2,2,6,6-Tetra-kis(biphenyl-2-yl)-4,4,8,8-tetra-methyl-cyclo-tetra-siloxane.

The title compound, [-Si(C(12)H(9))(2)OSi(CH(3))(2)O-](2), was obtained unintentionally as the product of an attempted crystallization of caesium bis-(biphenyl-2,2'-di-yl)fluoro-silicate from dimethyl-formamide. In the crystal, the mol-ecule is located on an inversion center and the siloxane ring adopts a twist-chair conformation with the two dimethyl-substituted Si atoms lying 0.7081 (5) Å out of the plane defined by the two bis-(biphenyl-2-yl)-substituted Si atoms and the four O atoms. In each Si(C(12)H(9))(2) unit, the orientation of one terminal phenyl ring relative to the phenyl-ene ring of the other biphenyl moiety suggests a parallel displaced π-π stacking inter-action [centroid distance = 4.2377 (11) Å and dihedral angle = 15.40 (9)°].

Related literature

For general background to stable compounds of penta­valent, anionic silicon bearing five organic substituents, see: Couzijn et al. (2004 ▶, 2006 ▶, 2009 ▶); Deerenberg et al. (2002 ▶); de Keijzer et al. (1997 ▶). For related structures, see: Malinovskii et al. (2007 ▶); Steinfink et al. (1955 ▶); Hensen et al. (1997 ▶). For puckering analysis,, see: Evans & Boeyens (1989 ▶). Bis(biphenyl-2,2′-di­yl)silane was synthesized using a slight modification of a literature procedure (Gilman & Gorsich, 1958 ▶).

Experimental

Crystal data

C52H48O4Si4

M = 849.26

Orthorhombic,

a = 17.3418 (2) Å

b = 14.6488 (2) Å

c = 17.9584 (2) Å

V = 4562.09 (10) Å3

Z = 4

Mo Kα radiation

μ = 0.18 mm−1

T = 110 K

0.30 × 0.12 × 0.03 mm

Data collection

Nonius KappaCCD diffractometer

Absorption correction: none

68467 measured reflections

4317 independent reflections

3247 reflections with I > 2σ(I)

R int = 0.081

Refinement

R[F 2 > 2σ(F 2)] = 0.036

wR(F 2) = 0.097

S = 1.07

4317 reflections

273 parameters

H-atom parameters constrained

Δρmax = 0.26 e Å−3

Δρmin = −0.33 e Å−3

Data collection: COLLECT (Nonius, 1999 ▶); cell refinement: HKL-2000 (Otwinowski & Minor, 1997 ▶); data reduction: HKL-2000 and SORTAV (Blessing, 1997 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: manual editing of SHELXL output.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809031961/vm2002sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809031961/vm2002Isup2.hkl

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

C52H48O4Si4	F(000) = 1792
Mr = 849.26	Dx = 1.236 Mg m−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 88729 reflections
a = 17.3418 (2) Å	θ = 1.0–25.7°
b = 14.6488 (2) Å	µ = 0.18 mm−1
c = 17.9584 (2) Å	T = 110 K
V = 4562.09 (10) Å3	Needle, colourless
Z = 4	0.30 × 0.12 × 0.03 mm

Nonius KappaCCD diffractometer	3247 reflections with I > 2σ(I)
Radiation source: rotating anode	Rint = 0.081
graphite	θmax = 25.7°, θmin = 2.1°
φ and ω scans	h = −21→21
68467 measured reflections	k = −17→17
4317 independent reflections	l = −21→21

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)] = 0.036	Hydrogen site location: difference Fourier map
wR(F2) = 0.097	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0428P)2 + 1.7858P] where P = (Fo2 + 2Fc2)/3
4317 reflections	(Δ/σ)max = 0.001
273 parameters	Δρmax = 0.26 e Å−3
0 restraints	Δρmin = −0.33 e Å−3

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 > 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	0.42728 (3)	0.37257 (3)	0.49618 (3)	0.02364 (14)
Si2	0.41400 (3)	0.57131 (3)	0.44096 (3)	0.02422 (14)
O1	0.42038 (7)	0.45998 (8)	0.44053 (6)	0.0257 (3)
O2	0.49862 (7)	0.38739 (8)	0.55394 (6)	0.0272 (3)
C1	0.35711 (12)	0.60943 (14)	0.52232 (11)	0.0382 (5)
H1A	0.3064	0.5798	0.5215	0.057*
H1B	0.3505	0.6758	0.5203	0.057*
H1C	0.3843	0.5928	0.5682	0.057*
C2	0.37276 (12)	0.60687 (14)	0.35079 (11)	0.0367 (5)
H2A	0.4062	0.5858	0.3103	0.055*
H2B	0.3689	0.6736	0.3492	0.055*
H2C	0.3213	0.5801	0.3450	0.055*
C11	0.45192 (10)	0.27253 (12)	0.43560 (9)	0.0243 (4)
C21	0.46918 (11)	0.28754 (13)	0.36038 (10)	0.0298 (4)
H21	0.4646	0.3475	0.3408	0.036*
C31	0.49264 (11)	0.21768 (13)	0.31368 (10)	0.0332 (5)
H31	0.5034	0.2298	0.2628	0.040*
C41	0.50025 (12)	0.13027 (13)	0.34161 (11)	0.0329 (5)
H41	0.5165	0.0820	0.3100	0.039*
C51	0.48408 (11)	0.11334 (13)	0.41570 (10)	0.0305 (4)
H51	0.4901	0.0533	0.4347	0.037*
C61	0.45917 (10)	0.18265 (12)	0.46293 (10)	0.0240 (4)
C71	0.43948 (10)	0.15854 (11)	0.54194 (10)	0.0252 (4)
C81	0.36294 (11)	0.14336 (12)	0.56199 (10)	0.0307 (4)
H81	0.3233	0.1526	0.5263	0.037*
C91	0.34381 (12)	0.11508 (13)	0.63306 (11)	0.0347 (5)
H91	0.2914	0.1045	0.6457	0.042*
C101	0.40081 (13)	0.10219 (13)	0.68579 (11)	0.0358 (5)
H101	0.3877	0.0827	0.7346	0.043*
C111	0.47717 (12)	0.11785 (13)	0.66701 (10)	0.0342 (5)
H111	0.5165	0.1096	0.7032	0.041*
C121	0.49649 (11)	0.14550 (12)	0.59550 (10)	0.0300 (4)
H121	0.5490	0.1556	0.5830	0.036*
C12	0.33957 (11)	0.36475 (12)	0.55627 (10)	0.0264 (4)
C22	0.35201 (12)	0.35934 (12)	0.63354 (10)	0.0319 (5)
H22	0.4034	0.3554	0.6517	0.038*
C32	0.29145 (13)	0.35950 (13)	0.68412 (11)	0.0386 (5)
H32	0.3015	0.3561	0.7360	0.046*
C42	0.21658 (13)	0.36468 (15)	0.65844 (12)	0.0433 (5)
H42	0.1749	0.3641	0.6927	0.052*
C52	0.20213 (12)	0.37074 (14)	0.58287 (11)	0.0388 (5)
H52	0.1504	0.3745	0.5658	0.047*
C62	0.26242 (11)	0.37139 (12)	0.53110 (10)	0.0298 (4)
C72	0.24184 (11)	0.38291 (13)	0.45090 (11)	0.0299 (4)
C82	0.26624 (11)	0.32206 (13)	0.39587 (10)	0.0328 (5)
H82	0.2966	0.2707	0.4094	0.039*
C92	0.24684 (12)	0.33543 (15)	0.32168 (11)	0.0392 (5)
H92	0.2643	0.2936	0.2850	0.047*
C102	0.20206 (12)	0.40966 (15)	0.30091 (11)	0.0399 (5)
H102	0.1891	0.4190	0.2501	0.048*
C112	0.17661 (12)	0.46966 (15)	0.35464 (11)	0.0392 (5)
H112	0.1457	0.5205	0.3409	0.047*
C122	0.19584 (11)	0.45615 (14)	0.42866 (11)	0.0346 (5)
H122	0.1773	0.4977	0.4651	0.042*

	U11	U22	U33	U12	U13	U23
Si1	0.0279 (3)	0.0196 (3)	0.0235 (3)	−0.0010 (2)	0.0023 (2)	−0.0001 (2)
Si2	0.0271 (3)	0.0214 (3)	0.0241 (3)	0.0024 (2)	0.0005 (2)	0.0006 (2)
O1	0.0306 (7)	0.0207 (6)	0.0258 (6)	−0.0004 (5)	0.0028 (5)	0.0004 (5)
O2	0.0308 (7)	0.0240 (6)	0.0266 (7)	−0.0015 (5)	0.0002 (5)	0.0014 (5)
C1	0.0389 (12)	0.0349 (11)	0.0409 (12)	0.0038 (9)	0.0085 (9)	−0.0055 (9)
C2	0.0380 (12)	0.0349 (11)	0.0370 (11)	−0.0011 (9)	−0.0074 (9)	0.0067 (9)
C11	0.0237 (9)	0.0242 (9)	0.0251 (9)	−0.0016 (8)	−0.0005 (7)	−0.0011 (7)
C21	0.0359 (11)	0.0253 (10)	0.0282 (10)	0.0007 (8)	0.0037 (8)	0.0018 (8)
C31	0.0392 (12)	0.0334 (11)	0.0270 (10)	0.0006 (9)	0.0067 (8)	−0.0029 (8)
C41	0.0392 (12)	0.0278 (10)	0.0317 (10)	0.0028 (9)	0.0079 (9)	−0.0063 (8)
C51	0.0336 (11)	0.0220 (9)	0.0359 (11)	0.0030 (8)	0.0039 (9)	−0.0004 (8)
C61	0.0214 (9)	0.0242 (9)	0.0263 (9)	−0.0010 (7)	0.0000 (7)	0.0001 (7)
C71	0.0314 (10)	0.0155 (8)	0.0286 (10)	0.0006 (7)	0.0010 (8)	−0.0017 (7)
C81	0.0306 (11)	0.0295 (10)	0.0321 (10)	−0.0019 (8)	−0.0002 (8)	−0.0003 (8)
C91	0.0358 (12)	0.0348 (11)	0.0335 (11)	−0.0058 (9)	0.0071 (9)	0.0017 (9)
C101	0.0553 (14)	0.0257 (10)	0.0264 (10)	0.0006 (9)	0.0074 (9)	0.0003 (8)
C111	0.0422 (12)	0.0309 (11)	0.0295 (11)	0.0062 (9)	−0.0052 (9)	−0.0010 (8)
C121	0.0299 (10)	0.0267 (10)	0.0335 (11)	0.0039 (8)	0.0000 (8)	−0.0023 (8)
C12	0.0332 (10)	0.0194 (9)	0.0267 (9)	−0.0025 (8)	0.0051 (8)	−0.0018 (7)
C22	0.0390 (12)	0.0257 (10)	0.0309 (10)	−0.0029 (9)	0.0045 (9)	0.0001 (8)
C32	0.0524 (14)	0.0356 (12)	0.0278 (10)	−0.0059 (10)	0.0092 (10)	−0.0010 (9)
C42	0.0449 (14)	0.0489 (13)	0.0361 (12)	−0.0058 (11)	0.0183 (10)	−0.0042 (10)
C52	0.0325 (12)	0.0449 (13)	0.0390 (12)	−0.0043 (9)	0.0087 (9)	−0.0041 (10)
C62	0.0349 (11)	0.0239 (10)	0.0304 (10)	−0.0051 (8)	0.0064 (8)	−0.0041 (8)
C72	0.0239 (10)	0.0297 (10)	0.0360 (10)	−0.0065 (8)	0.0053 (8)	−0.0033 (8)
C82	0.0298 (11)	0.0332 (11)	0.0354 (11)	−0.0032 (9)	0.0027 (8)	−0.0048 (9)
C92	0.0349 (12)	0.0465 (13)	0.0361 (11)	−0.0050 (10)	0.0043 (9)	−0.0096 (10)
C102	0.0331 (12)	0.0549 (14)	0.0318 (11)	−0.0042 (10)	0.0011 (9)	0.0018 (10)
C112	0.0297 (11)	0.0446 (13)	0.0432 (12)	0.0014 (9)	0.0020 (9)	0.0052 (10)
C122	0.0282 (11)	0.0372 (11)	0.0386 (11)	−0.0029 (9)	0.0065 (9)	−0.0047 (9)

Si1—O1	1.6287 (12)	C91—C101	1.382 (3)
Si1—O2	1.6290 (13)	C91—H91	0.9500
Si1—C12	1.8684 (19)	C101—C111	1.386 (3)
Si1—C11	1.8746 (17)	C101—H101	0.9500
Si2—O2i	1.6342 (13)	C111—C121	1.387 (3)
Si2—O1	1.6347 (12)	C111—H111	0.9500
Si2—C2	1.8452 (19)	C121—H121	0.9500
Si2—C1	1.8494 (19)	C12—C22	1.407 (3)
O2—Si2i	1.6342 (13)	C12—C62	1.415 (3)
C1—H1A	0.9800	C22—C32	1.388 (3)
C1—H1B	0.9800	C22—H22	0.9500
C1—H1C	0.9800	C32—C42	1.380 (3)
C2—H2A	0.9800	C32—H32	0.9500
C2—H2B	0.9800	C42—C52	1.383 (3)
C2—H2C	0.9800	C42—H42	0.9500
C11—C21	1.401 (2)	C52—C62	1.399 (3)
C11—C61	1.411 (2)	C52—H52	0.9500
C21—C31	1.384 (3)	C62—C72	1.493 (3)
C21—H21	0.9500	C72—C122	1.395 (3)
C31—C41	1.381 (3)	C72—C82	1.396 (3)
C31—H31	0.9500	C82—C92	1.388 (3)
C41—C51	1.382 (3)	C82—H82	0.9500
C41—H41	0.9500	C92—C102	1.387 (3)
C51—C61	1.392 (2)	C92—H92	0.9500
C51—H51	0.9500	C102—C112	1.378 (3)
C61—C71	1.501 (2)	C102—H102	0.9500
C71—C121	1.393 (3)	C112—C122	1.385 (3)
C71—C81	1.393 (3)	C112—H112	0.9500
C81—C91	1.382 (3)	C122—H122	0.9500
C81—H81	0.9500
O1—Si1—O2	109.98 (7)	C71—C81—H81	119.5
O1—Si1—C12	110.05 (7)	C101—C91—C81	120.13 (19)
O2—Si1—C12	105.00 (8)	C101—C91—H91	119.9
O1—Si1—C11	105.97 (7)	C81—C91—H91	119.9
O2—Si1—C11	107.49 (7)	C91—C101—C111	119.62 (18)
C12—Si1—C11	118.22 (8)	C91—C101—H101	120.2
O2i—Si2—O1	107.88 (7)	C111—C101—H101	120.2
O2i—Si2—C2	107.71 (8)	C101—C111—C121	120.29 (18)
O1—Si2—C2	107.68 (8)	C101—C111—H111	119.9
O2i—Si2—C1	109.78 (8)	C121—C111—H111	119.9
O1—Si2—C1	109.94 (8)	C111—C121—C71	120.53 (18)
C2—Si2—C1	113.66 (10)	C111—C121—H121	119.7
Si1—O1—Si2	141.85 (8)	C71—C121—H121	119.7
Si1—O2—Si2i	142.12 (8)	C22—C12—C62	117.63 (17)
Si2—C1—H1A	109.5	C22—C12—Si1	116.64 (14)
Si2—C1—H1B	109.5	C62—C12—Si1	125.51 (14)
H1A—C1—H1B	109.5	C32—C22—C12	121.96 (19)
Si2—C1—H1C	109.5	C32—C22—H22	119.0
H1A—C1—H1C	109.5	C12—C22—H22	119.0
H1B—C1—H1C	109.5	C42—C32—C22	119.55 (19)
Si2—C2—H2A	109.5	C42—C32—H32	120.2
Si2—C2—H2B	109.5	C22—C32—H32	120.2
H2A—C2—H2B	109.5	C32—C42—C52	120.13 (19)
Si2—C2—H2C	109.5	C32—C42—H42	119.9
H2A—C2—H2C	109.5	C52—C42—H42	119.9
H2B—C2—H2C	109.5	C42—C52—C62	121.1 (2)
C21—C11—C61	117.57 (16)	C42—C52—H52	119.4
C21—C11—Si1	119.05 (13)	C62—C52—H52	119.4
C61—C11—Si1	123.23 (13)	C52—C62—C12	119.58 (18)
C31—C21—C11	122.07 (17)	C52—C62—C72	117.58 (18)
C31—C21—H21	119.0	C12—C62—C72	122.79 (16)
C11—C21—H21	119.0	C122—C72—C82	117.48 (18)
C41—C31—C21	119.56 (17)	C122—C72—C62	119.97 (17)
C41—C31—H31	120.2	C82—C72—C62	122.54 (17)
C21—C31—H31	120.2	C92—C82—C72	121.05 (19)
C31—C41—C51	119.77 (17)	C92—C82—H82	119.5
C31—C41—H41	120.1	C72—C82—H82	119.5
C51—C41—H41	120.1	C102—C92—C82	120.29 (19)
C41—C51—C61	121.25 (17)	C102—C92—H92	119.9
C41—C51—H51	119.4	C82—C92—H92	119.9
C61—C51—H51	119.4	C112—C102—C92	119.40 (19)
C51—C61—C11	119.77 (16)	C112—C102—H102	120.3
C51—C61—C71	118.35 (16)	C92—C102—H102	120.3
C11—C61—C71	121.87 (15)	C102—C112—C122	120.3 (2)
C121—C71—C81	118.42 (17)	C102—C112—H112	119.9
C121—C71—C61	121.58 (16)	C122—C112—H112	119.9
C81—C71—C61	119.90 (16)	C112—C122—C72	121.49 (19)
C91—C81—C71	121.01 (18)	C112—C122—H122	119.3
C91—C81—H81	119.5	C72—C122—H122	119.3
O1—Si2—O2i—Si1i	−74.36 (14)	C81—C91—C101—C111	0.1 (3)
O2—Si1—O1—Si2	−52.51 (15)	C91—C101—C111—C121	−0.6 (3)
C12—Si1—O1—Si2	62.69 (15)	C101—C111—C121—C71	0.5 (3)
C11—Si1—O1—Si2	−168.40 (12)	C81—C71—C121—C111	0.1 (3)
O2i—Si2—O1—Si1	84.84 (14)	C61—C71—C121—C111	−176.07 (16)
C2—Si2—O1—Si1	−159.17 (13)	O1—Si1—C12—C22	−127.17 (14)
C1—Si2—O1—Si1	−34.85 (16)	O2—Si1—C12—C22	−8.85 (15)
O1—Si1—O2—Si2i	−37.42 (15)	C11—Si1—C12—C22	110.94 (14)
C12—Si1—O2—Si2i	−155.78 (13)	O1—Si1—C12—C62	47.32 (17)
C11—Si1—O2—Si2i	77.52 (14)	O2—Si1—C12—C62	165.63 (15)
O1—Si1—C11—C21	7.60 (16)	C11—Si1—C12—C62	−74.57 (17)
O2—Si1—C11—C21	−109.97 (15)	C62—C12—C22—C32	0.6 (3)
C12—Si1—C11—C21	131.54 (15)	Si1—C12—C22—C32	175.55 (14)
O1—Si1—C11—C61	−176.83 (14)	C12—C22—C32—C42	0.3 (3)
O2—Si1—C11—C61	65.60 (16)	C22—C32—C42—C52	−0.8 (3)
C12—Si1—C11—C61	−52.89 (18)	C32—C42—C52—C62	0.3 (3)
C61—C11—C21—C31	−0.1 (3)	C42—C52—C62—C12	0.7 (3)
Si1—C11—C21—C31	175.77 (15)	C42—C52—C62—C72	−176.95 (19)
C11—C21—C31—C41	−0.7 (3)	C22—C12—C62—C52	−1.1 (3)
C21—C31—C41—C51	0.3 (3)	Si1—C12—C62—C52	−175.54 (14)
C31—C41—C51—C61	0.8 (3)	C22—C12—C62—C72	176.41 (17)
C41—C51—C61—C11	−1.6 (3)	Si1—C12—C62—C72	2.0 (3)
C41—C51—C61—C71	177.46 (18)	C52—C62—C72—C122	52.9 (2)
C21—C11—C61—C51	1.1 (3)	C12—C62—C72—C122	−124.6 (2)
Si1—C11—C61—C51	−174.49 (14)	C52—C62—C72—C82	−126.4 (2)
C21—C11—C61—C71	−177.85 (16)	C12—C62—C72—C82	56.1 (3)
Si1—C11—C61—C71	6.5 (2)	C122—C72—C82—C92	1.5 (3)
C51—C61—C71—C121	78.6 (2)	C62—C72—C82—C92	−179.20 (18)
C11—C61—C71—C121	−102.4 (2)	C72—C82—C92—C102	−0.5 (3)
C51—C61—C71—C81	−97.5 (2)	C82—C92—C102—C112	−0.4 (3)
C11—C61—C71—C81	81.5 (2)	C92—C102—C112—C122	0.3 (3)
C121—C71—C81—C91	−0.7 (3)	C102—C112—C122—C72	0.8 (3)
C61—C71—C81—C91	175.58 (17)	C82—C72—C122—C112	−1.7 (3)
C71—C81—C91—C101	0.6 (3)	C62—C72—C122—C112	179.02 (17)

Si1—O1	1.6287 (12)
Si1—O2	1.6290 (13)
Si1—C12	1.8684 (19)
Si1—C11	1.8746 (17)
Si2—O2i	1.6342 (13)
Si2—O1	1.6347 (12)
Si2—C2	1.8452 (19)
Si2—C1	1.8494 (19)

O1—Si1—O2	109.98 (7)
O2i—Si2—O1	107.88 (7)
Si1—O1—Si2	141.85 (8)
Si1—O2—Si2i	142.12 (8)

O1—Si2—O2i—Si1i	−74.36 (14)
O2—Si1—O1—Si2	−52.51 (15)
O2i—Si2—O1—Si1	84.84 (14)
O1—Si1—O2—Si2i	−37.42 (15)
C11—C61—C71—C81	81.5 (2)
C12—C62—C72—C82	56.1 (3)

Symmetry code: (i) .