(E)-1,2-Bis{4-[dimeth­yl(vin­yl)silyl]­phenyl}­ethene

Mariusz Majchrzak; Bogdan Marciniec; Maciej Kubicki

doi:10.1107/S1600536807062976

. 2007 Dec 6;64(Pt 1):o93. doi: 10.1107/S1600536807062976

(E)-1,2-Bis{4-[dimethyl(vinyl)silyl]phenyl}ethene

Mariusz Majchrzak ^a, Bogdan Marciniec ^a, Maciej Kubicki ^a,^*

PMCID: PMC2915048 PMID: 21200970

Abstract

The molecule of the title compound, C₃₂H₃₄Si₂, is situated about a centre of symmetry. The whole diphenylethene fragment is planar and the C_ar—Si—C₃ group is rotated by ca 30° with respect to the plane of the benzene ring. The crystal structure is stabilized by some C—H⋯π contacts as well as van der Waals interactions.

Related literature

For related literature, see: JanBen & Krause (2005 ▶); Maciejewski et al. (2003 ▶); Majchrzak et al. (2005 ▶, 2007 ▶).

Experimental

Crystal data

C₂₂H₂₈Si₂
M _r = 348.62
Monoclinic,
a = 21.762 (2) Å
b = 6.2880 (9) Å
c = 19.159 (2) Å
β = 124.05 (2)°
V = 2172.2 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.16 mm⁻¹
T = 295 (2) K
0.3 × 0.2 × 0.15 mm

Data collection

Kuma KM4CCD four-circle diffractometer
Absorption correction: none
5962 measured reflections
2116 independent reflections
1441 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.120
S = 0.99
2116 reflections
165 parameters
All H-atom parameters refined
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: XP (Siemens, 1989 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807062976/tk2222sup1.cif

e-64-00o93-sup1.cif^{(13.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807062976/tk2222Isup2.hkl

e-64-00o93-Isup2.hkl^{(102KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12A⋯Cg1ⁱ	0.88 (3)	2.99 (3)	3.872 (3)	174 (2)
C13—H13C⋯Cg1ⁱⁱ	0.97 (3)	3.03 (3)	3.912 (4)	152 (2)

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 is the centroid of the C1–C6 ring.

supplementary crystallographic information

Comment

The synthesis of {(E)-1,2-bis(4-(dimethyl(vinyl)silyl)phenyl)}ethene, (I), consisted of two steps. During first step, the well know metathesis reaction of 4-bromostyrene was applied to obtain {(E)-1,2-bis(4-bromophenyl)}ethene which was used as a substrate for the second step, the typical reaction between an aryl-halide derivative of an olefin, a Grignard reagent generated in situ and vinylchlorosilane. This kind of vinylsilane-stilbene can be used as a very efficient monomer for the synthesis of arylene-silylene-vinylene polymers, polycarbosilanes or co-polymers with suitable aromatic olefin via silylative coupling polycondensation (SCP) or polyhydrosilylation reactions (Majchrzak et al., 2005, 2007; Maciejewski et al., 2003).

The molecule of (I) is centrosymmetric with the mid-point of the central C41?C41A bond lying on a centre of symmetry (Fig. 1). The phenyl rings (planar within 0.0046 (14) Å) are, from symmetry, co-planar. As the C41 and Si1 atoms are almost co-planar with these rings (deviation from the least-squares plane = 0.009 (3)Å and 0.054 (3) Å, respectively), the whole diphenylethene fragment is planar. The C(ar)—Si—C₃group is rotated by ca 30° with respect to to the plane of the phenyl ring, as can be seen from the values of C2—C1—Si—C(X) torsion angles: 28.5 (2)° for X = 13, -92.5 (2)° for X = 12, and 148.0 (2)° for X = 11. The crystal structure is stabilized by some relatively directional C—H···π contacts as well as van der Waals interactions.

Experimental

First Step: A solution of 4-bromostyrene (6.095 g, 33.30 mmol) in THF (35 ml) was placed in a 50 ml glass two-neck mini reactor which was fitted with a condenser connected with an inert gas line. The Hoveyda–Grubbs catalyst 1^st generation (10 mg, 0.017 mmol) was added and the reaction mixture was heated at 316–318 K and left for 5 h. The crude product was precipitated partially from solution. After the reaction was completed, the mixture was cooled to room temperature and the excess of organic solvent was evaporated under high vacuum. The mix of yellowish crystals was recovered by filtration and washed with cold hexane (3 x 10 ml). The residue was recrystallized from ethanol to provide 5.46 g (16.15 mmol, yield 97%) (E)-4,4'-dibromostilbene as a colorless solid. ¹H NMR (CDCl₃, δ (p.p.m.)): 7.06 (s, 2H, –CH=CH-), 7.42 (d, J_HH = 8.80 Hz, 4H, o-C₆H₄-Br), 7.52 (d, J_HH = 8.75 Hz, 4H, m-C₆H₄-Br). ¹³C NMR (CDCl₃, δ (p.p.m.)): 122.6 (Br—C_i<), 127.3 (-CH=CH–), 129.8 (Br-m-C₆H₄–), 132.6 (Br-o-C₆H₄–), 137.1 (>C_i-CH=). MS—EI (M/z (%)) 338 (100) [M⁺], 258 (17), 178 (85), 152 (8), 89 (6). HRMS (m/z) calcd. for C₁₄H₁₀Br₂: 335.91493, found: 335.91374. m. p. 481–489 K, Lit. (JanBen & Krause, 2005): 483 K.

Second Step: A solution of (E)-4,4'-dibromostilbene (3 g, 8.87 mmol) in THF (15 ml) was added dropwise to a suspension of Mg (0.518 g, 21.30 mmol, whose surface was activated by use of 1,2-dibromomethane (50 µL) and vinyldimethylchlorosilane (2.35 g, 19.51 mmol) in slighly warm THF (15 ml). After the addition was completed, the reaction mixture was heated at 318 K for 4 h. The mixture was cooled to room temperature, water (2 ml) was added, and the whole was filtered. The organic phase was left overnight with magnesium sulfate. The solvent was then evaporated and the residual solid was washed by cold hexane (2 x 15 ml). The isolated compound was recrystallized from ethanol to yield 2.1 g of (I) (6.02 mmol, yield 68%) as a colourless solid. ¹H NMR (CDCl₃, δ(p.p.m.)): 0.29 (s, 12H, –CH₃), 5.82 (dd, 2H, J_HH = 3.8, 20.1 Hz, –CH=CH₂), 6.11 (dd, 2H, J_HH = 3.8, 15.1 Hz, –CH=CH₂), 6.34 (dd, 2H, J_HH = 14.6, 20.1 Hz, –CH=CH₂), 7.11 (s, 2H, –CH=CH-), 7.48 (d, 4H, o-C₆H₄-Si), 7.54 (d, 4H, m-C₆H₄-Si). ¹³C NMR (CDCl₃, δ(p.p.m.)): -2.8, 127.3, 129.8, 135.9, 136.3, 137.8, 139.3, 140.1. ²⁹Si NMR (CDCl₃, δ(p.p.m.)): -10.60. HRMS (m/z) calcd. for C₂₂H₂₈Si₂: 348.17295, found 348.17284. Analysis: found C 75.72, H 8.09%. C₂₂H₂₈Si₂ requires: C 75.79, H 8.1%.