A low-temperature modification of hexa-tert-butyl­disilane and a new polymorph of 1,1,2,2-tetra-tert-butyl-1,2-di­phenyl­disilane

Crystals of hexa-tert-butyl­disilane, C₂₄H₅₄Si₂, undergo a reversible phase transition at 179 (2) K. The space group changes from Ibca (high temperature) to Pbca (low temperature), but the lattice constants a, b and c do not change significantly during the phase transition. The crystallographic twofold axis of the mol­ecule in the high-temperature phase is replaced by a noncrystallographic twofold axis in the low-temperature phase. The angle between the two axes is 2.36 (4)°. The centre of the mol­ecule undergoes a translation of 0.123 (1) Å during the phase transition, but the conformation angles of the mol­ecule remain unchanged. Between the two tri-tert-butyl­silyl subunits there are six short repulsive intra­molecular C—H...H—C contacts, with H...H distances between 2.02 and 2.04 Å, resulting in a significant lengthening of the Si—Si and Si—C bonds. The Si—Si bond length is 2.6863 (5) Å and the Si—C bond lengths are between 1.9860 (14) and 1.9933 (14) Å. Torsion angles about the Si—Si and Si—C bonds deviate by approximately 15° from the values expected for staggered conformations due to intra­molecular steric H...H repulsions. A new polymorph is reported for the crystal structure of 1,1,2,2-tetra-tert-butyl-1,2-di­phenyl­disilane, C₂₈H₄₆Si₂. It has two independent mol­ecules with rather similar conformations. The Si—Si bond lengths are 2.4869 (8) and 2.4944 (8) Å. The C—Si—Si—C torsion angles deviate by between −3.4 (1) and −18.5 (1)° from the values expected for a staggered conformation. These deviations result from steric inter­actions. Four Si—C(t-Bu) bonds are almost staggered, while the other four Si—C(t-Bu) bonds are inter­mediate between a staggered and an eclipsed conformation. The latter Si—C(t-Bu) bonds are about 0.019 (2) Å longer than the staggered Si—C(t-Bu) bonds.

Computing details

For both compounds, data collection: SMART (Siemens, 1995); cell refinement: SMART (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

(I) Hexa-tert-butyldisilane

Crystal data

C24H54Si2	F(000) = 1808
Mr = 398.85	Dx = 1.015 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 371 reflections
a = 11.2923 (8) Å	θ = 3–26°
b = 29.204 (3) Å	µ = 0.14 mm^−1
c = 15.8321 (16) Å	T = 147 K
V = 5221.1 (8) Å^3	Rod, colorless
Z = 8	0.75 × 0.27 × 0.14 mm

Data collection

Siemens SMART 1K CCD diffractometer	7483 independent reflections
Radiation source: normal-focus sealed tube	4986 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
ω scans	θmax = 30.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −15→15
Tmin = 0.856, Tmax = 0.980	k = −41→41
58910 measured reflections	l = −21→20

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.05P)^2 + 0.8P] where P = (Fo^2 + 2Fc^2)/3
7483 reflections	(Δ/σ)max = 0.001
253 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

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	0.17754 (3)	0.124481 (12)	0.56117 (2)	0.01561 (10)
Si2	0.34409 (3)	0.127976 (12)	0.44019 (2)	0.01567 (10)
C1	0.01469 (12)	0.13043 (5)	0.51447 (10)	0.0243 (3)
C2	−0.08188 (13)	0.11645 (7)	0.57885 (11)	0.0399 (4)
H2A	−0.1602	0.1234	0.5555	0.060*
H2B	−0.0705	0.1335	0.6315	0.060*
H2C	−0.0761	0.0835	0.5903	0.060*
C3	−0.01244 (13)	0.18029 (5)	0.48846 (11)	0.0329 (4)
H3A	−0.0930	0.1821	0.4657	0.049*
H3B	0.0442	0.1901	0.4452	0.049*
H3C	−0.0057	0.2003	0.5379	0.049*
C4	−0.00989 (13)	0.10131 (5)	0.43568 (10)	0.0311 (4)
H4A	−0.0910	0.1068	0.4163	0.047*
H4B	−0.0002	0.0688	0.4496	0.047*
H4C	0.0459	0.1097	0.3909	0.047*
C5	0.18333 (13)	0.06576 (5)	0.62495 (9)	0.0247 (3)
C6	0.30907 (14)	0.05040 (5)	0.64885 (10)	0.0318 (4)
H6A	0.3053	0.0209	0.6783	0.048*
H6B	0.3452	0.0733	0.6860	0.048*
H6C	0.3569	0.0472	0.5975	0.048*
C7	0.11442 (15)	0.06725 (6)	0.70932 (10)	0.0369 (4)
H7A	0.1138	0.0367	0.7348	0.055*
H7B	0.0329	0.0772	0.6987	0.055*
H7C	0.1529	0.0888	0.7479	0.055*
C8	0.12939 (16)	0.02598 (5)	0.57365 (11)	0.0371 (4)
H8A	0.1357	−0.0025	0.6062	0.056*
H8B	0.1724	0.0227	0.5202	0.056*
H8C	0.0458	0.0325	0.5620	0.056*
C9	0.19898 (12)	0.17452 (5)	0.64523 (9)	0.0225 (3)
C10	0.08987 (14)	0.18213 (6)	0.70264 (10)	0.0352 (4)
H10A	0.1092	0.2047	0.7462	0.053*
H10B	0.0678	0.1531	0.7295	0.053*
H10C	0.0235	0.1933	0.6685	0.053*
C11	0.30305 (13)	0.16440 (5)	0.70498 (10)	0.0286 (3)
H11A	0.3143	0.1903	0.7435	0.043*
H11B	0.3753	0.1597	0.6718	0.043*
H11C	0.2859	0.1367	0.7378	0.043*
C12	0.22530 (14)	0.22154 (5)	0.60588 (11)	0.0318 (4)
H12A	0.2375	0.2441	0.6509	0.048*
H12B	0.1583	0.2310	0.5706	0.048*
H12C	0.2969	0.2195	0.5711	0.048*
C13	0.31336 (12)	0.17872 (5)	0.35889 (9)	0.0229 (3)
C14	0.27842 (14)	0.22426 (5)	0.40074 (11)	0.0310 (4)
H14A	0.2625	0.2472	0.3570	0.047*
H14B	0.3433	0.2349	0.4369	0.047*
H14C	0.2071	0.2197	0.4350	0.047*
C15	0.21142 (13)	0.16659 (5)	0.29861 (10)	0.0285 (3)
H15A	0.1950	0.1927	0.2616	0.043*
H15B	0.1404	0.1593	0.3315	0.043*
H15C	0.2338	0.1400	0.2643	0.043*
C16	0.42090 (14)	0.19045 (6)	0.30226 (11)	0.0348 (4)
H16A	0.3971	0.2129	0.2595	0.052*
H16B	0.4491	0.1626	0.2743	0.052*
H16C	0.4845	0.2033	0.3371	0.052*
C17	0.34969 (13)	0.07047 (5)	0.37334 (9)	0.0251 (3)
C18	0.22682 (15)	0.05198 (5)	0.34840 (10)	0.0329 (4)
H18A	0.2361	0.0230	0.3180	0.049*
H18B	0.1868	0.0743	0.3120	0.049*
H18C	0.1794	0.0469	0.3994	0.049*
C19	0.41818 (15)	0.07537 (6)	0.28926 (10)	0.0372 (4)
H19A	0.4261	0.0452	0.2626	0.056*
H19B	0.4970	0.0880	0.3005	0.056*
H19C	0.3749	0.0960	0.2514	0.056*
C20	0.41077 (15)	0.03161 (5)	0.42263 (10)	0.0355 (4)
H20A	0.4088	0.0034	0.3890	0.053*
H20B	0.3692	0.0266	0.4762	0.053*
H20C	0.4932	0.0401	0.4341	0.053*
C21	0.50546 (12)	0.13774 (5)	0.48782 (9)	0.0240 (3)
C22	0.53571 (13)	0.10779 (5)	0.56483 (10)	0.0299 (4)
H22A	0.6143	0.1161	0.5861	0.045*
H22B	0.5355	0.0755	0.5482	0.045*
H22C	0.4766	0.1127	0.6092	0.045*
C23	0.52267 (13)	0.18761 (5)	0.51742 (11)	0.0335 (4)
H23A	0.6032	0.1915	0.5393	0.050*
H23B	0.4654	0.1946	0.5621	0.050*
H23C	0.5103	0.2084	0.4697	0.050*
C24	0.60486 (13)	0.12825 (6)	0.42309 (11)	0.0392 (4)
H24A	0.6814	0.1369	0.4475	0.059*
H24B	0.5905	0.1462	0.3718	0.059*
H24C	0.6057	0.0956	0.4089	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.01472 (17)	0.01753 (17)	0.0146 (2)	−0.00121 (13)	0.00001 (14)	−0.00181 (15)
Si2	0.01544 (18)	0.01680 (17)	0.0148 (2)	0.00162 (13)	0.00021 (14)	0.00224 (15)
C1	0.0155 (7)	0.0341 (8)	0.0232 (8)	−0.0015 (6)	−0.0008 (6)	−0.0032 (6)
C2	0.0167 (7)	0.0689 (12)	0.0343 (10)	−0.0051 (7)	0.0029 (7)	−0.0034 (9)
C3	0.0217 (7)	0.0410 (9)	0.0360 (10)	0.0110 (7)	−0.0062 (7)	−0.0053 (8)
C4	0.0246 (8)	0.0420 (9)	0.0267 (9)	−0.0084 (6)	−0.0055 (7)	−0.0046 (7)
C5	0.0310 (8)	0.0237 (7)	0.0194 (8)	−0.0057 (6)	0.0018 (6)	0.0041 (6)
C6	0.0418 (9)	0.0258 (7)	0.0278 (9)	0.0021 (7)	0.0003 (7)	0.0086 (7)
C7	0.0421 (10)	0.0425 (9)	0.0262 (10)	−0.0071 (8)	0.0076 (8)	0.0113 (8)
C8	0.0523 (10)	0.0229 (7)	0.0359 (11)	−0.0147 (7)	0.0008 (8)	0.0045 (7)
C9	0.0224 (7)	0.0248 (7)	0.0204 (8)	0.0039 (5)	−0.0027 (6)	−0.0077 (6)
C10	0.0311 (8)	0.0481 (10)	0.0265 (9)	0.0087 (7)	0.0023 (7)	−0.0161 (8)
C11	0.0304 (8)	0.0339 (8)	0.0216 (9)	0.0010 (6)	−0.0077 (6)	−0.0082 (7)
C12	0.0376 (9)	0.0222 (7)	0.0355 (10)	0.0023 (6)	−0.0063 (7)	−0.0096 (7)
C13	0.0241 (7)	0.0244 (7)	0.0201 (8)	−0.0009 (6)	−0.0012 (6)	0.0086 (6)
C14	0.0365 (9)	0.0210 (7)	0.0355 (10)	−0.0007 (6)	−0.0060 (7)	0.0081 (7)
C15	0.0304 (8)	0.0326 (8)	0.0225 (9)	0.0007 (6)	−0.0067 (7)	0.0087 (7)
C16	0.0313 (8)	0.0432 (9)	0.0299 (10)	−0.0051 (7)	0.0027 (7)	0.0183 (8)
C17	0.0336 (8)	0.0240 (7)	0.0178 (8)	0.0080 (6)	0.0030 (6)	−0.0025 (6)
C18	0.0464 (10)	0.0260 (8)	0.0264 (9)	−0.0011 (7)	−0.0014 (7)	−0.0081 (7)
C19	0.0458 (10)	0.0431 (9)	0.0226 (9)	0.0116 (8)	0.0090 (8)	−0.0064 (7)
C20	0.0504 (10)	0.0252 (8)	0.0310 (10)	0.0160 (7)	0.0034 (8)	−0.0035 (7)
C21	0.0156 (7)	0.0332 (7)	0.0233 (8)	0.0011 (6)	0.0010 (6)	0.0066 (6)
C22	0.0217 (7)	0.0416 (9)	0.0264 (9)	0.0056 (6)	−0.0032 (6)	0.0060 (7)
C23	0.0236 (8)	0.0383 (9)	0.0386 (10)	−0.0127 (6)	−0.0069 (7)	0.0080 (8)
C24	0.0182 (7)	0.0663 (12)	0.0329 (10)	0.0034 (7)	0.0030 (7)	0.0115 (9)

Geometric parameters (Å, º)

Si1—C1	1.9895 (14)	C12—H12A	0.9800
Si1—C5	1.9911 (14)	C12—H12B	0.9800
Si1—C9	1.9913 (14)	C12—H12C	0.9800
Si1—Si2	2.6863 (5)	C13—C15	1.537 (2)
Si2—C17	1.9860 (14)	C13—C14	1.537 (2)
Si2—C21	1.9926 (14)	C13—C16	1.548 (2)
Si2—C13	1.9933 (14)	C14—H14A	0.9800
C1—C4	1.535 (2)	C14—H14B	0.9800
C1—C3	1.544 (2)	C14—H14C	0.9800
C1—C2	1.548 (2)	C15—H15A	0.9800
C2—H2A	0.9800	C15—H15B	0.9800
C2—H2B	0.9800	C15—H15C	0.9800
C2—H2C	0.9800	C16—H16A	0.9800
C3—H3A	0.9800	C16—H16B	0.9800
C3—H3B	0.9800	C16—H16C	0.9800
C3—H3C	0.9800	C17—C20	1.5404 (19)
C4—H4A	0.9800	C17—C18	1.540 (2)
C4—H4B	0.9800	C17—C19	1.546 (2)
C4—H4C	0.9800	C18—H18A	0.9800
C5—C6	1.536 (2)	C18—H18B	0.9800
C5—C8	1.543 (2)	C18—H18C	0.9800
C5—C7	1.546 (2)	C19—H19A	0.9800
C6—H6A	0.9800	C19—H19B	0.9800
C6—H6B	0.9800	C19—H19C	0.9800
C6—H6C	0.9800	C20—H20A	0.9800
C7—H7A	0.9800	C20—H20B	0.9800
C7—H7B	0.9800	C20—H20C	0.9800
C7—H7C	0.9800	C21—C22	1.539 (2)
C8—H8A	0.9800	C21—C23	1.542 (2)
C8—H8B	0.9800	C21—C24	1.545 (2)
C8—H8C	0.9800	C22—H22A	0.9800
C9—C12	1.537 (2)	C22—H22B	0.9800
C9—C11	1.5373 (19)	C22—H22C	0.9800
C9—C10	1.547 (2)	C23—H23A	0.9800
C10—H10A	0.9800	C23—H23B	0.9800
C10—H10B	0.9800	C23—H23C	0.9800
C10—H10C	0.9800	C24—H24A	0.9800
C11—H11A	0.9800	C24—H24B	0.9800
C11—H11B	0.9800	C24—H24C	0.9800
C11—H11C	0.9800
C1—Si1—C5	107.10 (6)	C9—C12—H12A	109.5
C1—Si1—C9	107.26 (6)	C9—C12—H12B	109.5
C5—Si1—C9	106.80 (6)	H12A—C12—H12B	109.5
C1—Si1—Si2	112.26 (5)	C9—C12—H12C	109.5
C5—Si1—Si2	111.80 (5)	H12A—C12—H12C	109.5
C9—Si1—Si2	111.32 (5)	H12B—C12—H12C	109.5
C17—Si2—C21	107.07 (6)	C15—C13—C14	105.96 (12)
C17—Si2—C13	106.87 (6)	C15—C13—C16	106.19 (13)
C21—Si2—C13	107.29 (6)	C14—C13—C16	105.04 (12)
C17—Si2—Si1	111.72 (5)	C15—C13—Si2	111.10 (9)
C21—Si2—Si1	112.08 (5)	C14—C13—Si2	114.18 (10)
C13—Si2—Si1	111.51 (4)	C16—C13—Si2	113.70 (10)
C4—C1—C3	105.65 (12)	C13—C14—H14A	109.5
C4—C1—C2	105.17 (12)	C13—C14—H14B	109.5
C3—C1—C2	106.54 (12)	H14A—C14—H14B	109.5
C4—C1—Si1	114.88 (10)	C13—C14—H14C	109.5
C3—C1—Si1	111.40 (9)	H14A—C14—H14C	109.5
C2—C1—Si1	112.56 (11)	H14B—C14—H14C	109.5
C1—C2—H2A	109.5	C13—C15—H15A	109.5
C1—C2—H2B	109.5	C13—C15—H15B	109.5
H2A—C2—H2B	109.5	H15A—C15—H15B	109.5
C1—C2—H2C	109.5	C13—C15—H15C	109.5
H2A—C2—H2C	109.5	H15A—C15—H15C	109.5
H2B—C2—H2C	109.5	H15B—C15—H15C	109.5
C1—C3—H3A	109.5	C13—C16—H16A	109.5
C1—C3—H3B	109.5	C13—C16—H16B	109.5
H3A—C3—H3B	109.5	H16A—C16—H16B	109.5
C1—C3—H3C	109.5	C13—C16—H16C	109.5
H3A—C3—H3C	109.5	H16A—C16—H16C	109.5
H3B—C3—H3C	109.5	H16B—C16—H16C	109.5
C1—C4—H4A	109.5	C20—C17—C18	105.95 (13)
C1—C4—H4B	109.5	C20—C17—C19	106.28 (12)
H4A—C4—H4B	109.5	C18—C17—C19	105.20 (13)
C1—C4—H4C	109.5	C20—C17—Si2	111.55 (10)
H4A—C4—H4C	109.5	C18—C17—Si2	113.86 (10)
H4B—C4—H4C	109.5	C19—C17—Si2	113.36 (10)
C6—C5—C8	105.94 (13)	C17—C18—H18A	109.5
C6—C5—C7	105.10 (13)	C17—C18—H18B	109.5
C8—C5—C7	106.09 (12)	H18A—C18—H18B	109.5
C6—C5—Si1	114.00 (10)	C17—C18—H18C	109.5
C8—C5—Si1	111.63 (10)	H18A—C18—H18C	109.5
C7—C5—Si1	113.41 (10)	H18B—C18—H18C	109.5
C5—C6—H6A	109.5	C17—C19—H19A	109.5
C5—C6—H6B	109.5	C17—C19—H19B	109.5
H6A—C6—H6B	109.5	H19A—C19—H19B	109.5
C5—C6—H6C	109.5	C17—C19—H19C	109.5
H6A—C6—H6C	109.5	H19A—C19—H19C	109.5
H6B—C6—H6C	109.5	H19B—C19—H19C	109.5
C5—C7—H7A	109.5	C17—C20—H20A	109.5
C5—C7—H7B	109.5	C17—C20—H20B	109.5
H7A—C7—H7B	109.5	H20A—C20—H20B	109.5
C5—C7—H7C	109.5	C17—C20—H20C	109.5
H7A—C7—H7C	109.5	H20A—C20—H20C	109.5
H7B—C7—H7C	109.5	H20B—C20—H20C	109.5
C5—C8—H8A	109.5	C22—C21—C23	105.54 (13)
C5—C8—H8B	109.5	C22—C21—C24	105.20 (12)
H8A—C8—H8B	109.5	C23—C21—C24	106.23 (12)
C5—C8—H8C	109.5	C22—C21—Si2	114.93 (10)
H8A—C8—H8C	109.5	C23—C21—Si2	111.43 (9)
H8B—C8—H8C	109.5	C24—C21—Si2	112.81 (11)
C12—C9—C11	105.86 (12)	C21—C22—H22A	109.5
C12—C9—C10	105.29 (12)	C21—C22—H22B	109.5
C11—C9—C10	105.96 (13)	H22A—C22—H22B	109.5
C12—C9—Si1	114.09 (10)	C21—C22—H22C	109.5
C11—C9—Si1	111.29 (9)	H22A—C22—H22C	109.5
C10—C9—Si1	113.66 (10)	H22B—C22—H22C	109.5
C9—C10—H10A	109.5	C21—C23—H23A	109.5
C9—C10—H10B	109.5	C21—C23—H23B	109.5
H10A—C10—H10B	109.5	H23A—C23—H23B	109.5
C9—C10—H10C	109.5	C21—C23—H23C	109.5
H10A—C10—H10C	109.5	H23A—C23—H23C	109.5
H10B—C10—H10C	109.5	H23B—C23—H23C	109.5
C9—C11—H11A	109.5	C21—C24—H24A	109.5
C9—C11—H11B	109.5	C21—C24—H24B	109.5
H11A—C11—H11B	109.5	H24A—C24—H24B	109.5
C9—C11—H11C	109.5	C21—C24—H24C	109.5
H11A—C11—H11C	109.5	H24A—C24—H24C	109.5
H11B—C11—H11C	109.5	H24B—C24—H24C	109.5
C1—Si1—Si2—C17	−74.14 (7)	Si2—Si1—C9—C11	−75.23 (11)
C5—Si1—Si2—C17	46.25 (7)	C1—Si1—C9—C10	42.06 (12)
C9—Si1—Si2—C17	165.61 (6)	C5—Si1—C9—C10	−72.48 (12)
C1—Si1—Si2—C21	165.69 (7)	Si2—Si1—C9—C10	165.23 (10)
C5—Si1—Si2—C21	−73.92 (7)	C17—Si2—C13—C15	47.20 (12)
C9—Si1—Si2—C21	45.43 (7)	C21—Si2—C13—C15	161.76 (10)
C1—Si1—Si2—C13	45.38 (7)	Si1—Si2—C13—C15	−75.16 (11)
C5—Si1—Si2—C13	165.77 (6)	C17—Si2—C13—C14	166.96 (10)
C9—Si1—Si2—C13	−74.87 (7)	C21—Si2—C13—C14	−78.48 (11)
C5—Si1—C1—C4	−77.84 (12)	Si1—Si2—C13—C14	44.60 (11)
C9—Si1—C1—C4	167.82 (11)	C17—Si2—C13—C16	−72.53 (12)
Si2—Si1—C1—C4	45.24 (11)	C21—Si2—C13—C16	42.04 (13)
C5—Si1—C1—C3	162.08 (10)	Si1—Si2—C13—C16	165.12 (10)
C9—Si1—C1—C3	47.74 (12)	C21—Si2—C17—C20	47.24 (12)
Si2—Si1—C1—C3	−74.84 (11)	C13—Si2—C17—C20	161.95 (11)
C5—Si1—C1—C2	42.49 (12)	Si1—Si2—C17—C20	−75.82 (11)
C9—Si1—C1—C2	−71.85 (12)	C21—Si2—C17—C18	167.10 (11)
Si2—Si1—C1—C2	165.57 (10)	C13—Si2—C17—C18	−78.19 (12)
C1—Si1—C5—C6	167.25 (11)	Si1—Si2—C17—C18	44.03 (12)
C9—Si1—C5—C6	−78.10 (12)	C21—Si2—C17—C19	−72.68 (12)
Si2—Si1—C5—C6	43.88 (12)	C13—Si2—C17—C19	42.03 (12)
C1—Si1—C5—C8	47.25 (12)	Si1—Si2—C17—C19	164.26 (9)
C9—Si1—C5—C8	161.90 (11)	C17—Si2—C21—C22	−77.39 (12)
Si2—Si1—C5—C8	−76.11 (11)	C13—Si2—C21—C22	168.19 (11)
C1—Si1—C5—C7	−72.52 (12)	Si1—Si2—C21—C22	45.46 (12)
C9—Si1—C5—C7	42.13 (12)	C17—Si2—C21—C23	162.61 (10)
Si2—Si1—C5—C7	164.11 (9)	C13—Si2—C21—C23	48.19 (12)
C1—Si1—C9—C12	−78.69 (11)	Si1—Si2—C21—C23	−74.54 (11)
C5—Si1—C9—C12	166.77 (10)	C17—Si2—C21—C24	43.22 (12)
Si2—Si1—C9—C12	44.48 (11)	C13—Si2—C21—C24	−71.21 (12)
C1—Si1—C9—C11	161.60 (10)	Si1—Si2—C21—C24	166.06 (10)
C5—Si1—C9—C11	47.06 (12)

(II) 1,1,2,2-Tetra-tert-butyl-1,2-diphenyldisilane

Crystal data

C28H46Si2	Z = 4
Mr = 438.83	F(000) = 968
Triclinic, P1	Dx = 1.089 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 9.0240 (11) Å	Cell parameters from 165 reflections
b = 17.566 (2) Å	θ = 3–26°
c = 18.961 (3) Å	µ = 0.15 mm^−1
α = 116.476 (6)°	T = 157 K
β = 95.018 (7)°	Block, colorless
γ = 90.263 (10)°	0.30 × 0.26 × 0.25 mm
V = 2676.8 (6) Å^3

Data collection

Siemens SMART 1K CCD diffractometer	12352 independent reflections
Radiation source: normal-focus sealed tube	7513 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
ω scans	θmax = 28.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −11→11
Tmin = 0.873, Tmax = 0.964	k = −23→23
31180 measured reflections	l = −25→25

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.051P)^2] where P = (Fo^2 + 2Fc^2)/3
12352 reflections	(Δ/σ)max = 0.001
565 parameters	Δρmax = 0.33 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

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	0.40260 (6)	0.21134 (3)	0.83084 (3)	0.02539 (14)
Si2	0.47108 (6)	0.21499 (3)	0.70812 (3)	0.02498 (14)
Si3	1.09848 (6)	0.27363 (3)	0.32339 (3)	0.02468 (14)
Si4	0.98576 (6)	0.30935 (3)	0.21761 (3)	0.02642 (14)
C1	0.3063 (2)	0.31601 (12)	0.88451 (11)	0.0272 (5)
C2	0.1696 (2)	0.32745 (13)	0.85030 (12)	0.0317 (5)
H2	0.1244	0.2814	0.8035	0.038*
C3	0.0976 (2)	0.40332 (14)	0.88205 (13)	0.0395 (6)
H3	0.0056	0.4088	0.8566	0.047*
C4	0.1599 (3)	0.47119 (14)	0.95088 (14)	0.0421 (6)
H4	0.1127	0.5239	0.9724	0.051*
C5	0.2910 (3)	0.46087 (14)	0.98744 (13)	0.0409 (6)
H5	0.3332	0.5064	1.0355	0.049*
C6	0.3627 (2)	0.38501 (13)	0.95518 (12)	0.0325 (5)
H6	0.4531	0.3797	0.9820	0.039*
C7	0.5738 (2)	0.20840 (13)	0.89947 (12)	0.0328 (5)
C8	0.5272 (3)	0.22161 (15)	0.98063 (12)	0.0441 (6)
H8A	0.6154	0.2209	1.0144	0.066*
H8B	0.4557	0.1757	0.9728	0.066*
H8C	0.4811	0.2765	1.0061	0.066*
C9	0.6912 (2)	0.27865 (14)	0.91287 (13)	0.0414 (6)
H9A	0.7700	0.2821	0.9533	0.062*
H9B	0.6439	0.3334	0.9307	0.062*
H9C	0.7342	0.2652	0.8632	0.062*
C10	0.6553 (3)	0.12405 (14)	0.86656 (13)	0.0427 (6)
H10A	0.7530	0.1326	0.8967	0.064*
H10B	0.6684	0.1061	0.8107	0.064*
H10C	0.5961	0.0800	0.8714	0.064*
C11	0.2503 (2)	0.12310 (13)	0.81337 (12)	0.0326 (5)
C12	0.1494 (3)	0.15552 (15)	0.88080 (14)	0.0474 (6)
H12A	0.0823	0.1087	0.8752	0.071*
H12B	0.0907	0.2013	0.8786	0.071*
H12C	0.2108	0.1773	0.9317	0.071*
C13	0.1507 (3)	0.09454 (14)	0.73465 (13)	0.0428 (6)
H13A	0.0707	0.0550	0.7316	0.064*
H13B	0.2108	0.0661	0.6902	0.064*
H13C	0.1074	0.1444	0.7321	0.064*
C14	0.3180 (3)	0.04165 (13)	0.81117 (14)	0.0463 (6)
H14A	0.2382	−0.0016	0.7993	0.069*
H14B	0.3721	0.0549	0.8627	0.069*
H14C	0.3869	0.0199	0.7701	0.069*
C15	0.2882 (2)	0.19813 (12)	0.64157 (11)	0.0275 (5)
C16	0.2425 (2)	0.12230 (13)	0.57392 (12)	0.0336 (5)
H16	0.3035	0.0748	0.5601	0.040*
C17	0.1115 (3)	0.11409 (15)	0.52636 (13)	0.0395 (6)
H17	0.0838	0.0614	0.4814	0.047*
C18	0.0222 (2)	0.18165 (15)	0.54406 (13)	0.0395 (6)
H18	−0.0667	0.1764	0.5111	0.047*
C19	0.0620 (2)	0.25712 (14)	0.60982 (13)	0.0363 (5)
H19	0.0002	0.3042	0.6224	0.044*
C20	0.1924 (2)	0.26516 (13)	0.65815 (12)	0.0313 (5)
H20	0.2171	0.3177	0.7038	0.038*
C21	0.6013 (2)	0.12466 (13)	0.64978 (12)	0.0308 (5)
C22	0.5377 (3)	0.03894 (13)	0.64132 (12)	0.0371 (5)
H22A	0.5958	−0.0074	0.6064	0.056*
H22B	0.4336	0.0299	0.6186	0.056*
H22C	0.5433	0.0399	0.6935	0.056*
C23	0.7628 (2)	0.13488 (14)	0.68858 (13)	0.0403 (6)
H23A	0.8105	0.0803	0.6643	0.060*
H23B	0.7616	0.1529	0.7454	0.060*
H23C	0.8187	0.1779	0.6806	0.060*
C24	0.6153 (3)	0.11856 (14)	0.56669 (12)	0.0414 (6)
H24A	0.6778	0.0714	0.5376	0.062*
H24B	0.6608	0.1720	0.5722	0.062*
H24C	0.5162	0.1085	0.5376	0.062*
C25	0.5534 (2)	0.32644 (13)	0.72476 (12)	0.0305 (5)
C26	0.4964 (2)	0.40077 (12)	0.79587 (12)	0.0372 (5)
H26A	0.5338	0.4547	0.7988	0.056*
H26B	0.5317	0.3971	0.8446	0.056*
H26C	0.3873	0.3981	0.7897	0.056*
C27	0.7245 (2)	0.33340 (15)	0.73911 (15)	0.0496 (7)
H27A	0.7600	0.3916	0.7529	0.074*
H27B	0.7663	0.2935	0.6909	0.074*
H27C	0.7561	0.3196	0.7827	0.074*
C28	0.5140 (3)	0.34103 (14)	0.65083 (12)	0.0420 (6)
H28A	0.5652	0.3937	0.6581	0.063*
H28B	0.4061	0.3457	0.6435	0.063*
H28C	0.5456	0.2930	0.6040	0.063*
C29	0.9328 (2)	0.26410 (12)	0.37612 (11)	0.0251 (4)
C30	0.8354 (2)	0.19223 (13)	0.33837 (11)	0.0291 (5)
H30	0.8535	0.1503	0.2872	0.035*
C31	0.7137 (2)	0.17930 (14)	0.37208 (12)	0.0332 (5)
H31	0.6518	0.1288	0.3446	0.040*
C32	0.6825 (2)	0.23985 (14)	0.44557 (12)	0.0342 (5)
H32	0.5983	0.2319	0.4688	0.041*
C33	0.7748 (2)	0.31192 (14)	0.48487 (12)	0.0353 (5)
H33	0.7536	0.3542	0.5353	0.042*
C34	0.8987 (2)	0.32337 (13)	0.45148 (12)	0.0310 (5)
H34	0.9624	0.3729	0.4805	0.037*
C35	1.2398 (2)	0.36089 (13)	0.40154 (12)	0.0338 (5)
C36	1.2779 (3)	0.34527 (14)	0.47485 (12)	0.0455 (6)
H36A	1.3436	0.3923	0.5144	0.068*
H36B	1.3283	0.2916	0.4592	0.068*
H36C	1.1860	0.3420	0.4975	0.068*
C37	1.1728 (2)	0.44891 (13)	0.42790 (13)	0.0391 (6)
H37A	1.2391	0.4922	0.4711	0.059*
H37B	1.0750	0.4477	0.4462	0.059*
H37C	1.1619	0.4628	0.3831	0.059*
C38	1.3904 (2)	0.36823 (15)	0.37169 (14)	0.0484 (6)
H38A	1.4421	0.4228	0.4080	0.073*
H38B	1.3730	0.3651	0.3187	0.073*
H38C	1.4519	0.3215	0.3694	0.073*
C39	1.1830 (2)	0.16089 (12)	0.28358 (12)	0.0299 (5)
C40	1.1651 (3)	0.12264 (14)	0.34199 (13)	0.0418 (6)
H40A	1.2189	0.0700	0.3254	0.063*
H40B	1.0593	0.1101	0.3422	0.063*
H40C	1.2058	0.1636	0.3954	0.063*
C41	1.1103 (2)	0.09643 (12)	0.20167 (12)	0.0357 (5)
H41A	1.1469	0.0398	0.1890	0.053*
H41B	1.1359	0.1137	0.1615	0.053*
H41C	1.0019	0.0948	0.2024	0.053*
C42	1.3507 (2)	0.16282 (15)	0.27521 (14)	0.0455 (6)
H42A	1.3830	0.1044	0.2482	0.068*
H42B	1.4057	0.1920	0.3279	0.068*
H42C	1.3703	0.1933	0.2442	0.068*
C43	0.8722 (2)	0.20731 (12)	0.14458 (11)	0.0278 (5)
C44	0.9149 (3)	0.14953 (13)	0.07113 (12)	0.0352 (5)
H44	1.0032	0.1622	0.0538	0.042*
C45	0.8329 (3)	0.07415 (14)	0.02248 (12)	0.0400 (6)
H45	0.8672	0.0360	−0.0264	0.048*
C46	0.7024 (3)	0.05449 (14)	0.04462 (14)	0.0436 (6)
H46	0.6466	0.0029	0.0116	0.052*
C47	0.6542 (3)	0.11096 (14)	0.11563 (13)	0.0394 (6)
H47	0.5632	0.0988	0.1311	0.047*
C48	0.7374 (2)	0.18521 (13)	0.16448 (12)	0.0317 (5)
H48	0.7021	0.2227	0.2133	0.038*
C49	1.1329 (3)	0.33361 (14)	0.16055 (13)	0.0394 (6)
C50	1.2526 (3)	0.26657 (15)	0.13856 (14)	0.0467 (6)
H50A	1.3185	0.2754	0.1042	0.070*
H50B	1.2042	0.2094	0.1107	0.070*
H50C	1.3110	0.2723	0.1869	0.070*
C51	1.2196 (3)	0.42041 (15)	0.20862 (15)	0.0602 (8)
H51A	1.3059	0.4228	0.1816	0.090*
H51B	1.2534	0.4270	0.2617	0.090*
H51C	1.1543	0.4664	0.2130	0.090*
C52	1.0594 (3)	0.33549 (16)	0.08456 (14)	0.0545 (7)
H52A	1.1366	0.3444	0.0554	0.082*
H52B	0.9909	0.3820	0.0990	0.082*
H52C	1.0042	0.2812	0.0512	0.082*
C53	0.8392 (2)	0.39848 (13)	0.25250 (12)	0.0332 (5)
C54	0.7624 (2)	0.40245 (14)	0.32286 (13)	0.0398 (6)
H54A	0.6838	0.4434	0.3345	0.060*
H54B	0.8357	0.4205	0.3693	0.060*
H54C	0.7187	0.3460	0.3098	0.060*
C55	0.9048 (3)	0.48959 (13)	0.27858 (14)	0.0490 (6)
H55A	0.8292	0.5308	0.3025	0.074*
H55B	0.9351	0.4945	0.2324	0.074*
H55C	0.9915	0.5012	0.3174	0.074*
C56	0.7172 (3)	0.38147 (14)	0.18397 (13)	0.0447 (6)
H56A	0.6510	0.4292	0.1999	0.067*
H56B	0.6595	0.3289	0.1714	0.067*
H56C	0.7639	0.3756	0.1372	0.067*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0280 (3)	0.0240 (3)	0.0237 (3)	0.0013 (2)	0.0014 (2)	0.0105 (2)
Si2	0.0252 (3)	0.0255 (3)	0.0241 (3)	0.0043 (2)	0.0014 (2)	0.0112 (3)
Si3	0.0225 (3)	0.0245 (3)	0.0239 (3)	0.0045 (2)	0.0048 (2)	0.0076 (2)
Si4	0.0292 (3)	0.0248 (3)	0.0268 (3)	0.0037 (2)	0.0072 (3)	0.0122 (3)
C1	0.0271 (12)	0.0286 (11)	0.0265 (11)	−0.0005 (9)	0.0048 (9)	0.0127 (9)
C2	0.0316 (13)	0.0310 (12)	0.0288 (11)	0.0016 (10)	0.0055 (10)	0.0097 (10)
C3	0.0312 (13)	0.0414 (14)	0.0460 (14)	0.0073 (11)	0.0074 (11)	0.0191 (12)
C4	0.0438 (15)	0.0304 (13)	0.0509 (15)	0.0107 (11)	0.0183 (12)	0.0145 (12)
C5	0.0460 (15)	0.0321 (13)	0.0354 (13)	−0.0003 (11)	0.0069 (11)	0.0065 (11)
C6	0.0344 (13)	0.0303 (12)	0.0301 (12)	0.0005 (10)	0.0016 (10)	0.0114 (10)
C7	0.0352 (13)	0.0335 (12)	0.0276 (11)	0.0066 (10)	0.0015 (10)	0.0122 (10)
C8	0.0527 (16)	0.0494 (15)	0.0318 (13)	0.0075 (12)	−0.0009 (11)	0.0205 (12)
C9	0.0343 (14)	0.0474 (15)	0.0381 (13)	0.0023 (11)	−0.0061 (11)	0.0169 (12)
C10	0.0480 (15)	0.0452 (14)	0.0372 (13)	0.0116 (12)	−0.0011 (11)	0.0215 (12)
C11	0.0352 (13)	0.0291 (12)	0.0356 (12)	−0.0034 (10)	0.0040 (10)	0.0165 (10)
C12	0.0492 (16)	0.0443 (15)	0.0547 (16)	−0.0050 (12)	0.0159 (13)	0.0255 (13)
C13	0.0383 (14)	0.0371 (13)	0.0485 (15)	−0.0138 (11)	−0.0044 (11)	0.0170 (12)
C14	0.0583 (17)	0.0299 (13)	0.0550 (15)	−0.0034 (11)	0.0048 (13)	0.0231 (12)
C15	0.0289 (12)	0.0303 (12)	0.0251 (11)	0.0034 (9)	0.0011 (9)	0.0142 (10)
C16	0.0376 (13)	0.0296 (12)	0.0306 (12)	0.0066 (10)	−0.0029 (10)	0.0120 (10)
C17	0.0403 (14)	0.0409 (14)	0.0318 (12)	−0.0020 (11)	−0.0071 (11)	0.0134 (11)
C18	0.0273 (13)	0.0563 (16)	0.0382 (13)	−0.0009 (11)	−0.0057 (10)	0.0256 (12)
C19	0.0285 (13)	0.0446 (14)	0.0430 (14)	0.0130 (11)	0.0067 (11)	0.0253 (12)
C20	0.0313 (13)	0.0333 (12)	0.0293 (11)	0.0051 (10)	0.0040 (10)	0.0138 (10)
C21	0.0307 (12)	0.0309 (12)	0.0279 (11)	0.0085 (10)	0.0027 (9)	0.0105 (10)
C22	0.0429 (14)	0.0317 (12)	0.0343 (12)	0.0122 (10)	0.0030 (10)	0.0127 (10)
C23	0.0317 (13)	0.0442 (14)	0.0427 (14)	0.0126 (11)	0.0060 (11)	0.0170 (12)
C24	0.0436 (15)	0.0431 (14)	0.0345 (13)	0.0138 (11)	0.0111 (11)	0.0134 (11)
C25	0.0298 (12)	0.0287 (12)	0.0354 (12)	−0.0001 (9)	0.0047 (10)	0.0163 (10)
C26	0.0423 (14)	0.0275 (12)	0.0389 (13)	−0.0058 (10)	0.0036 (11)	0.0124 (10)
C27	0.0372 (15)	0.0415 (14)	0.0751 (18)	−0.0055 (11)	0.0040 (13)	0.0307 (14)
C28	0.0497 (16)	0.0397 (14)	0.0447 (14)	0.0056 (11)	0.0157 (12)	0.0241 (12)
C29	0.0245 (11)	0.0278 (11)	0.0265 (11)	0.0092 (9)	0.0048 (9)	0.0148 (9)
C30	0.0297 (12)	0.0332 (12)	0.0245 (11)	0.0081 (10)	0.0037 (9)	0.0127 (10)
C31	0.0260 (12)	0.0398 (13)	0.0369 (13)	0.0001 (10)	0.0012 (10)	0.0203 (11)
C32	0.0260 (12)	0.0497 (14)	0.0366 (13)	0.0081 (11)	0.0087 (10)	0.0269 (12)
C33	0.0387 (14)	0.0400 (13)	0.0305 (12)	0.0146 (11)	0.0129 (10)	0.0171 (11)
C34	0.0323 (13)	0.0298 (12)	0.0300 (12)	0.0058 (10)	0.0073 (10)	0.0119 (10)
C35	0.0290 (12)	0.0318 (12)	0.0322 (12)	−0.0011 (10)	0.0030 (10)	0.0067 (10)
C36	0.0416 (15)	0.0456 (15)	0.0350 (13)	0.0008 (12)	−0.0093 (11)	0.0076 (11)
C37	0.0381 (14)	0.0284 (12)	0.0395 (13)	−0.0039 (10)	0.0045 (11)	0.0050 (10)
C38	0.0318 (14)	0.0479 (15)	0.0495 (15)	−0.0061 (11)	0.0050 (12)	0.0073 (12)
C39	0.0270 (12)	0.0291 (12)	0.0301 (12)	0.0086 (9)	0.0030 (9)	0.0099 (10)
C40	0.0479 (15)	0.0381 (13)	0.0408 (14)	0.0160 (11)	0.0002 (11)	0.0194 (11)
C41	0.0422 (14)	0.0245 (11)	0.0360 (12)	0.0098 (10)	0.0066 (11)	0.0092 (10)
C42	0.0309 (14)	0.0443 (15)	0.0517 (15)	0.0148 (11)	0.0077 (11)	0.0123 (12)
C43	0.0325 (12)	0.0282 (11)	0.0253 (11)	0.0058 (9)	0.0002 (9)	0.0148 (9)
C44	0.0393 (14)	0.0357 (13)	0.0310 (12)	0.0064 (10)	0.0031 (10)	0.0153 (10)
C45	0.0518 (16)	0.0351 (13)	0.0263 (12)	0.0101 (11)	−0.0015 (11)	0.0087 (10)
C46	0.0519 (16)	0.0323 (13)	0.0431 (14)	−0.0039 (12)	−0.0105 (12)	0.0167 (12)
C47	0.0399 (14)	0.0383 (13)	0.0453 (14)	−0.0054 (11)	−0.0024 (11)	0.0247 (12)
C48	0.0363 (13)	0.0314 (12)	0.0315 (12)	0.0050 (10)	0.0023 (10)	0.0180 (10)
C49	0.0431 (15)	0.0394 (13)	0.0423 (14)	−0.0002 (11)	0.0136 (11)	0.0225 (11)
C50	0.0392 (15)	0.0562 (16)	0.0448 (14)	0.0000 (12)	0.0177 (12)	0.0203 (13)
C51	0.0635 (19)	0.0490 (16)	0.0722 (19)	−0.0130 (14)	0.0216 (15)	0.0285 (15)
C52	0.0659 (19)	0.0632 (17)	0.0527 (16)	0.0070 (14)	0.0207 (14)	0.0396 (14)
C53	0.0366 (13)	0.0282 (12)	0.0355 (12)	0.0100 (10)	0.0047 (10)	0.0147 (10)
C54	0.0412 (14)	0.0367 (13)	0.0419 (14)	0.0189 (11)	0.0129 (11)	0.0162 (11)
C55	0.0593 (17)	0.0307 (13)	0.0570 (16)	0.0059 (12)	0.0065 (13)	0.0196 (12)
C56	0.0491 (16)	0.0412 (14)	0.0491 (15)	0.0155 (12)	0.0030 (12)	0.0252 (12)

Geometric parameters (Å, º)

Si1—C1	1.916 (2)	C26—H26C	0.9800
Si1—C7	1.947 (2)	C27—H27A	0.9800
Si1—C11	1.961 (2)	C27—H27B	0.9800
Si1—Si2	2.4869 (8)	C27—H27C	0.9800
Si2—C15	1.924 (2)	C28—H28A	0.9800
Si2—C21	1.950 (2)	C28—H28B	0.9800
Si2—C25	1.969 (2)	C28—H28C	0.9800
Si3—C29	1.916 (2)	C29—C30	1.398 (3)
Si3—C35	1.949 (2)	C29—C34	1.405 (3)
Si3—C39	1.963 (2)	C30—C31	1.384 (3)
Si3—Si4	2.4944 (8)	C30—H30	0.9500
Si4—C43	1.924 (2)	C31—C32	1.379 (3)
Si4—C49	1.942 (2)	C31—H31	0.9500
Si4—C53	1.971 (2)	C32—C33	1.376 (3)
C1—C6	1.397 (3)	C32—H32	0.9500
C1—C2	1.400 (3)	C33—C34	1.388 (3)
C2—C3	1.386 (3)	C33—H33	0.9500
C2—H2	0.9500	C34—H34	0.9500
C3—C4	1.385 (3)	C35—C37	1.542 (3)
C3—H3	0.9500	C35—C38	1.543 (3)
C4—C5	1.372 (3)	C35—C36	1.544 (3)
C4—H4	0.9500	C36—H36A	0.9800
C5—C6	1.385 (3)	C36—H36B	0.9800
C5—H5	0.9500	C36—H36C	0.9800
C6—H6	0.9500	C37—H37A	0.9800
C7—C9	1.539 (3)	C37—H37B	0.9800
C7—C10	1.546 (3)	C37—H37C	0.9800
C7—C8	1.548 (3)	C38—H38A	0.9800
C8—H8A	0.9800	C38—H38B	0.9800
C8—H8B	0.9800	C38—H38C	0.9800
C8—H8C	0.9800	C39—C42	1.538 (3)
C9—H9A	0.9800	C39—C41	1.540 (3)
C9—H9B	0.9800	C39—C40	1.549 (3)
C9—H9C	0.9800	C40—H40A	0.9800
C10—H10A	0.9800	C40—H40B	0.9800
C10—H10B	0.9800	C40—H40C	0.9800
C10—H10C	0.9800	C41—H41A	0.9800
C11—C12	1.532 (3)	C41—H41B	0.9800
C11—C13	1.543 (3)	C41—H41C	0.9800
C11—C14	1.543 (3)	C42—H42A	0.9800
C12—H12A	0.9800	C42—H42B	0.9800
C12—H12B	0.9800	C42—H42C	0.9800
C12—H12C	0.9800	C43—C44	1.398 (3)
C13—H13A	0.9800	C43—C48	1.407 (3)
C13—H13B	0.9800	C44—C45	1.391 (3)
C13—H13C	0.9800	C44—H44	0.9500
C14—H14A	0.9800	C45—C46	1.376 (3)
C14—H14B	0.9800	C45—H45	0.9500
C14—H14C	0.9800	C46—C47	1.379 (3)
C15—C20	1.400 (3)	C46—H46	0.9500
C15—C16	1.403 (3)	C47—C48	1.384 (3)
C16—C17	1.388 (3)	C47—H47	0.9500
C16—H16	0.9500	C48—H48	0.9500
C17—C18	1.368 (3)	C49—C50	1.542 (3)
C17—H17	0.9500	C49—C51	1.547 (3)
C18—C19	1.373 (3)	C49—C52	1.547 (3)
C18—H18	0.9500	C50—H50A	0.9800
C19—C20	1.392 (3)	C50—H50B	0.9800
C19—H19	0.9500	C50—H50C	0.9800
C20—H20	0.9500	C51—H51A	0.9800
C21—C22	1.544 (3)	C51—H51B	0.9800
C21—C23	1.546 (3)	C51—H51C	0.9800
C21—C24	1.547 (3)	C52—H52A	0.9800
C22—H22A	0.9800	C52—H52B	0.9800
C22—H22B	0.9800	C52—H52C	0.9800
C22—H22C	0.9800	C53—C54	1.531 (3)
C23—H23A	0.9800	C53—C56	1.546 (3)
C23—H23B	0.9800	C53—C55	1.546 (3)
C23—H23C	0.9800	C54—H54A	0.9800
C24—H24A	0.9800	C54—H54B	0.9800
C24—H24B	0.9800	C54—H54C	0.9800
C24—H24C	0.9800	C55—H55A	0.9800
C25—C26	1.531 (3)	C55—H55B	0.9800
C25—C27	1.539 (3)	C55—H55C	0.9800
C25—C28	1.546 (3)	C56—H56A	0.9800
C26—H26A	0.9800	C56—H56B	0.9800
C26—H26B	0.9800	C56—H56C	0.9800
C1—Si1—C7	108.90 (9)	C25—C27—H27A	109.5
C1—Si1—C11	104.10 (9)	C25—C27—H27B	109.5
C7—Si1—C11	111.05 (9)	H27A—C27—H27B	109.5
C1—Si1—Si2	103.91 (6)	C25—C27—H27C	109.5
C7—Si1—Si2	113.40 (7)	H27A—C27—H27C	109.5
C11—Si1—Si2	114.65 (7)	H27B—C27—H27C	109.5
C15—Si2—C21	107.90 (9)	C25—C28—H28A	109.5
C15—Si2—C25	104.01 (9)	C25—C28—H28B	109.5
C21—Si2—C25	110.74 (9)	H28A—C28—H28B	109.5
C15—Si2—Si1	106.51 (6)	C25—C28—H28C	109.5
C21—Si2—Si1	112.90 (7)	H28A—C28—H28C	109.5
C25—Si2—Si1	114.11 (6)	H28B—C28—H28C	109.5
C29—Si3—C35	108.11 (9)	C30—C29—C34	115.21 (18)
C29—Si3—C39	104.08 (9)	C30—C29—Si3	118.89 (14)
C35—Si3—C39	110.91 (9)	C34—C29—Si3	125.90 (15)
C29—Si3—Si4	104.41 (6)	C31—C30—C29	123.06 (19)
C35—Si3—Si4	114.20 (7)	C31—C30—H30	118.5
C39—Si3—Si4	114.21 (6)	C29—C30—H30	118.5
C43—Si4—C49	107.94 (9)	C32—C31—C30	119.9 (2)
C43—Si4—C53	104.91 (9)	C32—C31—H31	120.1
C49—Si4—C53	111.19 (9)	C30—C31—H31	120.1
C43—Si4—Si3	104.13 (6)	C33—C32—C31	119.16 (19)
C49—Si4—Si3	113.16 (8)	C33—C32—H32	120.4
C53—Si4—Si3	114.68 (7)	C31—C32—H32	120.4
C6—C1—C2	115.55 (19)	C32—C33—C34	120.6 (2)
C6—C1—Si1	125.60 (16)	C32—C33—H33	119.7
C2—C1—Si1	118.82 (15)	C34—C33—H33	119.7
C3—C2—C1	122.6 (2)	C33—C34—C29	122.1 (2)
C3—C2—H2	118.7	C33—C34—H34	119.0
C1—C2—H2	118.7	C29—C34—H34	119.0
C4—C3—C2	119.9 (2)	C37—C35—C38	105.66 (17)
C4—C3—H3	120.0	C37—C35—C36	109.10 (17)
C2—C3—H3	120.0	C38—C35—C36	105.85 (19)
C5—C4—C3	118.8 (2)	C37—C35—Si3	109.32 (14)
C5—C4—H4	120.6	C38—C35—Si3	114.99 (14)
C3—C4—H4	120.6	C36—C35—Si3	111.62 (14)
C4—C5—C6	120.9 (2)	C35—C36—H36A	109.5
C4—C5—H5	119.5	C35—C36—H36B	109.5
C6—C5—H5	119.5	H36A—C36—H36B	109.5
C5—C6—C1	122.1 (2)	C35—C36—H36C	109.5
C5—C6—H6	119.0	H36A—C36—H36C	109.5
C1—C6—H6	119.0	H36B—C36—H36C	109.5
C9—C7—C10	105.93 (18)	C35—C37—H37A	109.5
C9—C7—C8	108.92 (17)	C35—C37—H37B	109.5
C10—C7—C8	105.95 (17)	H37A—C37—H37B	109.5
C9—C7—Si1	110.09 (14)	C35—C37—H37C	109.5
C10—C7—Si1	114.67 (14)	H37A—C37—H37C	109.5
C8—C7—Si1	110.99 (15)	H37B—C37—H37C	109.5
C7—C8—H8A	109.5	C35—C38—H38A	109.5
C7—C8—H8B	109.5	C35—C38—H38B	109.5
H8A—C8—H8B	109.5	H38A—C38—H38B	109.5
C7—C8—H8C	109.5	C35—C38—H38C	109.5
H8A—C8—H8C	109.5	H38A—C38—H38C	109.5
H8B—C8—H8C	109.5	H38B—C38—H38C	109.5
C7—C9—H9A	109.5	C42—C39—C41	105.59 (17)
C7—C9—H9B	109.5	C42—C39—C40	105.87 (17)
H9A—C9—H9B	109.5	C41—C39—C40	107.60 (17)
C7—C9—H9C	109.5	C42—C39—Si3	113.47 (14)
H9A—C9—H9C	109.5	C41—C39—Si3	113.83 (14)
H9B—C9—H9C	109.5	C40—C39—Si3	110.00 (14)
C7—C10—H10A	109.5	C39—C40—H40A	109.5
C7—C10—H10B	109.5	C39—C40—H40B	109.5
H10A—C10—H10B	109.5	H40A—C40—H40B	109.5
C7—C10—H10C	109.5	C39—C40—H40C	109.5
H10A—C10—H10C	109.5	H40A—C40—H40C	109.5
H10B—C10—H10C	109.5	H40B—C40—H40C	109.5
C12—C11—C13	107.98 (19)	C39—C41—H41A	109.5
C12—C11—C14	106.66 (17)	C39—C41—H41B	109.5
C13—C11—C14	106.06 (17)	H41A—C41—H41B	109.5
C12—C11—Si1	110.19 (14)	C39—C41—H41C	109.5
C13—C11—Si1	113.09 (14)	H41A—C41—H41C	109.5
C14—C11—Si1	112.52 (15)	H41B—C41—H41C	109.5
C11—C12—H12A	109.5	C39—C42—H42A	109.5
C11—C12—H12B	109.5	C39—C42—H42B	109.5
H12A—C12—H12B	109.5	H42A—C42—H42B	109.5
C11—C12—H12C	109.5	C39—C42—H42C	109.5
H12A—C12—H12C	109.5	H42A—C42—H42C	109.5
H12B—C12—H12C	109.5	H42B—C42—H42C	109.5
C11—C13—H13A	109.5	C44—C43—C48	115.17 (19)
C11—C13—H13B	109.5	C44—C43—Si4	124.74 (16)
H13A—C13—H13B	109.5	C48—C43—Si4	120.07 (15)
C11—C13—H13C	109.5	C45—C44—C43	122.4 (2)
H13A—C13—H13C	109.5	C45—C44—H44	118.8
H13B—C13—H13C	109.5	C43—C44—H44	118.8
C11—C14—H14A	109.5	C46—C45—C44	120.5 (2)
C11—C14—H14B	109.5	C46—C45—H45	119.8
H14A—C14—H14B	109.5	C44—C45—H45	119.8
C11—C14—H14C	109.5	C45—C46—C47	118.9 (2)
H14A—C14—H14C	109.5	C45—C46—H46	120.6
H14B—C14—H14C	109.5	C47—C46—H46	120.6
C20—C15—C16	115.44 (19)	C46—C47—C48	120.5 (2)
C20—C15—Si2	119.92 (15)	C46—C47—H47	119.8
C16—C15—Si2	124.62 (15)	C48—C47—H47	119.8
C17—C16—C15	122.5 (2)	C47—C48—C43	122.5 (2)
C17—C16—H16	118.8	C47—C48—H48	118.7
C15—C16—H16	118.8	C43—C48—H48	118.7
C18—C17—C16	120.2 (2)	C50—C49—C51	105.3 (2)
C18—C17—H17	119.9	C50—C49—C52	109.51 (19)
C16—C17—H17	119.9	C51—C49—C52	106.00 (19)
C17—C18—C19	119.5 (2)	C50—C49—Si4	110.51 (14)
C17—C18—H18	120.3	C51—C49—Si4	114.00 (15)
C19—C18—H18	120.3	C52—C49—Si4	111.22 (16)
C18—C19—C20	120.4 (2)	C49—C50—H50A	109.5
C18—C19—H19	119.8	C49—C50—H50B	109.5
C20—C19—H19	119.8	H50A—C50—H50B	109.5
C19—C20—C15	122.0 (2)	C49—C50—H50C	109.5
C19—C20—H20	119.0	H50A—C50—H50C	109.5
C15—C20—H20	119.0	H50B—C50—H50C	109.5
C22—C21—C23	105.81 (17)	C49—C51—H51A	109.5
C22—C21—C24	109.58 (17)	C49—C51—H51B	109.5
C23—C21—C24	105.50 (17)	H51A—C51—H51B	109.5
C22—C21—Si2	109.43 (14)	C49—C51—H51C	109.5
C23—C21—Si2	115.51 (14)	H51A—C51—H51C	109.5
C24—C21—Si2	110.77 (14)	H51B—C51—H51C	109.5
C21—C22—H22A	109.5	C49—C52—H52A	109.5
C21—C22—H22B	109.5	C49—C52—H52B	109.5
H22A—C22—H22B	109.5	H52A—C52—H52B	109.5
C21—C22—H22C	109.5	C49—C52—H52C	109.5
H22A—C22—H22C	109.5	H52A—C52—H52C	109.5
H22B—C22—H22C	109.5	H52B—C52—H52C	109.5
C21—C23—H23A	109.5	C54—C53—C56	107.82 (18)
C21—C23—H23B	109.5	C54—C53—C55	105.69 (17)
H23A—C23—H23B	109.5	C56—C53—C55	105.91 (17)
C21—C23—H23C	109.5	C54—C53—Si4	112.52 (13)
H23A—C23—H23C	109.5	C56—C53—Si4	110.01 (14)
H23B—C23—H23C	109.5	C55—C53—Si4	114.46 (16)
C21—C24—H24A	109.5	C53—C54—H54A	109.5
C21—C24—H24B	109.5	C53—C54—H54B	109.5
H24A—C24—H24B	109.5	H54A—C54—H54B	109.5
C21—C24—H24C	109.5	C53—C54—H54C	109.5
H24A—C24—H24C	109.5	H54A—C54—H54C	109.5
H24B—C24—H24C	109.5	H54B—C54—H54C	109.5
C26—C25—C27	106.72 (18)	C53—C55—H55A	109.5
C26—C25—C28	107.93 (17)	C53—C55—H55B	109.5
C27—C25—C28	106.05 (17)	H55A—C55—H55B	109.5
C26—C25—Si2	112.75 (13)	C53—C55—H55C	109.5
C27—C25—Si2	112.15 (14)	H55A—C55—H55C	109.5
C28—C25—Si2	110.89 (14)	H55B—C55—H55C	109.5
C25—C26—H26A	109.5	C53—C56—H56A	109.5
C25—C26—H26B	109.5	C53—C56—H56B	109.5
H26A—C26—H26B	109.5	H56A—C56—H56B	109.5
C25—C26—H26C	109.5	C53—C56—H56C	109.5
H26A—C26—H26C	109.5	H56A—C56—H56C	109.5
H26B—C26—H26C	109.5	H56B—C56—H56C	109.5
C1—Si1—Si2—C15	−71.47 (9)	C15—Si2—C25—C26	87.92 (16)
C7—Si1—Si2—C15	170.44 (9)	C21—Si2—C25—C26	−156.42 (14)
C11—Si1—Si2—C15	41.46 (10)	Si1—Si2—C25—C26	−27.71 (17)
C1—Si1—Si2—C21	170.29 (9)	C15—Si2—C25—C27	−151.59 (15)
C7—Si1—Si2—C21	52.20 (10)	C21—Si2—C25—C27	−35.92 (18)
C11—Si1—Si2—C21	−76.78 (10)	Si1—Si2—C25—C27	92.78 (15)
C1—Si1—Si2—C25	42.68 (10)	C15—Si2—C25—C28	−33.23 (17)
C7—Si1—Si2—C25	−75.40 (10)	C21—Si2—C25—C28	82.43 (16)
C11—Si1—Si2—C25	155.62 (10)	Si1—Si2—C25—C28	−148.86 (13)
C29—Si3—Si4—C43	−68.61 (9)	C35—Si3—C29—C30	−163.88 (15)
C35—Si3—Si4—C43	173.53 (9)	C39—Si3—C29—C30	−45.90 (17)
C39—Si3—Si4—C43	44.40 (10)	Si4—Si3—C29—C30	74.16 (15)
C29—Si3—Si4—C49	174.44 (9)	C35—Si3—C29—C34	15.5 (2)
C35—Si3—Si4—C49	56.58 (10)	C39—Si3—C29—C34	133.51 (17)
C39—Si3—Si4—C49	−72.56 (10)	Si4—Si3—C29—C34	−106.43 (17)
C29—Si3—Si4—C53	45.46 (10)	C34—C29—C30—C31	−0.2 (3)
C35—Si3—Si4—C53	−72.41 (10)	Si3—C29—C30—C31	179.31 (15)
C39—Si3—Si4—C53	158.46 (10)	C29—C30—C31—C32	1.4 (3)
C7—Si1—C1—C6	9.90 (19)	C30—C31—C32—C33	−1.0 (3)
C11—Si1—C1—C6	128.42 (17)	C31—C32—C33—C34	−0.6 (3)
Si2—Si1—C1—C6	−111.24 (16)	C32—C33—C34—C29	1.9 (3)
C7—Si1—C1—C2	−172.21 (15)	C30—C29—C34—C33	−1.5 (3)
C11—Si1—C1—C2	−53.69 (17)	Si3—C29—C34—C33	179.11 (16)
Si2—Si1—C1—C2	66.65 (16)	C29—Si3—C35—C37	−69.57 (16)
C6—C1—C2—C3	2.9 (3)	C39—Si3—C35—C37	176.92 (13)
Si1—C1—C2—C3	−175.23 (16)	Si4—Si3—C35—C37	46.15 (15)
C1—C2—C3—C4	−0.9 (3)	C29—Si3—C35—C38	171.80 (16)
C2—C3—C4—C5	−1.6 (3)	C39—Si3—C35—C38	58.29 (19)
C3—C4—C5—C6	1.9 (3)	Si4—Si3—C35—C38	−72.47 (17)
C4—C5—C6—C1	0.2 (3)	C29—Si3—C35—C36	51.21 (17)
C2—C1—C6—C5	−2.5 (3)	C39—Si3—C35—C36	−62.30 (17)
Si1—C1—C6—C5	175.42 (16)	Si4—Si3—C35—C36	166.94 (13)
C1—Si1—C7—C9	−65.46 (16)	C29—Si3—C39—C42	−152.29 (15)
C11—Si1—C7—C9	−179.52 (14)	C35—Si3—C39—C42	−36.26 (18)
Si2—Si1—C7—C9	49.69 (16)	Si4—Si3—C39—C42	94.50 (15)
C1—Si1—C7—C10	175.23 (15)	C29—Si3—C39—C41	86.91 (16)
C11—Si1—C7—C10	61.17 (17)	C35—Si3—C39—C41	−157.05 (14)
Si2—Si1—C7—C10	−69.62 (16)	Si4—Si3—C39—C41	−26.29 (16)
C1—Si1—C7—C8	55.22 (16)	C29—Si3—C39—C40	−33.92 (16)
C11—Si1—C7—C8	−58.84 (16)	C35—Si3—C39—C40	82.12 (16)
Si2—Si1—C7—C8	170.36 (12)	Si4—Si3—C39—C40	−147.12 (13)
C1—Si1—C11—C12	−31.94 (17)	C49—Si4—C43—C44	16.0 (2)
C7—Si1—C11—C12	85.10 (17)	C53—Si4—C43—C44	134.60 (17)
Si2—Si1—C11—C12	−144.76 (13)	Si3—Si4—C43—C44	−104.56 (17)
C1—Si1—C11—C13	89.01 (16)	C49—Si4—C43—C48	−165.72 (16)
C7—Si1—C11—C13	−153.95 (15)	C53—Si4—C43—C48	−47.08 (17)
Si2—Si1—C11—C13	−23.81 (18)	Si3—Si4—C43—C48	73.76 (16)
C1—Si1—C11—C14	−150.83 (15)	C48—C43—C44—C45	−2.2 (3)
C7—Si1—C11—C14	−33.80 (17)	Si4—C43—C44—C45	176.21 (16)
Si2—Si1—C11—C14	96.35 (14)	C43—C44—C45—C46	1.6 (3)
C21—Si2—C15—C20	−161.85 (15)	C44—C45—C46—C47	0.3 (3)
C25—Si2—C15—C20	−44.20 (17)	C45—C46—C47—C48	−1.4 (3)
Si1—Si2—C15—C20	76.66 (16)	C46—C47—C48—C43	0.7 (3)
C21—Si2—C15—C16	16.21 (19)	C44—C43—C48—C47	1.1 (3)
C25—Si2—C15—C16	133.86 (17)	Si4—C43—C48—C47	−177.41 (16)
Si1—Si2—C15—C16	−105.27 (17)	C43—Si4—C49—C50	−69.22 (18)
C20—C15—C16—C17	0.2 (3)	C53—Si4—C49—C50	176.22 (15)
Si2—C15—C16—C17	−177.96 (16)	Si3—Si4—C49—C50	45.46 (17)
C15—C16—C17—C18	0.8 (3)	C43—Si4—C49—C51	172.40 (17)
C16—C17—C18—C19	−1.0 (3)	C53—Si4—C49—C51	57.8 (2)
C17—C18—C19—C20	0.2 (3)	Si3—Si4—C49—C51	−72.91 (18)
C18—C19—C20—C15	0.9 (3)	C43—Si4—C49—C52	52.63 (18)
C16—C15—C20—C19	−1.0 (3)	C53—Si4—C49—C52	−61.93 (18)
Si2—C15—C20—C19	177.23 (15)	Si3—Si4—C49—C52	167.32 (14)
C15—Si2—C21—C22	−69.53 (15)	C43—Si4—C53—C54	86.34 (16)
C25—Si2—C21—C22	177.25 (13)	C49—Si4—C53—C54	−157.22 (15)
Si1—Si2—C21—C22	47.90 (15)	Si3—Si4—C53—C54	−27.26 (17)
C15—Si2—C21—C23	171.23 (14)	C43—Si4—C53—C56	−33.90 (16)
C25—Si2—C21—C23	58.01 (17)	C49—Si4—C53—C56	82.54 (17)
Si1—Si2—C21—C23	−71.34 (16)	Si3—Si4—C53—C56	−147.50 (13)
C15—Si2—C21—C24	51.39 (16)	C43—Si4—C53—C55	−152.98 (15)
C25—Si2—C21—C24	−61.83 (16)	C49—Si4—C53—C55	−36.55 (19)
Si1—Si2—C21—C24	168.82 (12)	Si3—Si4—C53—C55	93.41 (15)