organic compounds
1,4-Bis[4-(dimethylsilyl)phenyl]benzene
aBeijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China, bGraduate School of the Chinese Academy of Sciences, Beijing 100049, People's Republic of China, and cSchool of Chemical and Environmental Engineering, Beijing Technology and, Business University, Beijing 100037, People's Republic of China
*Correspondence e-mail: caihong@iccas.ac.cn
The complete molecule of the title compound, C22H26Si2, is generated by a crystallographic centre of symmetry. The central benzene ring makes a dihedral angle of 26.7 (4)° with the 4-(dimethylsilyl)phenyl ring. There are weak C—H⋯π interactions in the crystal structure.
Related literature
For applications of p-terphenyl derivatives as laser dyes, see: Craig et al. (1992), as light-emitting materials, see: Spiliopoulos et al. (2002) and as liquid crystalline materials, see: Yam et al. (1993). For a description of the Cambridge Structural Database, see: Allen (2002); Although p-terphenyls containing have been reported (Feng et al., 2007), their crystal structures have not yet been determined.
Experimental
Crystal data
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Refinement
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Data collection: CrystalClear (Rigaku, 2008); cell CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536810010883/fb2186sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810010883/fb2186Isup2.hkl
The reaction scheme is shown in Fig. 2. A solution of n-BuLi in hexane (1.6 M, 0.88 ml) was added dropwise to a solution of 1,4-bis(4-iodophenyl)benzene (192 mg, 0.40 mmol) in anhydrous tetrahydrofuran (THF) (80 ml) at -78 °C. After the solution having been stirred for 1 h, dimethylchlorosilane (152 mg, 1.60 mmol), also cooled to the same temperature, was added by syringe. The mixture was allowed to warm to room temperature and it was stirred overnight. After it had been quenched with saturated NaHCO3 solution, the mixture was extracted with Et2O. The organic layer was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated under reduced pressure. The mixture was recrystallized from ethanol to give 92 mg of the title product in 67% yield. The crystals were colourless needles with the average length of about 3 mm.
All the hydrogens were discernible in the difference electron density maps. Nevertheless, all the hydrogens except the hydrogen attached to Si that was refined freely, were constrained by the riding-hydrogen formalism with Uiso(H)=1.2Ueq(Caryl) or Uiso(H)=1.5Ueq(Cmethyl). The C-H distances were constrained to 0.95 and 0.98 Å for the aryl and the methyl hydrogens, respectively.
Data collection: CrystalClear (Rigaku, 2008); cell
CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C22H26Si2 | F(000) = 372 |
Mr = 346.61 | Dx = 1.130 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 347 reflections |
a = 15.143 (3) Å | θ = 2.2–27.5° |
b = 7.7263 (15) Å | µ = 0.18 mm−1 |
c = 9.1285 (18) Å | T = 173 K |
β = 107.52 (3)° | Plate, colorless |
V = 1018.5 (3) Å3 | 0.20 × 0.18 × 0.08 mm |
Z = 2 |
Rigaku Saturn724+ CCD diffractometer | 2218 independent reflections |
Radiation source: fine-focus sealed tube | 1937 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.043 |
ω scans at fixed χ = 45° | θmax = 27.0°, θmin = 2.8° |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008) | h = −19→19 |
Tmin = 0.966, Tmax = 0.986 | k = −9→9 |
7661 measured reflections | l = −7→11 |
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)] = 0.071 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.133 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.21 | w = 1/[σ2(Fo2) + (0.0276P)2 + 0.8805P] where P = (Fo2 + 2Fc2)/3 |
2218 reflections | (Δ/σ)max < 0.001 |
115 parameters | Δρmax = 0.31 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
46 constraints |
C22H26Si2 | V = 1018.5 (3) Å3 |
Mr = 346.61 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 15.143 (3) Å | µ = 0.18 mm−1 |
b = 7.7263 (15) Å | T = 173 K |
c = 9.1285 (18) Å | 0.20 × 0.18 × 0.08 mm |
β = 107.52 (3)° |
Rigaku Saturn724+ CCD diffractometer | 2218 independent reflections |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008) | 1937 reflections with I > 2σ(I) |
Tmin = 0.966, Tmax = 0.986 | Rint = 0.043 |
7661 measured reflections |
R[F2 > 2σ(F2)] = 0.071 | 0 restraints |
wR(F2) = 0.133 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.21 | Δρmax = 0.31 e Å−3 |
2218 reflections | Δρmin = −0.22 e Å−3 |
115 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Si1 | 0.35065 (5) | 0.48948 (10) | 0.54899 (8) | 0.0361 (2) | |
C1 | 0.26293 (17) | 0.4896 (3) | 0.6572 (3) | 0.0312 (5) | |
C2 | 0.17225 (18) | 0.4309 (3) | 0.5939 (3) | 0.0341 (6) | |
H2A | 0.1533 | 0.3895 | 0.4911 | 0.041* | |
C3 | 0.10866 (17) | 0.4313 (3) | 0.6768 (3) | 0.0338 (6) | |
H3A | 0.0474 | 0.3906 | 0.6299 | 0.041* | |
C4 | 0.13394 (16) | 0.4907 (3) | 0.8282 (3) | 0.0288 (5) | |
C5 | 0.22485 (18) | 0.5474 (4) | 0.8935 (3) | 0.0357 (6) | |
H5A | 0.2441 | 0.5869 | 0.9968 | 0.043* | |
C6 | 0.28736 (18) | 0.5469 (4) | 0.8098 (3) | 0.0365 (6) | |
H6A | 0.3487 | 0.5866 | 0.8572 | 0.044* | |
C7 | 0.4368 (2) | 0.3127 (5) | 0.6203 (4) | 0.0660 (11) | |
H7A | 0.4832 | 0.3164 | 0.5651 | 0.099* | |
H7B | 0.4051 | 0.2006 | 0.6028 | 0.099* | |
H7C | 0.4674 | 0.3283 | 0.7305 | 0.099* | |
C8 | 0.2933 (2) | 0.4691 (4) | 0.3401 (3) | 0.0468 (7) | |
H8A | 0.2475 | 0.5617 | 0.3060 | 0.070* | |
H8B | 0.2624 | 0.3565 | 0.3182 | 0.070* | |
H8C | 0.3398 | 0.4785 | 0.2854 | 0.070* | |
C9 | 0.06529 (16) | 0.4952 (3) | 0.9166 (3) | 0.0292 (5) | |
C10 | 0.07421 (17) | 0.6139 (3) | 1.0364 (3) | 0.0319 (6) | |
H10A | 0.1249 | 0.6924 | 1.0622 | 0.038* | |
C11 | 0.01023 (17) | 0.6186 (3) | 1.1179 (3) | 0.0322 (6) | |
H11A | 0.0178 | 0.7004 | 1.1985 | 0.039* | |
H1 | 0.3948 (17) | 0.649 (3) | 0.578 (3) | 0.036 (7)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Si1 | 0.0341 (4) | 0.0455 (5) | 0.0312 (4) | −0.0040 (3) | 0.0137 (3) | 0.0030 (3) |
C1 | 0.0319 (13) | 0.0320 (13) | 0.0314 (12) | 0.0010 (11) | 0.0119 (10) | 0.0015 (11) |
C2 | 0.0384 (14) | 0.0381 (14) | 0.0266 (12) | −0.0009 (12) | 0.0113 (11) | −0.0023 (11) |
C3 | 0.0295 (13) | 0.0366 (14) | 0.0345 (14) | −0.0019 (11) | 0.0085 (11) | −0.0027 (11) |
C4 | 0.0300 (12) | 0.0265 (12) | 0.0298 (12) | 0.0007 (10) | 0.0086 (9) | −0.0002 (10) |
C5 | 0.0359 (14) | 0.0432 (16) | 0.0281 (13) | −0.0026 (12) | 0.0100 (10) | −0.0044 (11) |
C6 | 0.0308 (13) | 0.0426 (15) | 0.0364 (14) | −0.0037 (12) | 0.0106 (11) | −0.0023 (12) |
C7 | 0.0479 (19) | 0.094 (3) | 0.065 (2) | 0.0250 (19) | 0.0313 (17) | 0.026 (2) |
C8 | 0.0528 (18) | 0.0535 (19) | 0.0370 (15) | −0.0004 (15) | 0.0178 (13) | −0.0022 (13) |
C9 | 0.0294 (12) | 0.0298 (13) | 0.0280 (11) | 0.0030 (11) | 0.0079 (9) | 0.0045 (10) |
C10 | 0.0295 (12) | 0.0337 (13) | 0.0319 (13) | −0.0033 (11) | 0.0082 (10) | −0.0032 (10) |
C11 | 0.0351 (14) | 0.0331 (14) | 0.0287 (12) | −0.0025 (11) | 0.0101 (11) | −0.0037 (10) |
Si1—C8 | 1.848 (3) | C6—H6A | 0.9500 |
Si1—C7 | 1.865 (3) | C7—H7A | 0.9800 |
Si1—C1 | 1.879 (2) | C7—H7B | 0.9800 |
Si1—H1 | 1.39 (3) | C7—H7C | 0.9800 |
C1—C2 | 1.395 (3) | C8—H8A | 0.9800 |
C1—C6 | 1.401 (3) | C8—H8B | 0.9800 |
C2—C3 | 1.393 (3) | C8—H8C | 0.9800 |
C2—H2A | 0.9500 | C9—C11i | 1.401 (3) |
C3—C4 | 1.396 (3) | C9—C10 | 1.402 (3) |
C3—H3A | 0.9500 | C10—C11 | 1.388 (3) |
C4—C5 | 1.396 (3) | C10—H10A | 0.9500 |
C4—C9 | 1.496 (3) | C11—C9i | 1.401 (3) |
C5—C6 | 1.384 (3) | C11—H11A | 0.9500 |
C5—H5A | 0.9500 | ||
C8—Si1—C7 | 111.07 (16) | C1—C6—H6A | 119.0 |
C8—Si1—C1 | 110.83 (12) | Si1—C7—H7A | 109.5 |
C7—Si1—C1 | 110.34 (13) | Si1—C7—H7B | 109.5 |
C8—Si1—H1 | 108.8 (10) | H7A—C7—H7B | 109.5 |
C7—Si1—H1 | 109.7 (10) | Si1—C7—H7C | 109.5 |
C1—Si1—H1 | 106.0 (10) | H7A—C7—H7C | 109.5 |
C2—C1—C6 | 116.6 (2) | H7B—C7—H7C | 109.5 |
C2—C1—Si1 | 123.04 (18) | Si1—C8—H8A | 109.5 |
C6—C1—Si1 | 120.39 (19) | Si1—C8—H8B | 109.5 |
C3—C2—C1 | 122.0 (2) | H8A—C8—H8B | 109.5 |
C3—C2—H2A | 119.0 | Si1—C8—H8C | 109.5 |
C1—C2—H2A | 119.0 | H8A—C8—H8C | 109.5 |
C2—C3—C4 | 120.7 (2) | H8B—C8—H8C | 109.5 |
C2—C3—H3A | 119.7 | C11i—C9—C10 | 117.8 (2) |
C4—C3—H3A | 119.7 | C11i—C9—C4 | 121.1 (2) |
C5—C4—C3 | 117.8 (2) | C10—C9—C4 | 121.1 (2) |
C5—C4—C9 | 121.3 (2) | C11—C10—C9 | 121.1 (2) |
C3—C4—C9 | 120.9 (2) | C11—C10—H10A | 119.5 |
C6—C5—C4 | 121.0 (2) | C9—C10—H10A | 119.5 |
C6—C5—H5A | 119.5 | C10—C11—C9i | 121.1 (2) |
C4—C5—H5A | 119.5 | C10—C11—H11A | 119.4 |
C5—C6—C1 | 122.0 (2) | C9i—C11—H11A | 119.4 |
C5—C6—H6A | 119.0 | ||
C8—Si1—C1—C2 | 17.6 (3) | C4—C5—C6—C1 | −0.2 (4) |
C7—Si1—C1—C2 | −105.9 (3) | C2—C1—C6—C5 | −0.7 (4) |
C8—Si1—C1—C6 | −163.7 (2) | Si1—C1—C6—C5 | −179.4 (2) |
C7—Si1—C1—C6 | 72.8 (3) | C5—C4—C9—C11i | −154.1 (2) |
C6—C1—C2—C3 | 0.8 (4) | C3—C4—C9—C11i | 26.7 (4) |
Si1—C1—C2—C3 | 179.6 (2) | C5—C4—C9—C10 | 26.2 (4) |
C1—C2—C3—C4 | −0.2 (4) | C3—C4—C9—C10 | −153.1 (2) |
C2—C3—C4—C5 | −0.7 (4) | C11i—C9—C10—C11 | −0.1 (4) |
C2—C3—C4—C9 | 178.6 (2) | C4—C9—C10—C11 | 179.7 (2) |
C3—C4—C5—C6 | 0.9 (4) | C9—C10—C11—C9i | 0.1 (4) |
C9—C4—C5—C6 | −178.4 (2) |
Symmetry code: (i) −x, −y+1, −z+2. |
Cg1 is the centroid of the C1–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8b···Cg1ii | 0.98 | 2.86 | 3.826 (3) | 171 |
C10—H10a···Cg1iii | 0.95 | 2.98 | 3.788 (3) | 143 |
Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) x, −y+3/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C22H26Si2 |
Mr | 346.61 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 15.143 (3), 7.7263 (15), 9.1285 (18) |
β (°) | 107.52 (3) |
V (Å3) | 1018.5 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.18 |
Crystal size (mm) | 0.20 × 0.18 × 0.08 |
Data collection | |
Diffractometer | Rigaku Saturn724+ CCD diffractometer |
Absorption correction | Multi-scan (CrystalClear; Rigaku, 2008) |
Tmin, Tmax | 0.966, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7661, 2218, 1937 |
Rint | 0.043 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.071, 0.133, 1.21 |
No. of reflections | 2218 |
No. of parameters | 115 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.31, −0.22 |
Computer programs: CrystalClear (Rigaku, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPIII (Burnett & Johnson, 1996).
Cg1 is the centroid of the C1–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8b···Cg1i | 0.98 | 2.86 | 3.826 (3) | 171 |
C10—H10a···Cg1ii | 0.95 | 2.98 | 3.788 (3) | 143 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x, −y+3/2, z+1/2. |
Acknowledgements
This work was supported by the National Science Foundation of China (NSFC, Nos. 50673094 and 20774102).
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
p-Terphenyl derivatives have attracted considerable attention due to their extensive applications. Among others, they may be used as laser dyes (Craig et al., 1992), light-emitting materials (Spiliopoulos et al., 2002), liquid crystalline materials (Yam et al., 1993). Although p-terphenyls containing silyl groups have been reported (Feng et al., 2007), their crystal structures have not been given yet.
The title molecules are situated on the crystallographic centres of symmetry (Fig. 1). Two dimethylsilylphenyl-rings are linked to the central benzene ring in its 1,4 (para) positions. The rings are not coplanar; the dihedral angle between the dimethylsilylphenyl-ring and the central benzene ring equals to 26.7 (4)°. There are C-H···π-electron ring interactions in the structure (Tab. 1).
The distance Si1-H1 (1.39 (3)Å) is in a fair accordance to the structures with the R-factor < 0.06 that have been retrieved from the Cambridge Crystallographic Database (version 5.31 from December 2009 with updates up to February 2010). (Allen, 2002). The average retrieved distance is 1.419 (14) Å for 21 observations. [The searched structures contained Si-fragment as it is in the title structure: 2 C atoms in sp3 state, 1 in sp2 state, 1 H. The structures with extensively deviated distances (ROLDIF, ROLDIF01, POZNEX, CODVOH, YOYBOD) have been suppressed.]