(E)-1,2-Bis(diphenyl­methyl­silyl)ethene

The mol­ecule of the title compound, C₂₈H₂₈Si₂, occupies a special position on a centre of symmetry. It adopts an E configuration about the central C=C bond, with an Si—C=C—Si torsion angle of exactly 180°. Weak C—H...π hydrogen bonds and van der Waals interactions determine the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.055
• wR factor = 0.192
• Data-to-parameter ratio = 19.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         43 Perc.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          3

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: KM-4 Software (Kuma, 1991); cell refinement: KM-4 Software; data reduction: KM-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989); software used to prepare material for publication: SHELXL97.

(E)-1,2-Bis(diphenylmethylsilyl)ethene

Crystal data

C28H28Si2	F(000) = 448
Mr = 420.68	Dx = 1.126 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 50 reflections
a = 8.1929 (16) Å	θ = 5–18°
b = 21.189 (3) Å	µ = 0.16 mm^−1
c = 7.192 (2) Å	T = 295 K
β = 96.196 (19)°	Block, colourless
V = 1241.2 (5) Å^3	0.2 × 0.1 × 0.08 mm
Z = 2

Data collection

Kuma KM-4 diffractometer	Rint = 0.066
Radiation source: fine-focus sealed tube	θmax = 27.0°, θmin = 1.9°
Graphite monochromator	h = −10→10
ω–2θ scans	k = −26→0
2856 measured reflections	l = 0→9
2619 independent reflections	2 standard reflections every 100 reflections
1118 reflections with I > 2σ(I)	intensity decay: 1.5%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.192	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0974P)^2 + 0.0739P] where P = (Fo^2 + 2Fc^2)/3
2619 reflections	(Δ/σ)max < 0.002
137 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.26 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Si1	0.62943 (13)	0.06152 (5)	0.23882 (15)	0.0489 (3)
C1	0.5126 (5)	0.00096 (18)	0.0922 (6)	0.0561 (10)
H1	0.4667	−0.0316	0.1558	0.067*
C1A	0.7756 (6)	0.0231 (2)	0.4212 (7)	0.0783 (15)
H1A1	0.7168	−0.0056	0.4931	0.102*
H1A2	0.8281	0.0547	0.5024	0.102*
H1A3	0.8572	0.0003	0.3622	0.102*
C11	0.7464 (4)	0.11097 (17)	0.0823 (5)	0.0476 (9)
C12	0.8716 (6)	0.0852 (2)	−0.0075 (7)	0.0719 (13)
H12	0.8966	0.0427	0.0102	0.086*
C13	0.9611 (6)	0.1205 (3)	−0.1227 (7)	0.0828 (15)
H13	1.0440	0.1019	−0.1825	0.099*
C14	0.9247 (7)	0.1836 (3)	−0.1468 (7)	0.0880 (16)
H14	0.9849	0.2081	−0.2221	0.106*
C15	0.8021 (7)	0.2102 (2)	−0.0619 (7)	0.0779 (14)
H15	0.7774	0.2528	−0.0802	0.093*
C16	0.7144 (5)	0.17448 (19)	0.0511 (6)	0.0591 (11)
H16	0.6306	0.1935	0.1087	0.071*
C21	0.4805 (4)	0.11253 (17)	0.3491 (5)	0.0466 (9)
C22	0.3250 (5)	0.1242 (2)	0.2601 (6)	0.0649 (12)
H22	0.2942	0.1051	0.1453	0.078*
C23	0.2145 (6)	0.1630 (2)	0.3350 (7)	0.0732 (13)
H23	0.1108	0.1694	0.2716	0.088*
C24	0.2573 (6)	0.1921 (2)	0.5027 (7)	0.0757 (14)
H24	0.1838	0.2189	0.5530	0.091*
C25	0.4103 (6)	0.1813 (2)	0.5965 (7)	0.0764 (13)
H25	0.4398	0.2008	0.7110	0.092*
C26	0.5194 (5)	0.1419 (2)	0.5221 (6)	0.0633 (12)
H26	0.6216	0.1347	0.5883	0.076*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0507 (6)	0.0440 (5)	0.0499 (6)	0.0002 (5)	−0.0043 (4)	−0.0026 (5)
C1	0.064 (2)	0.043 (2)	0.060 (2)	−0.0068 (17)	−0.001 (2)	−0.002 (2)
C1A	0.085 (3)	0.068 (3)	0.076 (3)	0.012 (2)	−0.019 (3)	0.002 (2)
C11	0.0442 (19)	0.048 (2)	0.049 (2)	−0.0025 (16)	−0.0033 (16)	−0.0088 (17)
C12	0.062 (3)	0.062 (3)	0.093 (4)	0.000 (2)	0.013 (3)	−0.013 (3)
C13	0.062 (3)	0.106 (4)	0.083 (4)	−0.011 (3)	0.020 (3)	−0.024 (3)
C14	0.097 (4)	0.102 (4)	0.065 (3)	−0.040 (3)	0.008 (3)	−0.008 (3)
C15	0.105 (4)	0.065 (3)	0.064 (3)	−0.013 (3)	0.012 (3)	0.006 (2)
C16	0.069 (3)	0.050 (2)	0.058 (3)	−0.002 (2)	0.005 (2)	−0.006 (2)
C21	0.049 (2)	0.043 (2)	0.047 (2)	−0.0053 (16)	0.0037 (17)	−0.0003 (17)
C22	0.061 (3)	0.069 (3)	0.063 (3)	0.007 (2)	0.001 (2)	−0.008 (2)
C23	0.061 (3)	0.080 (3)	0.079 (4)	0.010 (2)	0.006 (2)	−0.005 (3)
C24	0.076 (3)	0.076 (3)	0.080 (4)	0.017 (3)	0.031 (3)	−0.006 (3)
C25	0.090 (4)	0.082 (3)	0.059 (3)	0.004 (3)	0.012 (3)	−0.020 (3)
C26	0.065 (3)	0.065 (3)	0.059 (3)	0.000 (2)	0.001 (2)	−0.009 (2)

Geometric parameters (Å, º)

Si1—C1	1.860 (4)	C14—H14	0.9300
Si1—C1A	1.866 (4)	C15—C16	1.370 (6)
Si1—C21	1.870 (4)	C15—H15	0.9300
Si1—C11	1.875 (4)	C16—H16	0.9300
C1—C1^i	1.320 (8)	C21—C22	1.385 (5)
C1—H1	0.9300	C21—C26	1.397 (5)
C1A—H1A1	0.9600	C22—C23	1.375 (6)
C1A—H1A2	0.9600	C22—H22	0.9300
C1A—H1A3	0.9600	C23—C24	1.366 (6)
C11—C12	1.382 (6)	C23—H23	0.9300
C11—C16	1.385 (5)	C24—C25	1.376 (6)
C12—C13	1.382 (7)	C24—H24	0.9300
C12—H12	0.9300	C25—C26	1.373 (6)
C13—C14	1.377 (7)	C25—H25	0.9300
C13—H13	0.9300	C26—H26	0.9300
C14—C15	1.354 (7)
C1—Si1—C1A	110.5 (2)	C13—C14—H14	119.7
C1—Si1—C21	108.66 (18)	C14—C15—C16	119.9 (5)
C1A—Si1—C21	110.7 (2)	C14—C15—H15	120.0
C1—Si1—C11	108.08 (18)	C16—C15—H15	120.0
C1A—Si1—C11	109.6 (2)	C15—C16—C11	122.1 (4)
C21—Si1—C11	109.33 (16)	C15—C16—H16	118.9
C1^i—C1—Si1	127.3 (4)	C11—C16—H16	119.0
C1^i—C1—H1	116.4	C22—C21—C26	116.3 (4)
Si1—C1—H1	116.4	C22—C21—Si1	121.1 (3)
Si1—C1A—H1A1	109.5	C26—C21—Si1	122.6 (3)
Si1—C1A—H1A2	109.5	C23—C22—C21	122.5 (4)
H1A1—C1A—H1A2	109.5	C23—C22—H22	118.8
Si1—C1A—H1A3	109.5	C21—C22—H22	118.8
H1A1—C1A—H1A3	109.5	C24—C23—C22	119.9 (4)
H1A2—C1A—H1A3	109.5	C24—C23—H23	120.1
C12—C11—C16	116.4 (4)	C22—C23—H23	120.0
C12—C11—Si1	120.9 (3)	C23—C24—C25	119.4 (4)
C16—C11—Si1	122.7 (3)	C23—C24—H24	120.3
C11—C12—C13	122.4 (5)	C25—C24—H24	120.3
C11—C12—H12	118.8	C26—C25—C24	120.4 (4)
C13—C12—H12	118.8	C26—C25—H25	119.8
C14—C13—C12	118.6 (5)	C24—C25—H25	119.8
C14—C13—H13	120.7	C25—C26—C21	121.5 (4)
C12—C13—H13	120.7	C25—C26—H26	119.3
C15—C14—C13	120.6 (5)	C21—C26—H26	119.3
C15—C14—H14	119.7
C1A—Si1—C1—C1^i	−132.1 (5)	Si1—C11—C16—C15	179.2 (3)
C21—Si1—C1—C1^i	106.3 (6)	C1—Si1—C21—C22	−30.9 (4)
C11—Si1—C1—C1^i	−12.2 (6)	C1A—Si1—C21—C22	−152.3 (4)
C1—Si1—C11—C12	−65.8 (4)	C11—Si1—C21—C22	86.9 (4)
C1A—Si1—C11—C12	54.6 (4)	C1—Si1—C21—C26	150.5 (3)
C21—Si1—C11—C12	176.1 (3)	C1A—Si1—C21—C26	29.0 (4)
C1—Si1—C11—C16	114.7 (3)	C11—Si1—C21—C26	−91.8 (3)
C1A—Si1—C11—C16	−124.9 (3)	C26—C21—C22—C23	0.7 (6)
C21—Si1—C11—C16	−3.4 (4)	Si1—C21—C22—C23	−178.0 (3)
C16—C11—C12—C13	0.0 (6)	C21—C22—C23—C24	0.6 (7)
Si1—C11—C12—C13	−179.5 (4)	C22—C23—C24—C25	−1.1 (7)
C11—C12—C13—C14	0.7 (7)	C23—C24—C25—C26	0.3 (8)
C12—C13—C14—C15	−1.1 (8)	C24—C25—C26—C21	1.0 (7)
C13—C14—C15—C16	0.8 (8)	C22—C21—C26—C25	−1.5 (6)
C14—C15—C16—C11	−0.1 (7)	Si1—C21—C26—C25	177.2 (4)
C12—C11—C16—C15	−0.3 (6)

Symmetry code: (i) −x+1, −y, −z.