organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

anti-2,2,3,3,6,6,7,7,10,10,11,11,14,14,15,15-Hexadeca­methyl-2,3,6,7,10,11,14,15-octa­sila­penta­cyclo­[10.4.2.24,9.05,8.013,16]icosa-1(17),4,8,12(18),13(16),19-hexa­ene

aDepartment of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
*Correspondence e-mail: kyushin@gunma-u.ac.jp

(Received 5 December 2012; accepted 25 January 2013; online 6 February 2013)

The title compound, C28H52Si8, was synthesized by condensation of two mol­ecules of 1,2,3,4-tetra­kis­(chloro­dimethyl­sil­yl)benzene with lithium. The 3,4-disila-1,2-benzocyclo­butene rings in the centrosymmetric molecule are bridged by 1,1,2,2-tetra­methyl­disilanylene chains with an anti conformation. The benzene rings are deformed by fusion with a 3,4-disilacyclo­butene ring resulting in a slight boat conformation. Two Si—C bonds are bent to reduce the steric repulsion between the methyl groups on the two Si atoms and the methyl groups on another two Si atoms.

Related literature

For structures of cyclo­phanes bridged by tetra­methyl­disilanylene chains, see: Sakurai et al. (1986[Sakurai, H., Hoshi, S., Kamiya, A., Hosomi, A. & Kabuto, C. (1986). Chem. Lett. pp. 1781-1784.]); Sekiguchi et al. (1989[Sekiguchi, A., Yatabe, T., Kabuto, C. & Sakurai, H. (1989). Angew. Chem. Int. Ed. Engl. 28, 757-758.]).

[Scheme 1]

Experimental

Crystal data
  • C28H52Si8

  • Mr = 613.42

  • Monoclinic, P 21 /n

  • a = 7.9801 (8) Å

  • b = 18.9087 (14) Å

  • c = 12.6222 (10) Å

  • β = 104.2788 (9)°

  • V = 1845.8 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.31 mm−1

  • T = 203 K

  • 0.25 × 0.25 × 0.25 mm

Data collection
  • Rigaku R-AXIS IV Imaging Plate diffractometer

  • Absorption correction: multi-scan (REQAB; Jacobson, 1998[Jacobson, R. (1998). REQAB. Private communication to the Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.927, Tmax = 0.927

  • 9672 measured reflections

  • 3096 independent reflections

  • 3076 reflections with I > 2σ(I)

  • Rint = 0.016

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.076

  • S = 1.11

  • 3096 reflections

  • 171 parameters

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.26 e Å−3

Data collection: CrystalClear (Rigaku, 2003[Rigaku (2003). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR2004 (Burla et al., 2005[Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381-388.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: SHELXL97 and Yadokari-XG 2009 (Kabuto et al., 2009[Kabuto, C., Akine, S., Nemoto, T. & Kwon, E. (2009). J. Cryst. Soc. Jpn, 51, 218-224.]).

Supporting information


Comment top

Cyclophanes have been studied from the viewpoints of unique structures and interaction among aromatic rings. Some examples of cyclophanes bridged by silicon chains have so far been reported. [2.2]paracyclophane bridged by two 1,1,2,2-tetramethyldisilanylene chains has been synthesized, and its electronic properties have been reported (Sakurai et al., 1986). Also, [2.2.2](1,3,5)cyclophane bridged by three 1,1,2,2-tetramethyldisilanylene chains has been synthesized (Sekiguchi et al., 1989). Although cyclophanes bridged by silicon chains are attractive compounds, their studies have not further developed because of difficulty of synthesis. We report herein synthesis of a silicon-bridged [2.2]paracyclophane, in which two benzene rings are fused with 3,4-disilacyclobutene rings, and discuss the structural features of this compound.

The condensation of two molecules of 1,2,3,4-tetrakis(chlorodimethylsilyl)benzene with lithium in THF gave 1 in 2% yield (Fig. 1). The structure of 1 was determined by X-ray crystallography (Fig. 2). The molecule lies on an inversion center, and one half of the molecule corresponds to the asymmetric unit. Two 3,4-disila-1,2-benzocyclobutene rings are bridged by 1,1,2,2-tetramethyldisilanylene chains with an anti structure. The anti structure is favorable to avoid the steric hindrance among methyl groups on the 3,4-disilacyclobutene rings.

The benzene rings have a deformed structure due to fusion with a 3,4-disilacyclobutene ring (Fig. 3). The C—C bond is elongated in the order of C5—C6i (1.390 (2) Å), C1—C5 (1.399 (2) Å) (or C2i—C6i (1.396 (2) Å)), C1—C4 (1.417 (2) Å) (or C2i—C3i (1.418 (2) Å)) and C4—C3i (1.431 (2) Å). The Si1—C1—C4 and Si2i—C2i—C3i bond angles are large (127.24 (11) and 127.03 (11)°, respectively), and the Si1—C1—C5 and Si2i—C2i—C6i bond angles are small (115.53 (11) and 115.79 (11)°, respectively). As a result, two benzene rings are partially overlapped as shown in Fig. 4. This deformation of the bond angles is caused by the steric repulsion between the methyl groups on the Si1 and Si2i atoms and the methyl groups on the Si3 and Si4 atoms. This steric repulsion also makes the Si3—Si4 bond short (2.3245 (7) Å) compared with the standard Si—Si bond (2.34 Å).

The benzene rings are also deformed by the cyclophane structure (Fig. 3). The benzene rings are not planar but have a slight boat conformation. The dihedral angle between the C4—C5—C6i—C3i plane and the C1—C4—C5 (or C2i—C3i—C6i) plane is 5.8° (or 5.2°). The Si1—C1 and Si2i—C2i bonds are further tilted from the C4—C5—C6i—C3i plane with the angles of 16.8 and 15.4°. The distance between the C4—C5—C6i—C3i and C3—C6—C5i—C4i planes is 3.473 Å, and the distance between the C1 and C2 atoms is 3.383 Å. These structural features are similar to those of 1,1,2,2,9,9,10,10-octamethyl-1,2,9,10-tetrasila[2.2]paracyclophane (2) (Sakurai et al., 1986) as shown in Fig. 3.

Related literature top

For structures of cyclophanes bridged by tetramethyldisilanylene chains, see: Sakurai et al. (1986); Sekiguchi et al. (1989).

Experimental top

All operations except for Kugelrohr distillation were carried out in a glovebox. A mixture of 1,2,3,4-tetrakis(chlorodimethylsilyl)benzene (0.200 g, 0.446 mmol) and lithium (13.0 mg, 1.87 mmol) in THF (25 ml) was stirred at room temperature for 14 h. After removal of the solvent, the residue was dissolved in toluene, and insoluble materials were filtered off. The solvent was removed under reduced pressure. Kugelrohr distillation (300 °C/0.9 mm Hg) of the residue gave a colorless solid. The solid was recrystallized from hexane to give 1 (3 mg, 2%) as colorless crystals. Single crystals were obtained from hexane by slow evaporation.

M.p.: 328–330 °C. 1H NMR (600 MHz, C6D6): δ 0.42 (s, 12H), 0.51 (s, 12H), 0.60 (s, 12H), 0.67 (s, 12H), 6.66 (s, 4H). 13C NMR (151 MHz, C6D6): δ -2.6, -1.3, -0.9, 136.0, 143.2, 160.2. 29Si NMR (119 MHz, C6D6): δ -18.1, -3.7. IR (KBr): 2960, 2930, 2900, 2850, 1260, 1250, 1100, 1080, 1020, 800, 750 cm-1. MS (EI, 70 eV): m/z 612 (M+, 29), 539 (23), 465 (18), 291 (15), 73 (100).

Refinement top

All hydrogen atoms were generated at calculated positions and refined as riding atoms with C—H = 0.95 (phenyl) or 0.98 (methyl) Å and Uiso(H) = 1.2Ueq(phenyl C) or 1.5Ueq(methyl C).

Computing details top

Data collection: CrystalClear (Rigaku, 2003); cell refinement: CrystalClear (Rigaku, 2003); data reduction: CrystalClear (Rigaku, 2003); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and Yadokari-XG 2009 (Kabuto et al., 2009).

Figures top
Fig. 1. Synthesis of 1.

Fig. 2. The molecular structure of 1, showing 50% probability displacement ellipsoids. [Symmetry code: (i) –x + 1, –y, –z + 1.]

Fig. 3. Comparison of the structures of 1 and 2.

Fig. 4. Top view of 1, showing 50% probability displacement ellipsoids. [Symmetry code: (i) –x + 1, –y, –z + 1.]
anti-2,2,3,3,6,6,7,7,10,10,11,11,14,14,15,15-Hexadecamethyl-2,3,6,7,10,11,14,15-octasilapentacyclo[10.4.2.24,9.05,8.013,16]icosa-1(17),4,8,12 (18),13 (16),19-hexaene top
Crystal data top
C28H52Si8F(000) = 664
Mr = 613.42Dx = 1.104 Mg m3
Monoclinic, P21/nMelting point = 328–330 K
Hall symbol: -P 2ynMo Kα radiation, λ = 0.71073 Å
a = 7.9801 (8) ÅCell parameters from 11187 reflections
b = 18.9087 (14) Åθ = 1.7–28.3°
c = 12.6222 (10) ŵ = 0.31 mm1
β = 104.2788 (9)°T = 203 K
V = 1845.8 (3) Å3Prism, colourless
Z = 20.25 × 0.25 × 0.25 mm
Data collection top
Rigaku R-AXIS IV imaging plate
diffractometer
3096 independent reflections
Radiation source: rotating anode3076 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.016
Detector resolution: 10.00 pixels mm-1θmax = 25.0°, θmin = 2.0°
ω scansh = 99
Absorption correction: multi-scan
(REQAB; Jacobson, 1998)
k = 2219
Tmin = 0.927, Tmax = 0.927l = 1515
9672 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.076H-atom parameters constrained
S = 1.11 w = 1/[σ2(Fo2) + (0.0349P)2 + 0.7873P]
where P = (Fo2 + 2Fc2)/3
3096 reflections(Δ/σ)max = 0.021
171 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C28H52Si8V = 1845.8 (3) Å3
Mr = 613.42Z = 2
Monoclinic, P21/nMo Kα radiation
a = 7.9801 (8) ŵ = 0.31 mm1
b = 18.9087 (14) ÅT = 203 K
c = 12.6222 (10) Å0.25 × 0.25 × 0.25 mm
β = 104.2788 (9)°
Data collection top
Rigaku R-AXIS IV imaging plate
diffractometer
3096 independent reflections
Absorption correction: multi-scan
(REQAB; Jacobson, 1998)
3076 reflections with I > 2σ(I)
Tmin = 0.927, Tmax = 0.927Rint = 0.016
9672 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.076H-atom parameters constrained
S = 1.11Δρmax = 0.25 e Å3
3096 reflectionsΔρmin = 0.25 e Å3
171 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.

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 > 2σ(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
xyzUiso*/Ueq
Si10.18531 (5)0.13135 (2)0.45683 (3)0.02369 (12)
Si20.43507 (5)0.17209 (2)0.40399 (3)0.02186 (12)
Si30.50467 (6)0.03139 (2)0.81537 (3)0.02614 (12)
Si40.36313 (6)0.07548 (2)0.76574 (3)0.02856 (13)
C10.24730 (19)0.04152 (8)0.52049 (12)0.0218 (3)
C20.58255 (18)0.09258 (7)0.41846 (11)0.0202 (3)
C30.58234 (19)0.03950 (7)0.33902 (11)0.0209 (3)
C40.33293 (19)0.02681 (7)0.63061 (12)0.0212 (3)
C50.2347 (2)0.01465 (8)0.44684 (12)0.0245 (3)
C60.6830 (2)0.07907 (8)0.52380 (12)0.0238 (3)
C70.1117 (3)0.19586 (9)0.54917 (15)0.0412 (4)
C80.0026 (2)0.12151 (10)0.33167 (14)0.0354 (4)
C90.5452 (2)0.24491 (9)0.49722 (15)0.0384 (4)
C100.3789 (2)0.21016 (9)0.26238 (13)0.0361 (4)
C110.4144 (3)0.09537 (10)0.90036 (13)0.0402 (4)
C120.7449 (2)0.02692 (11)0.86886 (15)0.0452 (5)
C130.1573 (3)0.09331 (11)0.80715 (16)0.0498 (5)
C140.5025 (3)0.15680 (10)0.78452 (15)0.0530 (6)
H10.16810.00860.37480.029*
H20.69550.11490.57680.029*
H30.08010.24020.51070.062*
H40.20480.20410.61370.062*
H50.01240.17670.57070.062*
H60.09460.09880.35120.053*
H70.04010.09280.27810.053*
H80.03220.16780.30100.053*
H90.65340.25700.47960.058*
H100.56820.22910.57250.058*
H110.47090.28620.48760.058*
H120.31410.25360.26190.054*
H130.30930.17650.21230.054*
H140.48420.22010.23980.054*
H150.47270.14060.90230.060*
H160.29160.10160.86860.060*
H170.43230.07710.97410.060*
H180.77270.01300.94520.068*
H190.79190.00760.82710.068*
H200.79470.07300.86200.068*
H210.18410.11040.88190.075*
H220.09060.05000.80190.075*
H230.09060.12870.75910.075*
H240.43780.19580.74400.079*
H250.60450.14780.75780.079*
H260.53730.16890.86150.079*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0281 (2)0.0210 (2)0.0237 (2)0.00390 (15)0.00974 (17)0.00293 (15)
Si20.0282 (2)0.0175 (2)0.0200 (2)0.00024 (15)0.00618 (17)0.00197 (14)
Si30.0354 (3)0.0275 (2)0.0153 (2)0.00299 (17)0.00606 (18)0.00042 (15)
Si40.0461 (3)0.0221 (2)0.0199 (2)0.00391 (18)0.01276 (19)0.00352 (16)
C10.0220 (8)0.0228 (7)0.0226 (7)0.0009 (5)0.0093 (6)0.0020 (6)
C20.0225 (8)0.0200 (7)0.0201 (7)0.0035 (5)0.0088 (6)0.0019 (5)
C30.0235 (8)0.0218 (7)0.0186 (7)0.0048 (5)0.0075 (6)0.0015 (5)
C40.0262 (8)0.0200 (7)0.0197 (7)0.0041 (5)0.0100 (6)0.0012 (5)
C50.0278 (8)0.0277 (8)0.0170 (7)0.0010 (6)0.0036 (6)0.0019 (6)
C60.0298 (9)0.0226 (8)0.0193 (7)0.0012 (6)0.0067 (6)0.0031 (5)
C70.0567 (12)0.0318 (9)0.0415 (10)0.0143 (8)0.0239 (9)0.0031 (8)
C80.0297 (9)0.0378 (10)0.0374 (9)0.0032 (7)0.0056 (7)0.0081 (7)
C90.0510 (11)0.0228 (8)0.0390 (9)0.0052 (7)0.0062 (8)0.0034 (7)
C100.0478 (11)0.0330 (9)0.0282 (9)0.0084 (7)0.0108 (8)0.0100 (7)
C110.0630 (13)0.0371 (10)0.0242 (8)0.0023 (8)0.0181 (8)0.0047 (7)
C120.0414 (11)0.0606 (13)0.0306 (9)0.0043 (9)0.0030 (8)0.0091 (8)
C130.0696 (14)0.0514 (12)0.0374 (10)0.0154 (10)0.0303 (10)0.0010 (9)
C140.0894 (17)0.0341 (10)0.0328 (10)0.0244 (10)0.0104 (10)0.0051 (8)
Geometric parameters (Å, º) top
Si1—Si22.3805 (6)C7—H40.9700
Si1—C11.8919 (15)C7—H50.9700
Si1—C71.8785 (17)C8—H60.9700
Si1—C81.8762 (18)C8—H70.9700
Si2—C21.8902 (15)C8—H80.9700
Si2—C91.8824 (17)C9—H90.9700
Si2—C101.8758 (16)C9—H100.9700
Si3—Si42.3245 (7)C9—H110.9700
Si3—C111.8746 (17)C10—H120.9700
Si3—C121.871 (2)C10—H130.9700
Si3—C3i1.9067 (15)C10—H140.9700
Si4—C41.9004 (15)C11—H150.9700
Si4—C131.873 (2)C11—H160.9700
Si4—C141.8781 (19)C11—H170.9700
C1—C41.417 (2)C12—H180.9700
C1—C51.399 (2)C12—H190.9700
C2—C31.418 (2)C12—H200.9700
C2—C61.396 (2)C13—H210.9700
C3—C4i1.431 (2)C13—H220.9700
C5—C6i1.390 (2)C13—H230.9700
C5—H10.9400C14—H240.9700
C6—H20.9400C14—H250.9700
C7—H30.9700C14—H260.9700
Si2—Si1—C1105.08 (5)H3—C7—H4109.5
Si2—Si1—C7112.03 (7)H3—C7—H5109.5
Si2—Si1—C8109.07 (6)H4—C7—H5109.5
C1—Si1—C7114.11 (7)Si1—C8—H6109.5
C1—Si1—C8109.64 (7)Si1—C8—H7109.5
C7—Si1—C8106.85 (9)Si1—C8—H8109.5
Si1—Si2—C2105.07 (5)H6—C8—H7109.5
Si1—Si2—C9110.84 (6)H6—C8—H8109.5
Si1—Si2—C10111.80 (6)H7—C8—H8109.5
C2—Si2—C9109.74 (8)Si2—C9—H9109.5
C2—Si2—C10113.21 (7)Si2—C9—H10109.5
C9—Si2—C10106.26 (8)Si2—C9—H11109.5
Si4—Si3—C11119.05 (7)H9—C9—H10109.5
Si4—Si3—C12116.39 (7)H9—C9—H11109.5
Si4—Si3—C3i76.36 (5)H10—C9—H11109.5
C11—Si3—C12109.08 (9)Si2—C10—H12109.5
C11—Si3—C3i116.01 (7)Si2—C10—H13109.5
C12—Si3—C3i117.06 (7)Si2—C10—H14109.5
Si3—Si4—C476.50 (5)H12—C10—H13109.5
Si3—Si4—C13118.85 (7)H12—C10—H14109.5
Si3—Si4—C14116.39 (8)H13—C10—H14109.5
C4—Si4—C13114.32 (8)Si3—C11—H15109.5
C4—Si4—C14116.73 (8)Si3—C11—H16109.5
C13—Si4—C14110.50 (11)Si3—C11—H17109.5
Si1—C1—C4127.24 (11)H15—C11—H16109.5
Si1—C1—C5115.53 (11)H15—C11—H17109.5
C4—C1—C5116.18 (13)H16—C11—H17109.5
Si2—C2—C3127.03 (11)Si3—C12—H18109.5
Si2—C2—C6115.79 (11)Si3—C12—H19109.5
C3—C2—C6116.36 (13)Si3—C12—H20109.5
Si3i—C3—C2135.73 (11)H18—C12—H19109.5
Si3i—C3—C4i103.43 (10)H18—C12—H20109.5
C2—C3—C4i120.82 (13)H19—C12—H20109.5
Si4—C4—C1135.16 (11)Si4—C13—H21109.5
Si4—C4—C3i103.70 (10)Si4—C13—H22109.5
C1—C4—C3i121.09 (13)Si4—C13—H23109.5
C1—C5—C6i122.44 (14)H21—C13—H22109.5
C1—C5—H1118.8H21—C13—H23109.5
C6i—C5—H1118.8H22—C13—H23109.5
C2—C6—C5i122.46 (13)Si4—C14—H24109.5
C2—C6—H2118.8Si4—C14—H25109.5
C5i—C6—H2118.8Si4—C14—H26109.5
Si1—C7—H3109.5H24—C14—H25109.5
Si1—C7—H4109.5H24—C14—H26109.5
Si1—C7—H5109.5H25—C14—H26109.5
C1—Si1—Si2—C211.34 (7)C12—Si3—Si4—C4113.08 (8)
C1—Si1—Si2—C9107.13 (8)C12—Si3—Si4—C13136.36 (10)
C1—Si1—Si2—C10134.52 (8)C12—Si3—Si4—C140.33 (10)
C7—Si1—Si2—C2135.78 (8)C3i—Si3—Si4—C40.64 (6)
C7—Si1—Si2—C917.31 (9)C3i—Si3—Si4—C13109.93 (9)
C7—Si1—Si2—C10101.04 (9)C3i—Si3—Si4—C14114.04 (8)
C8—Si1—Si2—C2106.14 (8)Si3—Si4—C4—C1178.26 (16)
C8—Si1—Si2—C9135.39 (9)Si3—Si4—C4—C3i0.85 (8)
C8—Si1—Si2—C1017.04 (9)C13—Si4—C4—C162.41 (17)
Si2—Si1—C1—C485.99 (13)C13—Si4—C4—C3i115.00 (11)
Si2—Si1—C1—C581.76 (11)C14—Si4—C4—C168.73 (18)
C7—Si1—C1—C437.12 (16)C14—Si4—C4—C3i113.86 (12)
C7—Si1—C1—C5155.13 (12)Si1—C1—C4—Si421.9 (2)
C8—Si1—C1—C4156.92 (13)Si1—C1—C4—C3i160.99 (11)
C8—Si1—C1—C535.33 (13)C5—C1—C4—Si4170.37 (12)
Si1—Si2—C2—C386.84 (12)C5—C1—C4—C3i6.7 (2)
Si1—Si2—C2—C682.38 (11)Si1—C1—C5—C6i162.33 (12)
C9—Si2—C2—C3153.95 (13)C4—C1—C5—C6i6.8 (2)
C9—Si2—C2—C636.83 (13)Si2—C2—C3—Si3i18.9 (2)
C10—Si2—C2—C335.43 (15)Si2—C2—C3—C4i163.08 (11)
C10—Si2—C2—C6155.35 (11)C6—C2—C3—Si3i171.94 (12)
C11—Si3—Si4—C4113.06 (8)C6—C2—C3—C4i6.1 (2)
C11—Si3—Si4—C132.49 (11)Si2—C2—C6—C5i164.24 (12)
C11—Si3—Si4—C14133.53 (10)C3—C2—C6—C5i6.2 (2)
Symmetry code: (i) x+1, y, z+1.

Experimental details

Crystal data
Chemical formulaC28H52Si8
Mr613.42
Crystal system, space groupMonoclinic, P21/n
Temperature (K)203
a, b, c (Å)7.9801 (8), 18.9087 (14), 12.6222 (10)
β (°) 104.2788 (9)
V3)1845.8 (3)
Z2
Radiation typeMo Kα
µ (mm1)0.31
Crystal size (mm)0.25 × 0.25 × 0.25
Data collection
DiffractometerRigaku R-AXIS IV imaging plate
diffractometer
Absorption correctionMulti-scan
(REQAB; Jacobson, 1998)
Tmin, Tmax0.927, 0.927
No. of measured, independent and
observed [I > 2σ(I)] reflections
9672, 3096, 3076
Rint0.016
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.076, 1.11
No. of reflections3096
No. of parameters171
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.25

Computer programs: CrystalClear (Rigaku, 2003), SIR2004 (Burla et al., 2005), ORTEP-3 for Windows (Farrugia, 2012), SHELXL97 (Sheldrick, 2008) and Yadokari-XG 2009 (Kabuto et al., 2009).

 

Acknowledgements

This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan and the Japan Society for the Promotion of Science. This work was also supported by the Element Innovation Project of Gunma University.

References

First citationBurla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381–388.  Web of Science CrossRef CAS IUCr Journals
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals
First citationJacobson, R. (1998). REQAB. Private communication to the Rigaku Corporation, Tokyo, Japan.
First citationKabuto, C., Akine, S., Nemoto, T. & Kwon, E. (2009). J. Cryst. Soc. Jpn, 51, 218–224.  CrossRef
First citationRigaku (2003). CrystalClear. Rigaku Corporation, Tokyo, Japan.
First citationSakurai, H., Hoshi, S., Kamiya, A., Hosomi, A. & Kabuto, C. (1986). Chem. Lett. pp. 1781–1784.  CrossRef Web of Science
First citationSekiguchi, A., Yatabe, T., Kabuto, C. & Sakurai, H. (1989). Angew. Chem. Int. Ed. Engl. 28, 757–758.  CSD CrossRef Web of Science
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals

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