)	C22—C23—C24—C17	−34.9 (5)
C2—C1—C8—C7	33.6 (5)	C18—C17—C24—C23	−33.0 (4)
C16—C1—C8—C7	148.4 (3)	C32—C17—C24—C23	−148.4 (3)
C2—C1—C8—C9	−92.3 (3)	C18—C17—C24—C25	92.2 (3)
C16—C1—C8—C9	22.4 (3)	C32—C17—C24—C25	−23.2 (3)
C7—C8—C9—C10	−34.0 (4)	C23—C24—C25—C26	34.5 (4)
C1—C8—C9—C10	95.1 (3)	C17—C24—C25—C26	−93.9 (3)
C7—C8—C9—C16	−151.5 (3)	C23—C24—C25—C32	151.5 (3)
C1—C8—C9—C16	−22.4 (2)	C17—C24—C25—C32	23.2 (3)
C8—C9—C10—C11	−178.1 (3)	C24—C25—C26—C27	176.9 (4)
C16—C9—C10—C11	−79.2 (4)	C32—C25—C26—C27	78.7 (5)
C9—C10—C11—C12	4.8 (6)	C25—C26—C27—C28	−4.9 (7)
C10—C11—C12—C13	56.7 (6)	C26—C27—C28—C29	−54.0 (7)
C11—C12—C13—C14	3.2 (8)	C27—C28—C29—C30	−4.3 (6)
C12—C13—C14—C15	−56.2 (6)	C28—C29—C30—C31	52.4 (7)
C13—C14—C15—C16	−3.3 (6)	C29—C30—C31—C32	5.7 (8)
C14—C15—C16—C1	146.8 (4)	C30—C31—C32—C25	−33.4 (6)
C14—C15—C16—C9	36.3 (5)	C30—C31—C32—C17	−145.0 (4)
C2—C1—C16—C15	−33.7 (4)	C26—C25—C32—C31	−35.2 (5)
C8—C1—C16—C15	−150.8 (3)	C24—C25—C32—C31	−150.2 (4)
C2—C1—C16—C9	94.7 (3)	C26—C25—C32—C17	91.8 (3)
C8—C1—C16—C9	−22.4 (3)	C24—C25—C32—C17	−23.2 (2)
C10—C9—C16—C15	32.3 (4)	C18—C17—C32—C31	35.2 (4)
C8—C9—C16—C15	148.2 (3)	C24—C17—C32—C31	152.5 (3)
C10—C9—C16—C1	−93.5 (3)	C18—C17—C32—C25	−94.2 (3)
C8—C9—C16—C1	22.4 (3)	C24—C17—C32—C25	23.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···C20^i	0.93	3.05	3.834 (6)	143
C9—H9···C22^ii	0.98	2.99	3.953 (4)	168
C16—H16···C6^ii	0.98	2.94	3.584 (5)	124
C16—H16···C3^ii	0.98	3.10	4.015 (5)	155
C17—H17···C14^iii	0.98	2.94	3.895 (4)	166
C24—H24···C30^iii	0.98	3.02	3.647 (6)	123
C24—H24···C27^iii	0.98	3.04	3.965 (5)	157
C31—H31···C12^iv	0.93	3.08	3.896 (6)	147

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