A mol­ecule with a C1-homobasketane framework

Tomura, M.; Yamashita, Y.

doi:10.1107/S0108270101002761

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A molecule with a C₁-homobasketane framework

M. Tomura and Y. Yamashita

The title compound, 6-(1,3-benzodithiol-2-ylidene)-5,7-dimethyl-1,2-diphenylpentacyclo[5.4.0.0^2,5.0^3,11.0^4,8]undecane, C₃₂H₂₈S₂, with a C₁-homobasketane framework, crystallizes in the P $\overline 1$ space group with one molecule in the asymmetric unit. The two cyclobutane rings in the cage are in a puckered conformation. Due to the enhanced through-bond interaction of the phenyl π systems involving a strained σ bond, the (Ph—)C—C(—Ph) bond length is significantly extended, to 1.610 (3) Å.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101002761/bk1587sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S0108270101002761/bk1587Isup2.hkl Contains datablock I

CCDC reference: 164671

Comment top

There is considerable interest in the chemistry of highly strained polycyclic `cage' compounds and their application to solar energy storage (Ōsawa & Yonemitsu, 1992). Trishomocubanes, which are one type of cubane homologue, result from the introduction of three methylene groups into the cubane framework and have fourteen isomers (Marchand, 1989). Among these, X-ray crystal structures of only four types of isomer have been reported. We have recently synthesized the title trishomocubane, the C₁-homobasketane derivative, (I), with a 1,3-dithiole moiety as the redox part, and we present here the X-ray analysis of (I). To the best of our knowledge, this is the first example of the crystal structure determination of a molecule with a C₁-homobasketane framework. \sch

Compound (I) crystallizes in the P1 space group with one molecule in the asymmetric unit. The molecular structure of (I) is shown in Fig. 1 and selected geometric parameters are listed in Table 1. The two cyclobutane rings in the cage are in puckered conformations. The dihedral angles in the rings are -13.1 (2)° for C2—C3—C7—C6 and -20.1 (2)° for C3—C4—C8—C7. The deviations of C6 and C4 from the planes defined by the other three atoms are 0.35 (1) and 0.56 (1) Å, respectively. The bridging bond shared with the two cyclobutane rings [C3—C7 1.550 (3) Å] is almost the same length as the bonds in cyclobutanes (1.554 Å; Allen et al., 1987) and cubane [1.551 (3) Å; Fleischer, 1964].

The two phenyl groups are nearly oriented in the face-to-face conformation. The twist angles of the ring planes (Hounshell at al., 1977) to the C3—C4 bond are -88.3 (3) and 93.8 (3)° for the C21—C26 phenyl ring, and 62.2 (3) and -121.7 (2)° for the C27—C32 phenyl ring. The angle between the least-squares planes of the two phenyl groups is 75.3 (4)°.

The most remarkable features of the molecular structure of (I) are the considerably long C3—C4 [1.610 (3) Å] and C4—C5 [1.592 (3) Å] bonds. Harano et al. (1981) have proposed that elongation of C_Ph—C_Ph bonds in 1,2-diphenyl-11-azapentacyclo[5.5.0.0^2,5.0^3,12.0^4,8]dodeca-9-en-6-one derivatives, which have the same face-to-face conformation of the phenyl groups as in (I), is caused by the enhanced through-bond interaction of the phenyl π systems involving a strained σ bond. Thus, this effect brings about the elongation of the C3—C4 bond in (I).

Related literature top

For related literature, see: Akiba et al. (1978); Allen et al. (1987); Fleischer (1964); Harano et al. (1981); Marchand (1989); Moore & Bryce (1991); Tezuka et al. (1976); Ōsawa & Yonemitsu (1992).

Experimental top

Compound (I) was synthesized by a Wittig-Horner reaction of 5,7-dimethyl-1,2-diphenylpentacyclo[5.4.0.0^2,5.0^3,11.0^5,8]undecan-6-one (Tezuka et al., 1976) with 2-dimethoxyphosphinyl-4,5-benzo-1,3-dithiole (Akiba et al., 1978; Moore & Bryce, 1991). Recrystallization from dichloromethane-ethanol afforded colourless crystals of (I) suitable for X-ray analysis.

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures top

Fig. 1. The molecular structure of (I) with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms have been omitted for clarity.

5,7-dimethyl-1,2-diphenyl-6-(1,3-benzodithiol-2-ylidene) pentacyclo[5.4.0.0^2,5.0^3,11.0^4,8]undecane top

Crystal data top

C₃₂H₂₈S₂	Z = 2
M_r = 476.66	F(000) = 504
Triclinic, P1	D_x = 1.314 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 9.7467 (12) Å	Cell parameters from 25 reflections
b = 14.2911 (18) Å	θ = 14.7–15.0°
c = 9.2122 (11) Å	µ = 0.24 mm⁻¹
α = 94.091 (11)°	T = 296 K
β = 95.769 (11)°	Prismatic, colourless
γ = 70.809 (9)°	0.25 × 0.25 × 0.20 mm
V = 1204.7 (3) Å³

Data collection top

Rigaku AFC-7R diffractometer	R_int = 0.022
Radiation source: Rigaku rotating anode	θ_max = 27.5°, θ_min = 2.2°
Graphite monochromator	h = 0→12
ω/2θ scans	k = −17→18
5854 measured reflections	l = −11→11
5529 independent reflections	3 standard reflections every 150 reflections
3128 reflections with I > 2σ(I)	intensity decay: 0.3%

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)] = 0.042	Hydrogen site location: difference Fourier map
wR(F²) = 0.122	All H-atom parameters refined
S = 1.00	w = 1/[σ²(F_o²) + (0.0495P)² + 0.2116P] where P = (F_o² + 2F_c²)/3
5529 reflections	(Δ/σ)_max < 0.001
419 parameters	Δρ_max = 0.28 e Å⁻³
0 restraints	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₃₂H₂₈S₂	γ = 70.809 (9)°
M_r = 476.66	V = 1204.7 (3) Å³
Triclinic, P1	Z = 2
a = 9.7467 (12) Å	Mo Kα radiation
b = 14.2911 (18) Å	µ = 0.24 mm⁻¹
c = 9.2122 (11) Å	T = 296 K
α = 94.091 (11)°	0.25 × 0.25 × 0.20 mm
β = 95.769 (11)°

Data collection top

Rigaku AFC-7R diffractometer	R_int = 0.022
5854 measured reflections	3 standard reflections every 150 reflections
5529 independent reflections	intensity decay: 0.3%
3128 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.042	0 restraints
wR(F²) = 0.122	All H-atom parameters refined
S = 1.00	Δρ_max = 0.28 e Å⁻³
5529 reflections	Δρ_min = −0.25 e Å⁻³
419 parameters

Special details top

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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 4.7280 (0.0104) x + 3.9050 (0.0156) y + 7.0991 (0.0073) z = 4.5915 (0.0088)

* 0.0037 (0.0017) C21 * 0.0011 (0.0020) C22 * -0.0045 (0.0022) C23 * 0.0032 (0.0023) C24 * 0.0016 (0.0022) C25 * -0.0051 (0.0020) C26

Rms deviation of fitted atoms = 0.0035

7.7602 (0.0066) x + 11.5473 (0.0094) y - 2.5788 (0.0098) z = 1.5053 (0.0107)

Angle to previous plane (with approximate e.s.d.) = 75.32 (0.08)

* -0.0032 (0.0017) C27 * 0.0003 (0.0018) C28 * 0.0005 (0.0020) C29 * 0.0015 (0.0021) C30 * -0.0044 (0.0020) C31 * 0.0052 (0.0018) C32

Rms deviation of fitted atoms = 0.0031

5.1254 (0.0129) x + 11.2486 (0.0210) y + 4.2900 (0.0184) z = 6.6235 (0.0099)

Angle to previous plane (with approximate e.s.d.) = 45.77 (0.12)

* 0.0000 (0.0000) C3 * 0.0000 (0.0000) C4 * 0.0000 (0.0000) C7 0.5307 (0.0045) C8