1,1-Bis(tert-butyl­amido)-3,3,5,5-tetra­phenyl­cyclo­trisiloxane

The title compound, C₃₂H₄₀N₂O₃Si₃ or (Ph₂SiO)₂OSi(NH-^tBu)₂, was synthesized by the in situ reaction of [Ph₂Si(OH)]₂O with two equivalents of ⁿBuLi, followed by the addition of Cl₂Si(NH-^tBu)₂. The addition of tert-butyl­amide substituents to one of the Si centres causes a slight distortion of the planar cyclo­trisiloxane ring.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.045
• wR factor = 0.117
• Data-to-parameter ratio = 15.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.04 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C25
PLAT318_ALERT_2_C Check Hybridisation of  N1     in Main Residue .          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H1A    ...          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N2     -   H2A    ...          ?

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

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

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Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997); data reduction: DENZO; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

1,1-Bis(tert-butylamido)-3,3,5,5-tetraphenylcyclotrisiloxane

Crystal data

C32H40N2O3Si3	F(000) = 1248
Mr = 584.93	Dx = 1.199 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 10563 reflections
a = 10.246 (2) Å	θ = 3.4–27.5°
b = 15.759 (3) Å	µ = 0.18 mm^−1
c = 20.087 (4) Å	T = 173 K
β = 92.94 (3)°	Block, colourless
V = 3239.1 (11) Å^3	0.20 × 0.20 × 0.10 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	5714 independent reflections
Radiation source: fine-focus sealed tube	4160 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
φ and ω scans	θmax = 25.0°, θmin = 3.4°
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	h = −12→12
Tmin = 0.965, Tmax = 0.982	k = −18→18
10563 measured reflections	l = −23→23

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0481P)^2 + 1.5999P] where P = (Fo^2 + 2Fc^2)/3
5714 reflections	(Δ/σ)max = 0.001
367 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.33 e Å^−3

Special details

Experimental. Spectroscopic analysis: ¹H NMR (300 MHz, 298 K, toluene-d₈, δ, p.p.m.): 7.87, 7.18 (m, 20H, C₆H₅), 2.12 (s, 2H, NH), 1.17 [s, 18H, C(CH₃)₃]; ¹³C NMR (300 MHz, 298 K, THF-d₈, δ, p.p.m.): 136.1–125.3 (C₆H₅), 54.4 [C(CH₃)₃], 38.9, [C(CH₃)₃]; ²⁹Si NMR (300 MHz, 298 K, toluene-d₈, δ, p.p.m.): -34.6, -66.6 [s, SiPh₂, Si(NH-^tBu)₂].

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.

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

	x	y	z	Uiso*/Ueq
Si1	0.44061 (6)	0.84847 (4)	0.15038 (3)	0.02615 (17)
Si2	0.47114 (6)	0.76505 (4)	0.28321 (3)	0.02708 (17)
Si3	0.53534 (6)	0.66909 (4)	0.16101 (3)	0.02892 (18)
O1	0.42577 (15)	0.84029 (9)	0.23087 (8)	0.0280 (4)
O2	0.54861 (15)	0.69361 (9)	0.24102 (8)	0.0300 (4)
O3	0.49510 (15)	0.75807 (9)	0.12311 (8)	0.0294 (4)
N1	0.6785 (2)	0.62967 (12)	0.13621 (11)	0.0380 (5)
H1A	0.6810	0.5741	0.1325	0.057*
N2	0.4094 (2)	0.60219 (12)	0.14210 (11)	0.0359 (5)
H2A	0.3506	0.6240	0.1136	0.054*
C1	0.5603 (2)	0.93426 (13)	0.13678 (12)	0.0271 (5)
C2	0.6207 (2)	0.97887 (15)	0.18976 (13)	0.0367 (6)
H2	0.5976	0.9665	0.2339	0.044*
C3	0.7142 (3)	1.04120 (16)	0.17945 (15)	0.0438 (7)
H3	0.7542	1.0709	0.2162	0.053*
C4	0.7480 (2)	1.05932 (16)	0.11562 (15)	0.0410 (7)
H4	0.8120	1.1015	0.1084	0.049*
C5	0.6894 (3)	1.01666 (15)	0.06199 (14)	0.0406 (7)
H5	0.7129	1.0294	0.0180	0.049*
C6	0.5959 (2)	0.95501 (14)	0.07267 (13)	0.0338 (6)
H6	0.5553	0.9263	0.0355	0.041*
C7	0.2784 (2)	0.86649 (14)	0.10742 (12)	0.0289 (5)
C8	0.1984 (3)	0.93300 (17)	0.12560 (13)	0.0416 (7)
H8	0.2278	0.9708	0.1600	0.050*
C9	0.0753 (3)	0.94488 (19)	0.09385 (15)	0.0502 (8)
H9	0.0212	0.9902	0.1070	0.060*
C10	0.0322 (3)	0.89113 (18)	0.04362 (14)	0.0446 (7)
H10	−0.0515	0.8994	0.0221	0.054*
C11	0.1095 (3)	0.82565 (17)	0.02454 (14)	0.0421 (7)
H11	0.0797	0.7887	−0.0104	0.051*
C12	0.2313 (2)	0.81332 (16)	0.05631 (13)	0.0367 (6)
H12	0.2840	0.7674	0.0429	0.044*
C13	0.3209 (2)	0.72330 (14)	0.31896 (12)	0.0286 (5)
C14	0.3263 (3)	0.67692 (18)	0.37800 (14)	0.0451 (7)
H14	0.4089	0.6668	0.4003	0.054*
C15	0.2151 (3)	0.64516 (19)	0.40504 (15)	0.0523 (8)
H15	0.2218	0.6143	0.4457	0.063*
C16	0.0950 (3)	0.65812 (18)	0.37333 (15)	0.0468 (7)
H16	0.0184	0.6360	0.3916	0.056*
C17	0.0868 (3)	0.7034 (2)	0.31485 (15)	0.0504 (8)
H17	0.0039	0.7125	0.2926	0.061*
C18	0.1980 (3)	0.73581 (18)	0.28808 (14)	0.0435 (7)
H18	0.1901	0.7673	0.2477	0.052*
C19	0.5854 (2)	0.80766 (14)	0.34997 (12)	0.0301 (5)
C20	0.5397 (3)	0.86022 (16)	0.39989 (13)	0.0402 (6)
H20	0.4490	0.8725	0.4003	0.048*
C21	0.6244 (3)	0.89467 (17)	0.44877 (14)	0.0475 (7)
H21	0.5916	0.9305	0.4821	0.057*
C22	0.7557 (3)	0.87696 (18)	0.44898 (15)	0.0487 (7)
H22	0.8137	0.9009	0.4823	0.058*
C23	0.8032 (3)	0.82485 (18)	0.40135 (15)	0.0480 (7)
H23	0.8939	0.8122	0.4020	0.058*
C24	0.7190 (2)	0.79058 (17)	0.35220 (13)	0.0396 (6)
H24	0.7532	0.7547	0.3193	0.047*
C25	0.7997 (2)	0.67347 (16)	0.11981 (13)	0.0373 (6)
C26	0.9158 (3)	0.6156 (2)	0.1352 (2)	0.0743 (11)
H26A	0.9200	0.6011	0.1827	0.111*
H26B	0.9964	0.6448	0.1242	0.111*
H26C	0.9060	0.5637	0.1086	0.111*
C27	0.7891 (4)	0.6963 (3)	0.04581 (16)	0.0823 (12)
H27A	0.7752	0.6446	0.0193	0.123*
H27B	0.8700	0.7240	0.0334	0.123*
H27C	0.7153	0.7350	0.0372	0.123*
C28	0.8178 (3)	0.75422 (16)	0.16022 (15)	0.0461 (7)
H28A	0.7468	0.7939	0.1481	0.069*
H28B	0.9018	0.7803	0.1509	0.069*
H28C	0.8165	0.7408	0.2078	0.069*
C29	0.3770 (2)	0.51545 (15)	0.16310 (14)	0.0369 (6)
C30	0.4793 (3)	0.48447 (18)	0.21524 (16)	0.0525 (8)
H30A	0.5652	0.4834	0.1959	0.079*
H30B	0.4565	0.4272	0.2297	0.079*
H30C	0.4819	0.5229	0.2536	0.079*
C31	0.3725 (4)	0.45626 (18)	0.10318 (16)	0.0609 (9)
H31A	0.3024	0.4742	0.0712	0.091*
H31B	0.3556	0.3982	0.1179	0.091*
H31C	0.4563	0.4583	0.0819	0.091*
C32	0.2430 (3)	0.51695 (19)	0.19301 (17)	0.0577 (9)
H32A	0.2447	0.5564	0.2307	0.087*
H32B	0.2213	0.4599	0.2084	0.087*
H32C	0.1770	0.5355	0.1591	0.087*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0272 (4)	0.0257 (3)	0.0258 (4)	0.0003 (3)	0.0034 (3)	0.0016 (3)
Si2	0.0254 (4)	0.0282 (3)	0.0278 (4)	0.0010 (3)	0.0029 (3)	0.0036 (3)
Si3	0.0277 (4)	0.0253 (3)	0.0343 (4)	−0.0004 (3)	0.0074 (3)	−0.0006 (3)
O1	0.0330 (9)	0.0268 (8)	0.0248 (9)	0.0047 (7)	0.0053 (7)	0.0032 (7)
O2	0.0276 (9)	0.0286 (8)	0.0341 (10)	0.0041 (7)	0.0028 (7)	0.0019 (7)
O3	0.0332 (9)	0.0260 (8)	0.0295 (9)	0.0010 (7)	0.0059 (7)	−0.0005 (7)
N1	0.0371 (13)	0.0268 (10)	0.0514 (14)	0.0035 (9)	0.0168 (11)	0.0006 (10)
N2	0.0354 (12)	0.0309 (11)	0.0410 (13)	−0.0040 (9)	−0.0014 (10)	0.0070 (9)
C1	0.0272 (13)	0.0241 (11)	0.0301 (13)	0.0058 (9)	0.0028 (10)	0.0023 (10)
C2	0.0400 (16)	0.0373 (14)	0.0322 (15)	−0.0039 (11)	−0.0038 (12)	0.0036 (11)
C3	0.0394 (16)	0.0399 (15)	0.0507 (18)	−0.0077 (12)	−0.0108 (13)	−0.0016 (13)
C4	0.0282 (14)	0.0333 (13)	0.062 (2)	−0.0037 (11)	0.0058 (13)	0.0031 (13)
C5	0.0422 (16)	0.0347 (14)	0.0466 (17)	−0.0016 (12)	0.0183 (13)	0.0048 (12)
C6	0.0395 (15)	0.0299 (13)	0.0325 (15)	−0.0010 (11)	0.0060 (12)	−0.0025 (11)
C7	0.0278 (13)	0.0310 (12)	0.0282 (14)	−0.0026 (10)	0.0049 (10)	0.0053 (10)
C8	0.0404 (16)	0.0505 (16)	0.0333 (15)	0.0090 (12)	−0.0023 (12)	−0.0047 (12)
C9	0.0388 (17)	0.0641 (19)	0.0479 (18)	0.0195 (14)	0.0034 (14)	−0.0007 (15)
C10	0.0331 (15)	0.0559 (17)	0.0442 (17)	−0.0046 (13)	−0.0054 (13)	0.0083 (14)
C11	0.0406 (16)	0.0412 (15)	0.0436 (17)	−0.0121 (12)	−0.0072 (13)	0.0040 (13)
C12	0.0363 (15)	0.0324 (13)	0.0411 (16)	−0.0045 (11)	−0.0017 (12)	0.0028 (11)
C13	0.0271 (13)	0.0299 (12)	0.0289 (13)	−0.0015 (10)	0.0036 (10)	−0.0015 (10)
C14	0.0333 (15)	0.0595 (17)	0.0419 (17)	−0.0089 (13)	−0.0031 (12)	0.0189 (14)
C15	0.0449 (18)	0.0647 (19)	0.0476 (18)	−0.0138 (14)	0.0064 (14)	0.0192 (15)
C16	0.0376 (16)	0.0528 (17)	0.0512 (18)	−0.0140 (13)	0.0149 (14)	−0.0025 (14)
C17	0.0275 (15)	0.073 (2)	0.0507 (19)	−0.0048 (14)	0.0005 (13)	−0.0012 (16)
C18	0.0345 (15)	0.0592 (17)	0.0370 (16)	0.0029 (13)	0.0028 (12)	0.0083 (13)
C19	0.0327 (14)	0.0284 (12)	0.0295 (14)	−0.0019 (10)	0.0031 (11)	0.0062 (10)
C20	0.0411 (16)	0.0391 (14)	0.0404 (16)	0.0054 (12)	0.0022 (13)	−0.0017 (12)
C21	0.065 (2)	0.0408 (15)	0.0367 (16)	−0.0040 (14)	0.0026 (14)	−0.0085 (13)
C22	0.054 (2)	0.0464 (16)	0.0442 (18)	−0.0136 (14)	−0.0075 (14)	−0.0013 (14)
C23	0.0363 (16)	0.0600 (18)	0.0474 (18)	−0.0078 (13)	−0.0006 (13)	−0.0041 (15)
C24	0.0319 (15)	0.0477 (16)	0.0394 (16)	−0.0029 (12)	0.0035 (12)	−0.0041 (12)
C25	0.0281 (14)	0.0451 (15)	0.0396 (15)	−0.0015 (11)	0.0108 (11)	−0.0038 (12)
C26	0.0378 (18)	0.058 (2)	0.128 (3)	0.0112 (15)	0.013 (2)	−0.014 (2)
C27	0.083 (3)	0.124 (3)	0.041 (2)	−0.053 (2)	0.0147 (18)	−0.002 (2)
C28	0.0361 (15)	0.0423 (15)	0.0604 (19)	−0.0039 (12)	0.0073 (14)	−0.0034 (14)
C29	0.0352 (15)	0.0283 (13)	0.0468 (16)	−0.0032 (11)	−0.0003 (12)	0.0030 (12)
C30	0.0494 (18)	0.0463 (16)	0.061 (2)	−0.0084 (13)	−0.0099 (15)	0.0204 (15)
C31	0.081 (2)	0.0387 (16)	0.062 (2)	−0.0022 (15)	−0.0047 (18)	−0.0060 (15)
C32	0.0445 (18)	0.0525 (18)	0.077 (2)	−0.0071 (14)	0.0125 (16)	0.0155 (16)

Geometric parameters (Å, º)

Si1—O3	1.6349 (16)	C15—C16	1.372 (4)
Si1—O1	1.6366 (17)	C15—H15	0.9500
Si1—C7	1.855 (2)	C16—C17	1.373 (4)
Si1—C1	1.855 (2)	C16—H16	0.9500
Si2—O1	1.6363 (16)	C17—C18	1.382 (4)
Si2—O2	1.6386 (16)	C17—H17	0.9500
Si2—C13	1.852 (2)	C18—H18	0.9500
Si2—C19	1.860 (3)	C19—C24	1.394 (3)
Si3—O3	1.6382 (16)	C19—C20	1.400 (3)
Si3—O2	1.6518 (18)	C20—C21	1.387 (4)
Si3—N1	1.691 (2)	C20—H20	0.9500
Si3—N2	1.694 (2)	C21—C22	1.374 (4)
N1—C25	1.473 (3)	C21—H21	0.9500
N1—H1A	0.8800	C22—C23	1.369 (4)
N2—C29	1.473 (3)	C22—H22	0.9500
N2—H2A	0.8800	C23—C24	1.386 (4)
C1—C2	1.393 (3)	C23—H23	0.9500
C1—C6	1.395 (3)	C24—H24	0.9500
C2—C3	1.395 (3)	C25—C28	1.516 (4)
C2—H2	0.9500	C25—C26	1.518 (4)
C3—C4	1.375 (4)	C25—C27	1.528 (4)
C3—H3	0.9500	C26—H26A	0.9800
C4—C5	1.381 (4)	C26—H26B	0.9800
C4—H4	0.9500	C26—H26C	0.9800
C5—C6	1.389 (3)	C27—H27A	0.9800
C5—H5	0.9500	C27—H27B	0.9800
C6—H6	0.9500	C27—H27C	0.9800
C7—C8	1.391 (3)	C28—H28A	0.9800
C7—C12	1.392 (3)	C28—H28B	0.9800
C8—C9	1.396 (4)	C28—H28C	0.9800
C8—H8	0.9500	C29—C31	1.522 (4)
C9—C10	1.373 (4)	C29—C30	1.523 (4)
C9—H9	0.9500	C29—C32	1.527 (4)
C10—C11	1.367 (4)	C30—H30A	0.9800
C10—H10	0.9500	C30—H30B	0.9800
C11—C12	1.386 (4)	C30—H30C	0.9800
C11—H11	0.9500	C31—H31A	0.9800
C12—H12	0.9500	C31—H31B	0.9800
C13—C18	1.389 (4)	C31—H31C	0.9800
C13—C14	1.392 (3)	C32—H32A	0.9800
C14—C15	1.381 (4)	C32—H32B	0.9800
C14—H14	0.9500	C32—H32C	0.9800
O3—Si1—O1	108.24 (8)	C17—C16—H16	120.4
O3—Si1—C7	106.90 (10)	C16—C17—C18	120.6 (3)
O1—Si1—C7	110.19 (10)	C16—C17—H17	119.7
O3—Si1—C1	110.24 (10)	C18—C17—H17	119.7
O1—Si1—C1	107.37 (10)	C17—C18—C13	121.3 (3)
C7—Si1—C1	113.79 (10)	C17—C18—H18	119.3
O1—Si2—O2	107.15 (9)	C13—C18—H18	119.3
O1—Si2—C13	106.99 (10)	C24—C19—C20	117.1 (2)
O2—Si2—C13	113.00 (9)	C24—C19—Si2	122.31 (19)
O1—Si2—C19	110.44 (10)	C20—C19—Si2	120.56 (19)
O2—Si2—C19	108.49 (10)	C21—C20—C19	121.2 (3)
C13—Si2—C19	110.71 (11)	C21—C20—H20	119.4
O3—Si3—O2	104.96 (8)	C19—C20—H20	119.4
O3—Si3—N1	112.27 (10)	C22—C21—C20	120.0 (3)
O2—Si3—N1	110.07 (10)	C22—C21—H21	120.0
O3—Si3—N2	104.95 (10)	C20—C21—H21	120.0
O2—Si3—N2	112.79 (10)	C23—C22—C21	120.2 (3)
N1—Si3—N2	111.56 (11)	C23—C22—H22	119.9
Si2—O1—Si1	130.85 (10)	C21—C22—H22	119.9
Si2—O2—Si3	130.24 (10)	C22—C23—C24	120.1 (3)
Si1—O3—Si3	132.25 (11)	C22—C23—H23	120.0
C25—N1—Si3	130.37 (17)	C24—C23—H23	120.0
C25—N1—H1A	114.8	C23—C24—C19	121.4 (3)
Si3—N1—H1A	114.8	C23—C24—H24	119.3
C29—N2—Si3	133.88 (17)	C19—C24—H24	119.3
C29—N2—H2A	113.1	N1—C25—C28	110.8 (2)
Si3—N2—H2A	113.1	N1—C25—C26	109.5 (2)
C2—C1—C6	117.4 (2)	C28—C25—C26	108.8 (2)
C2—C1—Si1	121.75 (18)	N1—C25—C27	108.0 (2)
C6—C1—Si1	120.85 (18)	C28—C25—C27	108.9 (3)
C1—C2—C3	121.5 (2)	C26—C25—C27	110.8 (3)
C1—C2—H2	119.2	C25—C26—H26A	109.5
C3—C2—H2	119.2	C25—C26—H26B	109.5
C4—C3—C2	119.5 (3)	H26A—C26—H26B	109.5
C4—C3—H3	120.2	C25—C26—H26C	109.5
C2—C3—H3	120.2	H26A—C26—H26C	109.5
C3—C4—C5	120.4 (2)	H26B—C26—H26C	109.5
C3—C4—H4	119.8	C25—C27—H27A	109.5
C5—C4—H4	119.8	C25—C27—H27B	109.5
C4—C5—C6	119.7 (2)	H27A—C27—H27B	109.5
C4—C5—H5	120.1	C25—C27—H27C	109.5
C6—C5—H5	120.1	H27A—C27—H27C	109.5
C5—C6—C1	121.4 (2)	H27B—C27—H27C	109.5
C5—C6—H6	119.3	C25—C28—H28A	109.5
C1—C6—H6	119.3	C25—C28—H28B	109.5
C8—C7—C12	117.4 (2)	H28A—C28—H28B	109.5
C8—C7—Si1	121.30 (19)	C25—C28—H28C	109.5
C12—C7—Si1	121.29 (19)	H28A—C28—H28C	109.5
C7—C8—C9	120.8 (3)	H28B—C28—H28C	109.5
C7—C8—H8	119.6	N2—C29—C31	109.9 (2)
C9—C8—H8	119.6	N2—C29—C30	109.7 (2)
C10—C9—C8	120.1 (3)	C31—C29—C30	109.8 (2)
C10—C9—H9	119.9	N2—C29—C32	108.6 (2)
C8—C9—H9	119.9	C31—C29—C32	109.2 (2)
C11—C10—C9	120.2 (3)	C30—C29—C32	109.6 (2)
C11—C10—H10	119.9	C29—C30—H30A	109.5
C9—C10—H10	119.9	C29—C30—H30B	109.5
C10—C11—C12	119.8 (3)	H30A—C30—H30B	109.5
C10—C11—H11	120.1	C29—C30—H30C	109.5
C12—C11—H11	120.1	H30A—C30—H30C	109.5
C11—C12—C7	121.7 (2)	H30B—C30—H30C	109.5
C11—C12—H12	119.2	C29—C31—H31A	109.5
C7—C12—H12	119.2	C29—C31—H31B	109.5
C18—C13—C14	116.8 (2)	H31A—C31—H31B	109.5
C18—C13—Si2	121.93 (19)	C29—C31—H31C	109.5
C14—C13—Si2	121.29 (19)	H31A—C31—H31C	109.5
C15—C14—C13	121.9 (3)	H31B—C31—H31C	109.5
C15—C14—H14	119.1	C29—C32—H32A	109.5
C13—C14—H14	119.1	C29—C32—H32B	109.5
C16—C15—C14	120.1 (3)	H32A—C32—H32B	109.5
C16—C15—H15	119.9	C29—C32—H32C	109.5
C14—C15—H15	119.9	H32A—C32—H32C	109.5
C15—C16—C17	119.3 (3)	H32B—C32—H32C	109.5
C15—C16—H16	120.4