Two strained hexahelicenophanes

The crystal structures of the [6]­helicenes 4,13-(1,10-deca­methyl­ene­dioxy)­hexahelicene, C₃₆H₃₄O₂, (I), and 4,13-(1,8-octa­methyl­ene­dioxy)­hexahelicene, C₃₄H₃₀O₂, (II), show strong steric interactions between the terminal benzene rings and the poly­methyl­ene­dioxy chains. The shortest ring A and F distances amount to 2.941 (3) and 2.902 (3) Å, respectively. The increased steric energy of the ground state is responsible for a significantly lower racemization barrier of (I) and (II) in comparison to the unsubstituted [6]­helicene.

Computing details

For both compounds, data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CORINC (Dräger, 1971); program(s) used to solve structure: SIR92 (Altomare, 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).

(I) 4,13-(1',10'-Decandioxy)hexahelicen

Crystal data

C36H34O2	Dx = 1.254 Mg m^−3
Mr = 498.63	Melting point: 252 K
Orthorhombic, Pbca	Cu Kα radiation, λ = 1.54178 Å
a = 16.8803 (5) Å	Cell parameters from 25 reflections
b = 16.1855 (4) Å	θ = 65–74°
c = 19.3262 (6) Å	µ = 0.59 mm^−1
V = 5280.2 (3) Å^3	T = 298 K
Z = 8	Rectangular block, yellow
F(000) = 2128	0.56 × 0.53 × 0.35 mm

Data collection

CAD4 Enraf Nonius diffractometer	Rint = 0.000
Radiation source: rotating anode	θmax = 75.1°, θmin = 4.4°
Graphite monochromator	h = −21→0
ω/2θ scans	k = 0→20
5436 measured reflections	l = 0→24
5436 independent reflections	3 standard reflections every 60 min
4367 reflections with I > 2σ(I)	intensity decay: 5%

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)] = 0.057	H-atom parameters constrained
wR(F^2) = 0.156	Calculated w = 1/[σ^2(Fo^2) + ( 0.0843P)^2 + 1.8869P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
5436 reflections	Δρmax = 0.46 e Å^−3
368 parameters	Δρmin = −0.28 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2l^3/sin(2q)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00122 (13)

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 on F² for ALL reflections except for 0 with very negative F² or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating _refine_ls_R_factor_obs 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
O2	0.61174 (8)	0.07509 (10)	0.63720 (8)	0.0584 (4)
O1	0.26831 (9)	−0.09229 (10)	0.91560 (8)	0.0605 (4)
C1	0.41472 (11)	−0.14762 (11)	0.74908 (10)	0.0448 (4)
H1	0.4471	−0.1609	0.7117	0.050 (6)*
C2	0.44797 (12)	−0.12847 (12)	0.81174 (10)	0.0499 (5)
H2	0.5028	−0.1296	0.8163	0.051 (6)*
C3	0.40169 (13)	−0.10730 (13)	0.86910 (11)	0.0524 (5)
H3	0.4255	−0.0921	0.9106	0.064 (7)*
C4	0.32100 (12)	−0.10924 (12)	0.86344 (10)	0.0480 (4)
C4A	0.28409 (11)	−0.13375 (11)	0.80048 (10)	0.0456 (4)
C5	0.20080 (12)	−0.14914 (13)	0.79807 (12)	0.0554 (5)
H5	0.1692	−0.1373	0.8362	0.071 (7)*
C6	0.16819 (12)	−0.18089 (14)	0.74037 (13)	0.0587 (5)
H6	0.1153	−0.1969	0.7412	0.060 (6)*
C7	0.17640 (13)	−0.22916 (14)	0.61988 (12)	0.0603 (6)
H7	0.1233	−0.2442	0.6216	0.063 (7)*
C6A	0.21227 (12)	−0.19072 (12)	0.67817 (11)	0.0511 (5)
C8	0.21886 (14)	−0.24379 (13)	0.56234 (12)	0.0599 (6)
H8	0.1965	−0.2746	0.5267	0.078 (8)*
C8A	0.29698 (13)	−0.21316 (12)	0.55493 (10)	0.0517 (5)
C9	0.34053 (14)	−0.23073 (12)	0.49390 (11)	0.0572 (5)
H9	0.3168	−0.2609	0.4586	0.065 (7)*
C10	0.41557 (14)	−0.20445 (13)	0.48642 (11)	0.0566 (5)
H10	0.4460	−0.2238	0.4497	0.075 (8)*
C10A	0.44884 (12)	−0.14727 (12)	0.53414 (10)	0.0488 (4)
C11	0.52705 (13)	−0.11639 (13)	0.52435 (11)	0.0543 (5)
H11	0.5582	−0.1382	0.4891	0.068 (7)*
C12	0.55693 (12)	−0.05632 (13)	0.56491 (10)	0.0511 (5)
H12	0.6101	−0.0418	0.5614	0.061 (7)*
C12A	0.50679 (11)	−0.01493 (11)	0.61337 (9)	0.0437 (4)
C13	0.53325 (11)	0.05783 (12)	0.64753 (10)	0.0462 (4)
C14	0.48137 (12)	0.10517 (13)	0.68463 (11)	0.0513 (5)
H14	0.4984	0.1536	0.7059	0.059 (6)*
C15	0.40224 (12)	0.08008 (12)	0.69036 (11)	0.0506 (5)
H15	0.3667	0.1134	0.7143	0.057 (6)*
C16	0.37601 (11)	0.00810 (11)	0.66185 (10)	0.0448 (4)
H16	0.3235	−0.0077	0.6677	0.050 (6)*
C16A	0.42808 (11)	−0.04274 (11)	0.62348 (9)	0.0418 (4)
C16B	0.40315 (11)	−0.11935 (11)	0.59060 (9)	0.0436 (4)
C16C	0.33141 (11)	−0.16434 (11)	0.60841 (10)	0.0448 (4)
C16D	0.29227 (11)	−0.16501 (11)	0.67521 (10)	0.0444 (4)
C16E	0.33151 (11)	−0.14724 (11)	0.74090 (10)	0.0427 (4)
C17	0.29292 (15)	−0.05357 (14)	0.97916 (11)	0.0607 (6)
H17A	0.3481	−0.0667	0.9878	0.069 (5)*
H17B	0.2619	−0.0757	1.0171	0.069 (5)*
C18	0.28301 (15)	0.03873 (15)	0.97689 (14)	0.0688 (6)
H18A	0.2864	0.0596	1.0238	0.093 (7)*
H18B	0.2301	0.0508	0.9600	0.093 (7)*
C19	0.34227 (14)	0.08622 (15)	0.93245 (14)	0.0678 (6)
H19A	0.3495	0.0576	0.8888	0.071 (5)*
H19B	0.3213	0.1407	0.9225	0.071 (5)*
C20	0.42203 (16)	0.09480 (19)	0.96851 (15)	0.0782 (7)
H20A	0.4146	0.1271	1.0103	0.108 (8)*
H20B	0.4397	0.0402	0.9824	0.108 (8)*
C21	0.48731 (18)	0.13487 (19)	0.92578 (17)	0.0869 (9)
H21A	0.4647	0.1808	0.9003	0.117 (9)*
H21B	0.5268	0.1572	0.9571	0.117 (9)*
C22	0.52777 (17)	0.07877 (17)	0.87573 (13)	0.0715 (7)
H22A	0.4893	0.0600	0.8419	0.099 (7)*
H22B	0.5467	0.0306	0.9005	0.099 (7)*
C23	0.59770 (16)	0.11826 (16)	0.83735 (13)	0.0689 (6)
H23A	0.5783	0.1633	0.8089	0.084 (6)*
H23B	0.6344	0.1412	0.8709	0.084 (6)*
C24	0.64128 (14)	0.05703 (15)	0.79187 (13)	0.0634 (6)
H24A	0.6027	0.0226	0.7684	0.074 (5)*
H24B	0.6731	0.0214	0.8211	0.074 (5)*
C25	0.69474 (13)	0.09652 (16)	0.73789 (13)	0.0651 (6)
H25A	0.7270	0.1382	0.7604	0.071 (5)*
H25B	0.7302	0.0546	0.7199	0.071 (5)*
C26	0.65194 (13)	0.13602 (14)	0.67803 (12)	0.0577 (5)
H26A	0.6138	0.1757	0.6955	0.067 (5)*
H26B	0.6897	0.1654	0.6493	0.067 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O2	0.0459 (8)	0.0685 (9)	0.0607 (9)	−0.0089 (7)	0.0037 (6)	−0.0099 (7)
O1	0.0599 (9)	0.0681 (9)	0.0534 (8)	0.0039 (7)	0.0082 (7)	−0.0072 (7)
C1	0.0474 (10)	0.0426 (9)	0.0444 (9)	0.0028 (8)	−0.0014 (8)	0.0040 (8)
C2	0.0449 (10)	0.0524 (11)	0.0523 (11)	0.0026 (8)	−0.0054 (8)	0.0020 (9)
C3	0.0570 (12)	0.0545 (11)	0.0456 (10)	0.0025 (9)	−0.0065 (9)	−0.0008 (9)
C4	0.0552 (11)	0.0416 (9)	0.0471 (10)	0.0039 (8)	0.0039 (8)	0.0028 (8)
C4A	0.0484 (10)	0.0376 (9)	0.0507 (10)	0.0026 (7)	−0.0002 (8)	0.0057 (8)
C5	0.0493 (11)	0.0552 (12)	0.0617 (12)	0.0027 (9)	0.0051 (9)	0.0068 (10)
C6	0.0410 (10)	0.0598 (12)	0.0752 (14)	−0.0046 (9)	−0.0032 (10)	0.0084 (11)
C7	0.0543 (12)	0.0533 (12)	0.0735 (15)	−0.0104 (9)	−0.0190 (11)	0.0082 (10)
C6A	0.0488 (11)	0.0448 (10)	0.0598 (12)	−0.0023 (8)	−0.0096 (9)	0.0087 (9)
C8	0.0691 (13)	0.0468 (11)	0.0638 (13)	−0.0070 (10)	−0.0230 (11)	0.0020 (10)
C8A	0.0666 (13)	0.0384 (9)	0.0502 (11)	0.0016 (8)	−0.0161 (9)	0.0035 (8)
C9	0.0802 (15)	0.0433 (10)	0.0483 (11)	0.0015 (10)	−0.0161 (10)	−0.0032 (9)
C10	0.0774 (15)	0.0475 (11)	0.0449 (10)	0.0103 (10)	−0.0047 (10)	−0.0050 (9)
C10A	0.0598 (12)	0.0428 (9)	0.0439 (10)	0.0091 (8)	−0.0042 (8)	0.0016 (8)
C11	0.0590 (12)	0.0570 (12)	0.0469 (10)	0.0141 (10)	0.0051 (9)	−0.0016 (9)
C12	0.0464 (11)	0.0568 (11)	0.0501 (10)	0.0066 (9)	0.0029 (8)	0.0026 (9)
C12A	0.0447 (9)	0.0458 (10)	0.0406 (9)	0.0046 (8)	−0.0025 (7)	0.0053 (7)
C13	0.0421 (9)	0.0502 (10)	0.0463 (10)	−0.0008 (8)	−0.0018 (8)	0.0049 (8)
C14	0.0500 (11)	0.0469 (10)	0.0568 (11)	−0.0031 (8)	−0.0026 (9)	−0.0057 (9)
C15	0.0492 (10)	0.0438 (10)	0.0587 (12)	0.0061 (8)	0.0036 (9)	−0.0030 (9)
C16	0.0412 (9)	0.0403 (9)	0.0528 (10)	0.0016 (7)	0.0007 (8)	0.0030 (8)
C16A	0.0462 (10)	0.0397 (9)	0.0394 (9)	0.0040 (7)	−0.0041 (7)	0.0049 (7)
C16B	0.0492 (10)	0.0403 (9)	0.0414 (9)	0.0055 (7)	−0.0062 (8)	0.0029 (7)
C16C	0.0506 (10)	0.0369 (9)	0.0469 (10)	0.0025 (7)	−0.0095 (8)	0.0036 (7)
C16D	0.0476 (10)	0.0358 (9)	0.0498 (10)	0.0015 (7)	−0.0077 (8)	0.0041 (7)
C16E	0.0478 (10)	0.0346 (8)	0.0458 (9)	0.0008 (7)	−0.0034 (8)	0.0052 (7)
C17	0.0729 (15)	0.0604 (13)	0.0487 (11)	0.0038 (11)	0.0071 (10)	−0.0055 (10)
C18	0.0652 (14)	0.0600 (13)	0.0813 (16)	0.0071 (11)	0.0079 (12)	−0.0128 (12)
C19	0.0686 (15)	0.0554 (13)	0.0793 (16)	0.0097 (11)	−0.0048 (12)	−0.0038 (11)
C20	0.0697 (16)	0.0839 (18)	0.0810 (17)	0.0029 (13)	−0.0042 (13)	−0.0128 (15)
C21	0.0817 (18)	0.0793 (18)	0.100 (2)	−0.0131 (15)	0.0008 (17)	−0.0224 (16)
C22	0.0832 (17)	0.0694 (15)	0.0618 (14)	−0.0097 (13)	−0.0009 (13)	−0.0037 (12)
C23	0.0754 (16)	0.0705 (15)	0.0606 (14)	−0.0079 (12)	−0.0069 (12)	−0.0032 (12)
C24	0.0594 (13)	0.0644 (13)	0.0665 (14)	0.0016 (10)	−0.0110 (11)	0.0044 (11)
C25	0.0470 (11)	0.0760 (15)	0.0722 (15)	−0.0024 (10)	−0.0063 (10)	−0.0042 (12)
C26	0.0488 (11)	0.0590 (12)	0.0652 (13)	−0.0128 (9)	0.0023 (10)	0.0001 (10)

Geometric parameters (Å, º)

O2—C13	1.369 (2)	C10A—C11	1.424 (3)
O2—C26	1.434 (3)	C11—C12	1.347 (3)
O1—C4	1.372 (2)	C12—C12A	1.429 (3)
O1—C17	1.440 (3)	C12A—C16A	1.416 (3)
C1—C2	1.370 (3)	C12A—C13	1.422 (3)
C1—C16E	1.414 (3)	C13—C14	1.367 (3)
C2—C3	1.399 (3)	C14—C15	1.400 (3)
C3—C4	1.367 (3)	C15—C16	1.363 (3)
C4—C4A	1.424 (3)	C16—C16A	1.414 (3)
C4A—C16E	1.419 (3)	C16A—C16B	1.455 (3)
C4A—C5	1.429 (3)	C16B—C16C	1.454 (3)
C5—C6	1.346 (3)	C16C—C16D	1.450 (3)
C6—C6A	1.423 (3)	C16D—C16E	1.460 (3)
C7—C8	1.344 (3)	C17—C18	1.504 (3)
C7—C6A	1.422 (3)	C18—C19	1.526 (4)
C6A—C16D	1.414 (3)	C19—C20	1.522 (4)
C8—C8A	1.416 (3)	C20—C21	1.522 (4)
C8A—C9	1.419 (3)	C21—C22	1.492 (4)
C8A—C16C	1.425 (3)	C22—C23	1.534 (4)
C9—C10	1.344 (3)	C23—C24	1.515 (3)
C10—C10A	1.422 (3)	C24—C25	1.520 (3)
C10A—C16B	1.410 (3)	C25—C26	1.506 (3)
C13—O2—C26	121.21 (16)	C14—C13—O2	125.62 (18)
C4—O1—C17	121.78 (17)	C14—C13—C12A	120.42 (18)
C2—C1—C16E	120.32 (18)	O2—C13—C12A	113.92 (17)
C1—C2—C3	121.80 (19)	C13—C14—C15	119.35 (18)
C4—C3—C2	119.18 (19)	C16—C15—C14	121.72 (19)
C3—C4—O1	125.63 (19)	C15—C16—C16A	120.50 (18)
C3—C4—C4A	120.73 (18)	C16—C16A—C12A	118.06 (17)
O1—C4—C4A	113.58 (17)	C16—C16A—C16B	123.02 (17)
C16E—C4A—C4	119.31 (17)	C12A—C16A—C16B	118.80 (16)
C16E—C4A—C5	120.12 (19)	C10A—C16B—C16C	118.56 (17)
C4—C4A—C5	120.48 (18)	C10A—C16B—C16A	116.91 (17)
C6—C5—C4A	119.7 (2)	C16C—C16B—C16A	124.33 (17)
C5—C6—C6A	121.93 (19)	C8A—C16C—C16D	117.11 (17)
C8—C7—C6A	120.4 (2)	C8A—C16C—C16B	116.46 (18)
C16D—C6A—C7	120.2 (2)	C16D—C16C—C16B	126.42 (17)
C16D—C6A—C6	120.04 (19)	C6A—C16D—C16C	118.24 (17)
C7—C6A—C6	119.70 (19)	C6A—C16D—C16E	117.12 (18)
C7—C8—C8A	121.2 (2)	C16C—C16D—C16E	124.45 (17)
C8—C8A—C9	119.77 (19)	C1—C16E—C4A	118.06 (17)
C8—C8A—C16C	120.0 (2)	C1—C16E—C16D	123.16 (17)
C9—C8A—C16C	120.2 (2)	C4A—C16E—C16D	118.67 (17)
C10—C9—C8A	120.95 (19)	O1—C17—C18	112.0 (2)
C9—C10—C10A	120.6 (2)	C17—C18—C19	116.3 (2)
C16B—C10A—C10	119.6 (2)	C20—C19—C18	111.6 (2)
C16B—C10A—C11	119.82 (18)	C21—C20—C19	115.5 (3)
C10—C10A—C11	120.54 (19)	C22—C21—C20	115.1 (2)
C12—C11—C10A	121.54 (19)	C21—C22—C23	114.3 (2)
C11—C12—C12A	119.87 (19)	C24—C23—C22	112.4 (2)
C16A—C12A—C13	119.60 (17)	C23—C24—C25	114.3 (2)
C16A—C12A—C12	119.79 (18)	C26—C25—C24	114.88 (19)
C13—C12A—C12	120.43 (18)	O2—C26—C25	110.96 (19)
C16E—C1—C2—C3	−0.6 (3)	C10—C10A—C16B—C16C	15.1 (3)
C1—C2—C3—C4	2.9 (3)	C11—C10A—C16B—C16C	−166.58 (17)
C2—C3—C4—O1	178.16 (18)	C10—C10A—C16B—C16A	−159.91 (17)
C2—C3—C4—C4A	1.0 (3)	C11—C10A—C16B—C16A	18.4 (3)
C17—O1—C4—C3	13.2 (3)	C16—C16A—C16B—C10A	156.43 (17)
C17—O1—C4—C4A	−169.46 (17)	C12A—C16A—C16B—C10A	−19.7 (2)
C3—C4—C4A—C16E	−7.1 (3)	C16—C16A—C16B—C16C	−18.2 (3)
O1—C4—C4A—C16E	175.42 (16)	C12A—C16A—C16B—C16C	165.68 (16)
C3—C4—C4A—C5	169.40 (19)	C8—C8A—C16C—C16D	14.8 (3)
O1—C4—C4A—C5	−8.0 (3)	C9—C8A—C16C—C16D	−165.69 (17)
C16E—C4A—C5—C6	3.8 (3)	C8—C8A—C16C—C16B	−165.88 (17)
C4—C4A—C5—C6	−172.74 (19)	C9—C8A—C16C—C16B	13.6 (3)
C4A—C5—C6—C6A	−7.7 (3)	C10A—C16B—C16C—C8A	−22.1 (2)
C8—C7—C6A—C16D	2.2 (3)	C16A—C16B—C16C—C8A	152.50 (17)
C8—C7—C6A—C6	−175.6 (2)	C10A—C16B—C16C—C16D	157.18 (17)
C5—C6—C6A—C16D	−1.5 (3)	C16A—C16B—C16C—C16D	−28.2 (3)
C5—C6—C6A—C7	176.2 (2)	C7—C6A—C16D—C16C	11.5 (3)
C6A—C7—C8—C8A	−7.4 (3)	C6—C6A—C16D—C16C	−170.74 (17)
C7—C8—C8A—C9	179.13 (19)	C7—C6A—C16D—C16E	−163.72 (18)
C7—C8—C8A—C16C	−1.3 (3)	C6—C6A—C16D—C16E	14.0 (3)
C8—C8A—C9—C10	−178.04 (19)	C8A—C16C—C16D—C6A	−19.6 (3)
C16C—C8A—C9—C10	2.4 (3)	C16B—C16C—C16D—C6A	161.19 (17)
C8A—C9—C10—C10A	−10.3 (3)	C8A—C16C—C16D—C16E	155.30 (17)
C9—C10—C10A—C16B	1.4 (3)	C16B—C16C—C16D—C16E	−24.0 (3)
C9—C10—C10A—C11	−176.97 (19)	C2—C1—C16E—C4A	−5.4 (3)
C16B—C10A—C11—C12	−4.9 (3)	C2—C1—C16E—C16D	178.42 (17)
C10—C10A—C11—C12	173.45 (19)	C4—C4A—C16E—C1	9.2 (3)
C10A—C11—C12—C12A	−7.9 (3)	C5—C4A—C16E—C1	−167.36 (18)
C11—C12—C12A—C16A	6.3 (3)	C4—C4A—C16E—C16D	−174.51 (16)
C11—C12—C12A—C13	−168.75 (18)	C5—C4A—C16E—C16D	8.9 (3)
C26—O2—C13—C14	14.6 (3)	C6A—C16D—C16E—C1	158.60 (18)
C26—O2—C13—C12A	−167.64 (18)	C16C—C16D—C16E—C1	−16.3 (3)
C16A—C12A—C13—C14	−6.2 (3)	C6A—C16D—C16E—C4A	−17.5 (2)
C12—C12A—C13—C14	168.89 (19)	C16C—C16D—C16E—C4A	167.58 (17)
C16A—C12A—C13—O2	175.89 (16)	C4—O1—C17—C18	93.8 (2)
C12—C12A—C13—O2	−9.0 (3)	O1—C17—C18—C19	−73.3 (3)
O2—C13—C14—C15	179.46 (19)	C17—C18—C19—C20	−77.2 (3)
C12A—C13—C14—C15	1.8 (3)	C18—C19—C20—C21	175.0 (2)
C13—C14—C15—C16	2.3 (3)	C19—C20—C21—C22	−80.9 (3)
C14—C15—C16—C16A	−1.9 (3)	C20—C21—C22—C23	−175.3 (2)
C15—C16—C16A—C12A	−2.5 (3)	C21—C22—C23—C24	175.0 (2)
C15—C16—C16A—C16B	−178.66 (17)	C22—C23—C24—C25	163.3 (2)
C13—C12A—C16A—C16	6.5 (3)	C23—C24—C25—C26	−73.3 (3)
C12—C12A—C16A—C16	−168.66 (17)	C13—O2—C26—C25	95.8 (2)
C13—C12A—C16A—C16B	−177.24 (16)	C24—C25—C26—O2	−66.1 (3)
C12—C12A—C16A—C16B	7.6 (2)

(II) 4,13-(1,8 octandioxy)-hexahelicen

Crystal data

C34H30O2	Dx = 1.286 Mg m^−3
Mr = 470.58	Melting point: 243 K
Orthorhombic, Pna21	Cu Kα radiation, λ = 1.54178 Å
a = 18.1447 (4) Å	Cell parameters from 25 reflections
b = 12.3799 (3) Å	θ = 66–74°
c = 10.8228 (3) Å	µ = 0.61 mm^−1
V = 2431.12 (10) Å^3	T = 298 K
Z = 4	Rectangular block, yellow
F(000) = 1000	0.41 × 0.41 × 0.32 mm

Data collection

CAD4 Enraf Nonius diffractometer	Rint = 0.000
Radiation source: rotating anode	θmax = 75.0°, θmin = 4.3°
Graphite monochromator	h = −22→22
ω/2θ scans	k = −15→15
4962 measured reflections	l = −13→13
4962 independent reflections	3 standard reflections every 60 min
4855 reflections with I > 2σ(I)	intensity decay: 5%

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.039	Calculated w = 1/[σ^2(Fo^2) + ( 0.0742P)^2 + 0.2614P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.111	(Δ/σ)max = 0.001
S = 1.07	Δρmax = 0.34 e Å^−3
4962 reflections	Δρmin = −0.18 e Å^−3
348 parameters	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2l^3/sin(2q)]^-1/4
1 restraint	Extinction coefficient: 0.0050 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Secondary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.05 (27)

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 on F² for ALL reflections except for 0 with very negative F² or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating _refine_ls_R_factor_obs 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
O1	0.93523 (7)	−0.06201 (10)	0.21811 (15)	0.0575 (4)
O2	0.65710 (7)	0.44666 (10)	0.29553 (15)	0.0579 (3)
C1	0.75394 (9)	0.04490 (13)	0.41749 (15)	0.0397 (3)
H1	0.7128	0.0717	0.4587	0.041 (5)*
C2	0.82178 (9)	0.08815 (14)	0.44095 (16)	0.0437 (3)
H2	0.8264	0.1416	0.5008	0.042 (5)*
C3	0.88432 (9)	0.05371 (14)	0.37685 (17)	0.0465 (4)
H3	0.9299	0.0854	0.3923	0.051 (5)*
C4	0.87797 (9)	−0.02715 (12)	0.29106 (17)	0.0435 (3)
C4A	0.80975 (9)	−0.08165 (12)	0.27443 (15)	0.0411 (3)
C5	0.80609 (11)	−0.18125 (14)	0.20703 (17)	0.0501 (4)
H5	0.8474	−0.2063	0.1649	0.043 (5)*
C6	0.74299 (12)	−0.23865 (13)	0.20462 (19)	0.0546 (4)
H6	0.7431	−0.3072	0.1694	0.069 (7)*
C6A	0.67602 (10)	−0.19685 (14)	0.25484 (16)	0.0480 (4)
C7	0.61018 (12)	−0.25995 (16)	0.25756 (19)	0.0582 (5)
H7	0.6095	−0.3273	0.2195	0.081 (8)*
C8	0.54900 (12)	−0.22331 (17)	0.31458 (19)	0.0599 (5)
H8	0.5087	−0.2690	0.3236	0.072 (7)*
C8A	0.54502 (10)	−0.11591 (15)	0.36120 (18)	0.0518 (4)
C9	0.48470 (10)	−0.07768 (19)	0.4338 (2)	0.0622 (5)
H9	0.4443	−0.1224	0.4474	0.081 (8)*
C10	0.48544 (10)	0.02253 (19)	0.4831 (2)	0.0602 (5)
H10	0.4512	0.0409	0.5434	0.071 (7)*
C10A	0.53821 (9)	0.10030 (16)	0.44330 (16)	0.0493 (4)
C11	0.53627 (10)	0.20997 (17)	0.48409 (17)	0.0538 (4)
H11	0.5044	0.2296	0.5476	0.060 (6)*
C12	0.58021 (9)	0.28623 (16)	0.43163 (18)	0.0504 (4)
H12	0.5824	0.3552	0.4655	0.060 (6)*
C12A	0.62313 (8)	0.26065 (13)	0.32438 (16)	0.0414 (3)
C13	0.65593 (9)	0.34202 (13)	0.25103 (17)	0.0456 (4)
C14	0.68265 (10)	0.31985 (15)	0.13612 (18)	0.0497 (4)
H14	0.6992	0.3754	0.0854	0.051 (5)*
C15	0.68502 (9)	0.21235 (14)	0.09500 (16)	0.0452 (4)
H15	0.7033	0.1970	0.0167	0.060 (6)*
C16	0.66066 (8)	0.12967 (13)	0.16893 (15)	0.0402 (3)
H16	0.6657	0.0585	0.1427	0.039 (5)*
C16A	0.62805 (8)	0.15183 (12)	0.28441 (14)	0.0376 (3)
C16B	0.59276 (8)	0.06875 (13)	0.35795 (15)	0.0419 (3)
C16C	0.60533 (9)	−0.04521 (14)	0.34002 (15)	0.0428 (3)
C16D	0.67517 (9)	−0.09163 (13)	0.30543 (15)	0.0411 (3)
C16E	0.74542 (8)	−0.04008 (12)	0.33142 (14)	0.0378 (3)
C17	0.98596 (9)	0.01887 (15)	0.1737 (2)	0.0535 (4)
H171	1.0297	−0.0167	0.1420	0.067 (5)*
H172	1.0009	0.0642	0.2424	0.067 (5)*
C18	0.95384 (13)	0.08957 (17)	0.07326 (19)	0.0592 (5)
H181	0.9278	0.0430	0.0160	0.092 (7)*
H182	0.9946	0.1216	0.0283	0.092 (7)*
C19	0.90134 (11)	0.18107 (15)	0.11024 (18)	0.0517 (4)
H191	0.8795	0.2114	0.0362	0.053 (4)*
H192	0.8618	0.1514	0.1602	0.053 (4)*
C20	0.93925 (10)	0.27097 (15)	0.1823 (2)	0.0532 (4)
H201	0.9529	0.2432	0.2629	0.070 (5)*
H202	0.9844	0.2902	0.1396	0.070 (5)*
C21	0.89364 (12)	0.37301 (15)	0.2005 (2)	0.0589 (5)
H211	0.9267	0.4317	0.2218	0.062 (5)*
H212	0.8705	0.3913	0.1224	0.062 (5)*
C22	0.83492 (11)	0.36593 (15)	0.2975 (2)	0.0591 (5)
H221	0.8572	0.3507	0.3770	0.058 (4)*
H222	0.8013	0.3075	0.2778	0.058 (4)*
C23	0.79186 (12)	0.47374 (16)	0.3043 (3)	0.0729 (7)
H231	0.8232	0.5267	0.3441	0.130 (10)*
H232	0.7834	0.4985	0.2204	0.130 (10)*
C24	0.72014 (12)	0.47311 (17)	0.3695 (3)	0.0708 (6)
H241	0.7231	0.4217	0.4370	0.079 (6)*
H242	0.7124	0.5440	0.4054	0.079 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0492 (7)	0.0460 (6)	0.0774 (9)	0.0061 (5)	0.0175 (7)	−0.0034 (6)
O2	0.0490 (6)	0.0421 (6)	0.0827 (10)	0.0028 (5)	−0.0052 (7)	−0.0106 (6)
C1	0.0415 (8)	0.0413 (7)	0.0363 (7)	0.0021 (6)	−0.0017 (6)	−0.0010 (6)
C2	0.0482 (8)	0.0433 (8)	0.0398 (8)	−0.0018 (6)	−0.0047 (7)	−0.0055 (6)
C3	0.0400 (8)	0.0473 (8)	0.0523 (9)	−0.0050 (6)	−0.0038 (7)	0.0001 (7)
C4	0.0417 (8)	0.0397 (7)	0.0491 (8)	0.0059 (6)	0.0028 (7)	0.0022 (7)
C4A	0.0473 (8)	0.0362 (7)	0.0399 (8)	0.0022 (6)	−0.0016 (7)	0.0018 (6)
C5	0.0596 (10)	0.0400 (8)	0.0506 (9)	0.0041 (7)	0.0028 (8)	−0.0062 (7)
C6	0.0745 (12)	0.0355 (7)	0.0539 (10)	−0.0010 (7)	−0.0056 (9)	−0.0082 (7)
C6A	0.0590 (10)	0.0409 (8)	0.0440 (8)	−0.0105 (7)	−0.0091 (7)	0.0027 (6)
C7	0.0729 (12)	0.0473 (9)	0.0544 (10)	−0.0203 (9)	−0.0144 (9)	0.0018 (8)
C8	0.0602 (11)	0.0577 (10)	0.0616 (11)	−0.0278 (9)	−0.0164 (9)	0.0163 (9)
C8A	0.0445 (9)	0.0590 (10)	0.0519 (9)	−0.0130 (8)	−0.0087 (7)	0.0170 (8)
C9	0.0393 (9)	0.0777 (14)	0.0696 (12)	−0.0148 (9)	−0.0036 (9)	0.0271 (11)
C10	0.0381 (9)	0.0847 (14)	0.0579 (11)	0.0021 (9)	0.0074 (8)	0.0213 (10)
C10A	0.0378 (8)	0.0673 (11)	0.0428 (8)	0.0041 (7)	0.0000 (7)	0.0104 (8)
C11	0.0441 (9)	0.0721 (12)	0.0451 (9)	0.0104 (8)	0.0040 (7)	−0.0029 (8)
C12	0.0425 (8)	0.0574 (10)	0.0513 (9)	0.0077 (7)	−0.0042 (7)	−0.0094 (8)
C12A	0.0325 (7)	0.0455 (8)	0.0461 (8)	0.0032 (6)	−0.0066 (6)	−0.0030 (6)
C13	0.0386 (7)	0.0398 (8)	0.0583 (10)	0.0002 (6)	−0.0051 (7)	−0.0029 (7)
C14	0.0506 (10)	0.0429 (8)	0.0555 (10)	−0.0090 (7)	−0.0018 (7)	0.0062 (7)
C15	0.0470 (9)	0.0486 (9)	0.0400 (8)	−0.0078 (7)	0.0002 (7)	−0.0005 (7)
C16	0.0388 (7)	0.0407 (7)	0.0410 (7)	−0.0048 (6)	−0.0030 (6)	−0.0034 (6)
C16A	0.0312 (6)	0.0423 (7)	0.0394 (7)	−0.0015 (5)	−0.0044 (6)	0.0006 (6)
C16B	0.0339 (7)	0.0492 (8)	0.0426 (8)	−0.0024 (6)	−0.0039 (6)	0.0046 (7)
C16C	0.0407 (8)	0.0477 (8)	0.0400 (7)	−0.0086 (6)	−0.0034 (6)	0.0076 (6)
C16D	0.0454 (8)	0.0399 (7)	0.0381 (7)	−0.0054 (6)	−0.0051 (6)	0.0049 (6)
C16E	0.0407 (8)	0.0364 (7)	0.0361 (7)	−0.0004 (6)	−0.0032 (6)	0.0040 (5)
C17	0.0384 (9)	0.0533 (10)	0.0688 (12)	0.0062 (7)	0.0084 (8)	0.0011 (9)
C18	0.0686 (12)	0.0554 (11)	0.0536 (10)	0.0084 (9)	0.0063 (9)	−0.0011 (8)
C19	0.0542 (10)	0.0518 (9)	0.0491 (9)	0.0061 (8)	−0.0056 (8)	0.0028 (8)
C20	0.0493 (9)	0.0504 (9)	0.0597 (10)	0.0016 (7)	−0.0030 (8)	0.0023 (8)
C21	0.0654 (11)	0.0445 (9)	0.0669 (12)	0.0019 (8)	−0.0108 (10)	0.0022 (9)
C22	0.0484 (9)	0.0460 (9)	0.0827 (14)	0.0006 (7)	−0.0065 (9)	−0.0102 (9)
C23	0.0560 (11)	0.0451 (10)	0.118 (2)	−0.0010 (8)	−0.0014 (13)	−0.0146 (11)
C24	0.0589 (12)	0.0510 (10)	0.1026 (18)	−0.0013 (9)	−0.0069 (11)	−0.0259 (12)

Geometric parameters (Å, º)

O1—C4	1.374 (2)	C10A—C16B	1.409 (2)
O1—C17	1.443 (2)	C10A—C11	1.428 (3)
O2—C13	1.382 (2)	C11—C12	1.360 (3)
O2—C24	1.434 (3)	C12—C12A	1.433 (2)
C1—C2	1.366 (2)	C12A—C13	1.414 (2)
C1—C16E	1.414 (2)	C12A—C16A	1.418 (2)
C2—C3	1.397 (2)	C13—C14	1.363 (3)
C3—C4	1.370 (2)	C14—C15	1.404 (3)
C4—C4A	1.421 (2)	C15—C16	1.372 (2)
C4A—C16E	1.417 (2)	C16—C16A	1.410 (2)
C4A—C5	1.434 (2)	C16A—C16B	1.450 (2)
C5—C6	1.348 (3)	C16B—C16C	1.442 (2)
C6—C6A	1.428 (3)	C16C—C16D	1.441 (2)
C6A—C16D	1.413 (2)	C16D—C16E	1.453 (2)
C6A—C7	1.428 (3)	C17—C18	1.512 (3)
C7—C8	1.349 (3)	C18—C19	1.533 (3)
C8—C8A	1.424 (3)	C19—C20	1.523 (3)
C8A—C16C	1.420 (2)	C20—C21	1.523 (3)
C8A—C9	1.428 (3)	C21—C22	1.499 (3)
C9—C10	1.350 (3)	C22—C23	1.548 (3)
C10—C10A	1.424 (3)	C23—C24	1.480 (3)
C4—O1—C17	117.12 (13)	C16A—C12A—C12	119.42 (16)
C13—O2—C24	114.87 (14)	C14—C13—O2	120.09 (17)
C2—C1—C16E	120.84 (15)	C14—C13—C12A	121.24 (16)
C1—C2—C3	121.34 (16)	O2—C13—C12A	118.59 (16)
C4—C3—C2	119.42 (16)	C13—C14—C15	119.41 (16)
C3—C4—O1	123.72 (16)	C16—C15—C14	120.82 (16)
C3—C4—C4A	120.39 (15)	C15—C16—C16A	120.47 (15)
O1—C4—C4A	115.88 (15)	C16—C16A—C12A	118.80 (14)
C16E—C4A—C4	119.34 (14)	C16—C16A—C16B	122.29 (14)
C16E—C4A—C5	119.71 (15)	C12A—C16A—C16B	118.61 (14)
C4—C4A—C5	120.85 (15)	C10A—C16B—C16C	118.06 (15)
C6—C5—C4A	120.16 (17)	C10A—C16B—C16A	118.27 (15)
C5—C6—C6A	121.63 (16)	C16C—C16B—C16A	123.39 (15)
C16D—C6A—C7	119.16 (18)	C8A—C16C—C16D	118.28 (16)
C16D—C6A—C6	119.39 (15)	C8A—C16C—C16B	117.35 (16)
C7—C6A—C6	121.43 (18)	C16D—C16C—C16B	124.35 (14)
C8—C7—C6A	120.94 (19)	C6A—C16D—C16C	118.55 (15)
C7—C8—C8A	121.20 (17)	C6A—C16D—C16E	118.05 (15)
C16C—C8A—C8	118.64 (18)	C16C—C16D—C16E	123.10 (14)
C16C—C8A—C9	118.37 (18)	C1—C16E—C4A	117.85 (13)
C8—C8A—C9	122.91 (17)	C1—C16E—C16D	123.39 (14)
C10—C9—C8A	120.94 (17)	C4A—C16E—C16D	118.61 (14)
C9—C10—C10A	120.56 (19)	O1—C17—C18	113.29 (16)
C16B—C10A—C10	118.87 (19)	C17—C18—C19	118.65 (17)
C16B—C10A—C11	118.91 (16)	C20—C19—C18	113.13 (16)
C10—C10A—C11	122.19 (18)	C21—C20—C19	115.26 (16)
C12—C11—C10A	121.10 (17)	C22—C21—C20	115.35 (17)
C11—C12—C12A	120.22 (17)	C21—C22—C23	109.97 (19)
C13—C12A—C16A	118.63 (15)	C24—C23—C22	117.5 (2)
C13—C12A—C12	121.74 (16)	O2—C24—C23	115.9 (2)
C16E—C1—C2—C3	3.1 (3)	C12—C12A—C16A—C16B	−3.5 (2)
C1—C2—C3—C4	−1.8 (3)	C10—C10A—C16B—C16C	−16.4 (2)
C2—C3—C4—O1	175.90 (16)	C11—C10A—C16B—C16C	165.55 (15)
C2—C3—C4—C4A	−5.1 (3)	C10—C10A—C16B—C16A	157.72 (16)
C17—O1—C4—C3	−37.4 (3)	C11—C10A—C16B—C16A	−20.4 (2)
C17—O1—C4—C4A	143.53 (16)	C16—C16A—C16B—C10A	−155.39 (15)
C3—C4—C4A—C16E	10.7 (2)	C12A—C16A—C16B—C10A	18.2 (2)
O1—C4—C4A—C16E	−170.23 (14)	C16—C16A—C16B—C16C	18.4 (2)
C3—C4—C4A—C5	−165.59 (16)	C12A—C16A—C16B—C16C	−168.01 (14)
O1—C4—C4A—C5	13.5 (2)	C8—C8A—C16C—C16D	−17.7 (2)
C16E—C4A—C5—C6	−4.3 (3)	C9—C8A—C16C—C16D	159.12 (16)
C4—C4A—C5—C6	171.96 (18)	C8—C8A—C16C—C16B	163.88 (16)
C4A—C5—C6—C6A	7.9 (3)	C9—C8A—C16C—C16B	−19.3 (2)
C5—C6—C6A—C16D	1.7 (3)	C10A—C16B—C16C—C8A	27.9 (2)
C5—C6—C6A—C7	−176.88 (18)	C16A—C16B—C16C—C8A	−145.83 (16)
C16D—C6A—C7—C8	−4.3 (3)	C10A—C16B—C16C—C16D	−150.36 (16)
C6—C6A—C7—C8	174.28 (18)	C16A—C16B—C16C—C16D	35.9 (2)
C6A—C7—C8—C8A	7.5 (3)	C7—C6A—C16D—C16C	−9.8 (2)
C7—C8—C8A—C16C	3.8 (3)	C6—C6A—C16D—C16C	171.57 (16)
C7—C8—C8A—C9	−172.92 (19)	C7—C6A—C16D—C16E	164.12 (16)
C16C—C8A—C9—C10	−1.2 (3)	C6—C6A—C16D—C16E	−14.5 (2)
C8—C8A—C9—C10	175.55 (19)	C8A—C16C—C16D—C6A	20.7 (2)
C8A—C9—C10—C10A	13.3 (3)	C16B—C16C—C16D—C6A	−161.05 (16)
C9—C10—C10A—C16B	−4.3 (3)	C8A—C16C—C16D—C16E	−152.92 (16)
C9—C10—C10A—C11	173.73 (18)	C16B—C16C—C16D—C16E	25.4 (2)
C16B—C10A—C11—C12	7.7 (3)	C2—C1—C16E—C4A	2.6 (2)
C10—C10A—C11—C12	−170.30 (18)	C2—C1—C16E—C16D	177.99 (15)
C10A—C11—C12—C12A	7.4 (3)	C4—C4A—C16E—C1	−9.2 (2)
C11—C12—C12A—C13	165.37 (17)	C5—C4A—C16E—C1	167.08 (15)
C11—C12—C12A—C16A	−9.3 (2)	C4—C4A—C16E—C16D	175.09 (14)
C24—O2—C13—C14	−94.4 (2)	C5—C4A—C16E—C16D	−8.6 (2)
C24—O2—C13—C12A	88.8 (2)	C6A—C16D—C16E—C1	−157.62 (15)
C16A—C12A—C13—C14	9.2 (2)	C16C—C16D—C16E—C1	16.0 (2)
C12—C12A—C13—C14	−165.53 (16)	C6A—C16D—C16E—C4A	17.8 (2)
C16A—C12A—C13—O2	−174.10 (13)	C16C—C16D—C16E—C4A	−168.59 (15)
C12—C12A—C13—O2	11.1 (2)	C4—O1—C17—C18	−72.9 (2)
O2—C13—C14—C15	176.34 (16)	O1—C17—C18—C19	78.5 (2)
C12A—C13—C14—C15	−7.0 (3)	C17—C18—C19—C20	67.6 (2)
C13—C14—C15—C16	0.1 (3)	C18—C19—C20—C21	169.03 (18)
C14—C15—C16—C16A	4.4 (2)	C19—C20—C21—C22	76.7 (2)
C15—C16—C16A—C12A	−2.1 (2)	C20—C21—C22—C23	−178.75 (18)
C15—C16—C16A—C16B	171.57 (15)	C21—C22—C23—C24	164.1 (2)
C13—C12A—C16A—C16	−4.6 (2)	C13—O2—C24—C23	66.0 (3)
C12—C12A—C16A—C16	170.31 (14)	C22—C23—C24—O2	−88.4 (3)
C13—C12A—C16A—C16B	−178.41 (14)