Crystal structures of 2-bromo-1,1,1,3,3,3-hexa­methyl-2-(tri­methyl­sil­yl)tris­ilane and 2-bromo-1,1,1,3,3,3-hexa­isopropyl-2-(triiso­propyl­sil­yl)tri­silane

The synthesis and crystal structures of two tris­(tri­alkyl­sil­yl)silyl bromide compounds, C₉H₂₇BrSi₄ (I, HypSiBr) and C₂₇H₆₃BrSi₄ (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexa­methyl-2-(tri­methyl­sil­yl)tris­ilane using bromo­butane and 2,2′-azobis(2-methyl­propio­nitrile) as a radical initiator at 333 K. The mol­ecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si—Br bond distance is 2.2990 (12) Å and the Si—Si bond lengths are 2.3477 (8) Å. The Br—Si—Si bond angles are 104.83 (3)° and the Si—Si—Si bond angles are 113.69 (2)°, reflecting the steric hindrance inherent in the three tri­methyl­silyl groups attached to the central Si atom. Compound II was prepared in 55% yield by free-radical bromination of 1,1,1,3,3,3-hexa­isopropyl-2-(triiso­propyl­sil­yl)tris­ilane using N-bromo­succinimide and 2,2′-azobis(2-methyl­propio­nitrile) as a radical initiator at 353 K. Here the Si—Br bond length is 2.3185 (7) Å and the Si—Si bond lengths range from 2.443 (1) to 2.4628 (9) Å. The Br—Si—Si bond angles range from 98.44 (3) to 103.77 (3)°, indicating steric hindrance between the three triiso­propyl­silyl groups.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](Si-C) = 0.003 Å
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.028
• wR factor = 0.075
• Data-to-parameter ratio = 25.5

checkCIF/PLATON results

No syntax errors found



Datablock: I


Alert level C
PLAT242_ALERT_2_C Low    'MainMol' Ueq as Compared to Neighbors of        Si2 Check
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....        2.1 Note
PLAT601_ALERT_2_C Structure Contains Solvent Accessible VOIDS of .         57 Ang   3
PLAT978_ALERT_2_C Number C-C Bonds with Positive Residual Density.          0 Info

Alert level G
PLAT909_ALERT_3_G Percentage of I>2sig(I) Data at Theta(Max) Still        66% Note
PLAT996_ALERT_1_G Non-Standard SHELXL LIST 4 Style FCF Supplied ..          ! Check

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   4 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

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




Datablock: II


Alert level C
PLAT911_ALERT_3_C Missing FCF Refl Between Thmin & STh/L=    0.600         19 Report
PLAT978_ALERT_2_C Number C-C Bonds with Positive Residual Density.          0 Info

Alert level G
PLAT154_ALERT_1_G The s.u.'s on the Cell Angles are Equal ..(Note)      0.004 Degree
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600        130 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

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


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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Computing details

Data collection: APEX2 (Bruker, 2014) for (I); SMART (Bruker, 2014) for (II). For both structures, cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014). Program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) for (I); SHELXT2013 (Sheldrick, 2015a) for (II). Program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015b) for (I); SHELXL2014 (Sheldrick, 2015b) for (II). Molecular graphics: OLEX2 (Dolomanov et al., 2009; Bourhis et al., 2015) for (I); SHELXTL (Sheldrick, 2008) for (II). Software used to prepare material for publication: CrystalMaker (Palmer, 2007) for (I); SHELXTL (Sheldrick, 2008) for (II).

2-Bromo-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane (I)

Crystal data

C9H27BrSi4	Mo Kα radiation, λ = 0.71073 Å
Mr = 327.57	Cell parameters from 3863 reflections
Cubic, Pa3	θ = 2.3–25.3°
a = 15.6497 (19) Å	µ = 2.37 mm^−1
V = 3832.8 (14) Å^3	T = 173 K
Z = 8	Block, colourless
F(000) = 1376	0.45 × 0.24 × 0.14 mm
Dx = 1.135 Mg m^−3

Data collection

Bruker APEXII CCD diffractometer	953 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.046
Absorption correction: multi-scan (SADABS; Bruker, 2014)	θmax = 25.3°, θmin = 2.3°
Tmin = 0.571, Tmax = 0.745	h = −18→16
11038 measured reflections	k = −18→17
1174 independent reflections	l = −15→18

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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.075	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0349P)^2 + 1.4333P] where P = (Fo^2 + 2Fc^2)/3
1174 reflections	(Δ/σ)max = 0.002
46 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq
Br1	0.74011 (2)	0.74011 (2)	0.74011 (2)	0.04337 (17)
Si1	0.65529 (4)	0.65529 (4)	0.65529 (4)	0.0327 (3)
Si2	0.69238 (5)	0.51472 (4)	0.69229 (5)	0.0473 (2)
C1	0.6249 (2)	0.43945 (18)	0.6286 (2)	0.0734 (10)
H1A	0.6331	0.4506	0.5675	0.110*
H1B	0.5646	0.4478	0.6434	0.110*
H1C	0.6415	0.3805	0.6414	0.110*
C2	0.8079 (2)	0.49575 (19)	0.6707 (3)	0.0943 (14)
H2A	0.8227	0.4370	0.6866	0.141*
H2B	0.8422	0.5358	0.7044	0.141*
H2C	0.8194	0.5044	0.6098	0.141*
C3	0.6752 (3)	0.49746 (19)	0.8090 (2)	0.0953 (13)
H3A	0.6142	0.5032	0.8222	0.143*
H3B	0.7076	0.5401	0.8414	0.143*
H3C	0.6946	0.4401	0.8247	0.143*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.04337 (17)	0.04337 (17)	0.04337 (17)	−0.00621 (10)	−0.00621 (10)	−0.00621 (10)
Si1	0.0327 (3)	0.0327 (3)	0.0327 (3)	−0.0008 (3)	−0.0008 (3)	−0.0008 (3)
Si2	0.0529 (5)	0.0317 (4)	0.0573 (5)	−0.0013 (3)	−0.0106 (4)	0.0008 (3)
C1	0.087 (2)	0.0426 (16)	0.091 (2)	−0.0092 (16)	−0.0304 (19)	−0.0051 (16)
C2	0.056 (2)	0.0494 (19)	0.178 (4)	0.0145 (16)	−0.007 (2)	0.001 (2)
C3	0.168 (4)	0.052 (2)	0.066 (2)	0.006 (2)	−0.019 (2)	0.0183 (17)

Geometric parameters (Å, º)

Br1—Si1	2.2990 (12)	Si2—C1	1.870 (3)
Si1—Si2^i	2.3478 (8)	Si2—C2	1.862 (3)
Si1—Si2	2.3477 (8)	Si2—C3	1.866 (3)
Si1—Si2^ii	2.3478 (8)
Br1—Si1—Si2	104.83 (3)	C1—Si2—Si1	108.61 (10)
Br1—Si1—Si2^ii	104.83 (3)	C2—Si2—Si1	110.16 (11)
Br1—Si1—Si2^i	104.83 (3)	C2—Si2—C1	110.55 (17)
Si2—Si1—Si2^ii	113.69 (2)	C2—Si2—C3	107.12 (19)
Si2—Si1—Si2^i	113.69 (3)	C3—Si2—Si1	109.96 (10)
Si2^i—Si1—Si2^ii	113.69 (2)	C3—Si2—C1	110.45 (16)

Symmetry codes: (i) y, z, x; (ii) z, x, y.

2-Bromo-1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane (II)

Crystal data

C27H63BrSi4	Z = 2
Mr = 580.04	F(000) = 632
Triclinic, P1	Dx = 1.150 Mg m^−3
a = 8.4412 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.1336 (6) Å	Cell parameters from 8192 reflections
c = 18.8477 (10) Å	θ = 2.0–26.0°
α = 92.565 (4)°	µ = 1.38 mm^−1
β = 90.527 (4)°	T = 173 K
γ = 108.718 (4)°	Needles, colourless
V = 1675.44 (15) Å^3	0.38 × 0.10 × 0.02 mm

Data collection

Bruker SMART APEX CCD area detector diffractometer	6628 independent reflections
Radiation source: sealed tube	4752 reflections with I > 2σ(I)
Detector resolution: 8 pixels mm^-1	Rint = 0.057
ω and φ scans	θmax = 26.3°, θmin = 1.1°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −10→10
Tmin = 0.554, Tmax = 0.674	k = −13→13
21505 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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.075	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0274P)^2 + 0.3128P] where P = (Fo^2 + 2Fc^2)/3
6628 reflections	(Δ/σ)max = 0.001
307 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. All H atoms were positioned geometrically and refined using a riding model with C—H = 0.95–0.99 Å and wAith U_iso(H) = 1.2 (1.5 for methyl groups) times U_eq(C).

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

	x	y	z	Uiso*/Ueq
Br1	1.06221 (3)	0.19737 (3)	0.24790 (2)	0.02768 (9)
Si1	0.77723 (8)	0.16573 (6)	0.25116 (3)	0.01926 (16)
Si2	0.72101 (8)	0.26469 (7)	0.14487 (4)	0.02137 (17)
Si3	0.67829 (9)	−0.06634 (7)	0.24791 (4)	0.02310 (17)
Si4	0.74993 (9)	0.27556 (7)	0.36447 (4)	0.02177 (17)
C1	0.8269 (3)	0.4443 (2)	0.15761 (13)	0.0249 (6)
H1	0.7549	0.4757	0.1905	0.030*
C2	1.0018 (3)	0.4866 (3)	0.19270 (15)	0.0349 (7)
H2A	1.0777	0.4575	0.1626	0.052*
H2B	0.9962	0.4498	0.2393	0.052*
H2C	1.0435	0.5794	0.1987	0.052*
C3	0.8371 (4)	0.5176 (3)	0.08928 (14)	0.0335 (7)
H3A	0.8753	0.6091	0.1015	0.050*
H3B	0.7262	0.4931	0.0660	0.050*
H3C	0.9162	0.4972	0.0570	0.050*
C4	0.7935 (3)	0.1980 (3)	0.06084 (12)	0.0266 (6)
H4	0.7464	0.1034	0.0618	0.032*
C5	0.9832 (3)	0.2301 (3)	0.05683 (14)	0.0371 (7)
H5A	1.0101	0.1830	0.0161	0.056*
H5B	1.0268	0.2065	0.1006	0.056*
H5C	1.0345	0.3214	0.0513	0.056*
C6	0.7282 (4)	0.2347 (3)	−0.00855 (13)	0.0388 (7)
H6A	0.7814	0.3257	−0.0146	0.058*
H6B	0.6067	0.2155	−0.0066	0.058*
H6C	0.7549	0.1862	−0.0487	0.058*
C7	0.4836 (3)	0.2270 (2)	0.13810 (14)	0.0287 (6)
H7	0.4439	0.2136	0.1879	0.034*
C8	0.4264 (4)	0.3368 (3)	0.11280 (17)	0.0429 (8)
H8A	0.4536	0.3500	0.0627	0.064*
H8B	0.4841	0.4146	0.1414	0.064*
H8C	0.3053	0.3155	0.1182	0.064*
C9	0.3878 (3)	0.1029 (3)	0.09537 (15)	0.0394 (7)
H9A	0.2692	0.0772	0.1073	0.059*
H9B	0.4342	0.0360	0.1073	0.059*
H9C	0.3991	0.1169	0.0444	0.059*
C10	0.6700 (3)	−0.1257 (3)	0.15145 (13)	0.0304 (6)
H10	0.6105	−0.0769	0.1245	0.036*
C11	0.8446 (4)	−0.0949 (3)	0.11986 (15)	0.0402 (8)
H11A	0.9038	−0.1481	0.1406	0.060*
H11B	0.9078	−0.0052	0.1305	0.060*
H11C	0.8337	−0.1118	0.0683	0.060*
C12	0.5697 (4)	−0.2671 (3)	0.13666 (15)	0.0423 (8)
H12A	0.5798	−0.2910	0.0866	0.063*
H12B	0.4517	−0.2814	0.1470	0.063*
H12C	0.6138	−0.3189	0.1669	0.063*
C13	0.4641 (3)	−0.1251 (2)	0.28895 (14)	0.0278 (6)
H13	0.4741	−0.0754	0.3352	0.033*
C14	0.3289 (4)	−0.0951 (3)	0.24525 (16)	0.0426 (8)
H14A	0.3107	−0.1440	0.1997	0.064*
H14B	0.3651	−0.0041	0.2367	0.064*
H14C	0.2244	−0.1178	0.2714	0.064*
C15	0.4016 (4)	−0.2660 (3)	0.30713 (16)	0.0402 (7)
H15A	0.2967	−0.2836	0.3327	0.060*
H15B	0.4859	−0.2842	0.3371	0.060*
H15C	0.3827	−0.3196	0.2632	0.060*
C16	0.8392 (3)	−0.1171 (2)	0.29934 (14)	0.0292 (6)
H16	0.9513	−0.0608	0.2850	0.035*
C17	0.8383 (4)	−0.2537 (3)	0.28398 (15)	0.0383 (7)
H17A	0.9229	−0.2705	0.3143	0.057*
H17B	0.8637	−0.2649	0.2340	0.057*
H17C	0.7277	−0.3129	0.2938	0.057*
C18	0.8317 (4)	−0.0933 (3)	0.38032 (15)	0.0461 (8)
H18A	0.7258	−0.1494	0.3976	0.069*
H18B	0.8392	−0.0047	0.3909	0.069*
H18C	0.9252	−0.1109	0.4039	0.069*
C19	0.5967 (3)	0.1584 (2)	0.42272 (13)	0.0290 (6)
H19	0.6217	0.0766	0.4166	0.035*
C20	0.4130 (4)	0.1287 (3)	0.40018 (18)	0.0467 (8)
H20A	0.3450	0.0522	0.4228	0.070*
H20B	0.4012	0.1145	0.3484	0.070*
H20C	0.3751	0.2003	0.4149	0.070*
C21	0.6171 (4)	0.1952 (3)	0.50277 (14)	0.0486 (9)
H21A	0.5929	0.2749	0.5118	0.073*
H21B	0.7321	0.2064	0.5185	0.073*
H21C	0.5392	0.1280	0.5290	0.073*
C22	0.9557 (3)	0.3395 (2)	0.41777 (13)	0.0286 (6)
H22	0.9246	0.3756	0.4631	0.034*
C23	1.0335 (4)	0.2414 (3)	0.44175 (15)	0.0397 (7)
H23A	1.0703	0.2024	0.4002	0.059*
H23B	0.9504	0.1757	0.4669	0.059*
H23C	1.1299	0.2831	0.4736	0.059*
C24	1.0893 (3)	0.4526 (3)	0.38677 (14)	0.0364 (7)
H24A	1.1806	0.4887	0.4218	0.055*
H24B	1.0390	0.5175	0.3750	0.055*
H24C	1.1334	0.4236	0.3437	0.055*
C25	0.6831 (3)	0.4212 (2)	0.34999 (13)	0.0258 (6)
H25	0.7695	0.4766	0.3192	0.031*
C26	0.6873 (4)	0.5007 (3)	0.41963 (14)	0.0450 (8)
H26A	0.6597	0.5772	0.4092	0.067*
H26B	0.7994	0.5251	0.4417	0.067*
H26C	0.6053	0.4502	0.4522	0.067*
C27	0.5152 (4)	0.3988 (3)	0.31189 (15)	0.0392 (7)
H27A	0.4243	0.3572	0.3434	0.059*
H27B	0.5082	0.3445	0.2688	0.059*
H27C	0.5050	0.4803	0.2990	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02088 (14)	0.03279 (18)	0.02927 (15)	0.00846 (11)	0.00155 (11)	0.00149 (12)
Si1	0.0195 (4)	0.0190 (4)	0.0191 (4)	0.0060 (3)	0.0012 (3)	0.0007 (3)
Si2	0.0215 (4)	0.0220 (4)	0.0204 (4)	0.0066 (3)	0.0003 (3)	0.0017 (3)
Si3	0.0256 (4)	0.0192 (4)	0.0247 (4)	0.0076 (3)	0.0019 (3)	0.0009 (3)
Si4	0.0255 (4)	0.0205 (4)	0.0195 (4)	0.0075 (3)	0.0028 (3)	0.0008 (3)
C1	0.0272 (14)	0.0233 (15)	0.0229 (14)	0.0060 (12)	0.0038 (11)	0.0043 (11)
C2	0.0326 (16)	0.0281 (17)	0.0391 (17)	0.0031 (13)	−0.0053 (13)	0.0016 (13)
C3	0.0416 (18)	0.0255 (16)	0.0336 (16)	0.0103 (13)	0.0054 (13)	0.0078 (13)
C4	0.0325 (15)	0.0280 (16)	0.0199 (13)	0.0110 (12)	−0.0005 (11)	−0.0002 (11)
C5	0.0398 (18)	0.049 (2)	0.0266 (15)	0.0205 (15)	0.0080 (13)	0.0018 (14)
C6	0.0447 (18)	0.047 (2)	0.0228 (15)	0.0122 (15)	−0.0018 (13)	−0.0007 (14)
C7	0.0234 (15)	0.0325 (17)	0.0306 (15)	0.0091 (12)	−0.0023 (12)	0.0033 (13)
C8	0.0280 (16)	0.044 (2)	0.059 (2)	0.0136 (14)	−0.0057 (15)	0.0083 (16)
C9	0.0287 (16)	0.0406 (19)	0.0425 (18)	0.0022 (14)	−0.0059 (13)	0.0037 (14)
C10	0.0392 (17)	0.0255 (16)	0.0284 (15)	0.0138 (13)	0.0009 (13)	−0.0026 (12)
C11	0.053 (2)	0.0409 (19)	0.0339 (16)	0.0245 (15)	0.0101 (15)	0.0006 (14)
C12	0.055 (2)	0.0358 (19)	0.0371 (17)	0.0182 (16)	−0.0091 (15)	−0.0096 (14)
C13	0.0281 (15)	0.0207 (15)	0.0328 (15)	0.0053 (12)	0.0030 (12)	0.0029 (12)
C14	0.0303 (17)	0.044 (2)	0.052 (2)	0.0098 (14)	0.0021 (14)	0.0088 (15)
C15	0.0404 (18)	0.0301 (17)	0.0447 (18)	0.0030 (14)	0.0061 (14)	0.0067 (14)
C16	0.0312 (15)	0.0220 (16)	0.0371 (16)	0.0119 (12)	−0.0010 (12)	0.0045 (12)
C17	0.0431 (18)	0.0310 (18)	0.0456 (18)	0.0180 (14)	0.0007 (15)	0.0072 (14)
C18	0.062 (2)	0.042 (2)	0.0410 (18)	0.0268 (17)	−0.0133 (16)	−0.0041 (15)
C19	0.0364 (16)	0.0218 (16)	0.0287 (15)	0.0086 (12)	0.0091 (12)	0.0038 (12)
C20	0.0369 (18)	0.0338 (19)	0.069 (2)	0.0089 (14)	0.0210 (16)	0.0101 (16)
C21	0.075 (2)	0.036 (2)	0.0324 (17)	0.0132 (17)	0.0229 (16)	0.0069 (14)
C22	0.0327 (16)	0.0310 (17)	0.0212 (14)	0.0097 (13)	−0.0035 (12)	−0.0036 (12)
C23	0.0491 (19)	0.042 (2)	0.0312 (16)	0.0197 (15)	−0.0109 (14)	−0.0033 (14)
C24	0.0348 (17)	0.0362 (18)	0.0322 (16)	0.0041 (14)	−0.0043 (13)	−0.0040 (13)
C25	0.0347 (16)	0.0231 (15)	0.0211 (13)	0.0117 (12)	0.0018 (12)	−0.0006 (11)
C26	0.077 (2)	0.0380 (19)	0.0302 (16)	0.0336 (17)	−0.0023 (16)	−0.0064 (14)
C27	0.0388 (18)	0.0384 (19)	0.0464 (18)	0.0213 (14)	−0.0010 (14)	0.0007 (15)

Geometric parameters (Å, º)

Br1—Si1	2.3185 (7)	C12—H12B	0.9800
Si1—Si2	2.4430 (10)	C12—H12C	0.9800
Si1—Si3	2.4448 (10)	C13—C14	1.531 (4)
Si1—Si4	2.4628 (9)	C13—C15	1.541 (4)
Si2—C4	1.908 (2)	C13—H13	1.0000
Si2—C7	1.913 (3)	C14—H14A	0.9800
Si2—C1	1.914 (3)	C14—H14B	0.9800
Si3—C10	1.899 (3)	C14—H14C	0.9800
Si3—C13	1.899 (3)	C15—H15A	0.9800
Si3—C16	1.903 (3)	C15—H15B	0.9800
Si4—C22	1.909 (3)	C15—H15C	0.9800
Si4—C25	1.910 (3)	C16—C17	1.533 (4)
Si4—C19	1.911 (3)	C16—C18	1.543 (4)
C1—C2	1.532 (3)	C16—H16	1.0000
C1—C3	1.543 (4)	C17—H17A	0.9800
C1—H1	1.0000	C17—H17B	0.9800
C2—H2A	0.9800	C17—H17C	0.9800
C2—H2B	0.9800	C18—H18A	0.9800
C2—H2C	0.9800	C18—H18B	0.9800
C3—H3A	0.9800	C18—H18C	0.9800
C3—H3B	0.9800	C19—C20	1.530 (4)
C3—H3C	0.9800	C19—C21	1.539 (4)
C4—C5	1.528 (4)	C19—H19	1.0000
C4—C6	1.536 (4)	C20—H20A	0.9800
C4—H4	1.0000	C20—H20B	0.9800
C5—H5A	0.9800	C20—H20C	0.9800
C5—H5B	0.9800	C21—H21A	0.9800
C5—H5C	0.9800	C21—H21B	0.9800
C6—H6A	0.9800	C21—H21C	0.9800
C6—H6B	0.9800	C22—C23	1.525 (4)
C6—H6C	0.9800	C22—C24	1.538 (4)
C7—C9	1.543 (4)	C22—H22	1.0000
C7—C8	1.544 (4)	C23—H23A	0.9800
C7—H7	1.0000	C23—H23B	0.9800
C8—H8A	0.9800	C23—H23C	0.9800
C8—H8B	0.9800	C24—H24A	0.9800
C8—H8C	0.9800	C24—H24B	0.9800
C9—H9A	0.9800	C24—H24C	0.9800
C9—H9B	0.9800	C25—C27	1.525 (4)
C9—H9C	0.9800	C25—C26	1.543 (3)
C10—C11	1.534 (4)	C25—H25	1.0000
C10—C12	1.541 (4)	C26—H26A	0.9800
C10—H10	1.0000	C26—H26B	0.9800
C11—H11A	0.9800	C26—H26C	0.9800
C11—H11B	0.9800	C27—H27A	0.9800
C11—H11C	0.9800	C27—H27B	0.9800
C12—H12A	0.9800	C27—H27C	0.9800
Br1—Si1—Si2	103.77 (3)	C10—C12—H12C	109.5
Br1—Si1—Si3	98.44 (3)	H12A—C12—H12C	109.5
Si2—Si1—Si3	116.55 (3)	H12B—C12—H12C	109.5
Br1—Si1—Si4	102.65 (3)	C14—C13—C15	109.5 (2)
Si2—Si1—Si4	115.02 (4)	C14—C13—Si3	112.65 (19)
Si3—Si1—Si4	116.59 (4)	C15—C13—Si3	116.31 (18)
C4—Si2—C7	108.70 (11)	C14—C13—H13	105.9
C4—Si2—C1	111.49 (12)	C15—C13—H13	105.9
C7—Si2—C1	109.69 (11)	Si3—C13—H13	105.9
C4—Si2—Si1	112.06 (9)	C13—C14—H14A	109.5
C7—Si2—Si1	106.40 (9)	C13—C14—H14B	109.5
C1—Si2—Si1	108.35 (8)	H14A—C14—H14B	109.5
C10—Si3—C13	111.22 (12)	C13—C14—H14C	109.5
C10—Si3—C16	109.44 (12)	H14A—C14—H14C	109.5
C13—Si3—C16	111.50 (12)	H14B—C14—H14C	109.5
C10—Si3—Si1	107.75 (9)	C13—C15—H15A	109.5
C13—Si3—Si1	109.78 (8)	C13—C15—H15B	109.5
C16—Si3—Si1	106.98 (9)	H15A—C15—H15B	109.5
C22—Si4—C25	104.78 (12)	C13—C15—H15C	109.5
C22—Si4—C19	106.42 (12)	H15A—C15—H15C	109.5
C25—Si4—C19	111.59 (12)	H15B—C15—H15C	109.5
C22—Si4—Si1	112.92 (8)	C17—C16—C18	108.9 (2)
C25—Si4—Si1	111.74 (8)	C17—C16—Si3	116.29 (19)
C19—Si4—Si1	109.24 (8)	C18—C16—Si3	112.56 (18)
C2—C1—C3	107.7 (2)	C17—C16—H16	106.1
C2—C1—Si2	115.52 (18)	C18—C16—H16	106.1
C3—C1—Si2	114.54 (18)	Si3—C16—H16	106.1
C2—C1—H1	106.1	C16—C17—H17A	109.5
C3—C1—H1	106.1	C16—C17—H17B	109.5
Si2—C1—H1	106.1	H17A—C17—H17B	109.5
C1—C2—H2A	109.5	C16—C17—H17C	109.5
C1—C2—H2B	109.5	H17A—C17—H17C	109.5
H2A—C2—H2B	109.5	H17B—C17—H17C	109.5
C1—C2—H2C	109.5	C16—C18—H18A	109.5
H2A—C2—H2C	109.5	C16—C18—H18B	109.5
H2B—C2—H2C	109.5	H18A—C18—H18B	109.5
C1—C3—H3A	109.5	C16—C18—H18C	109.5
C1—C3—H3B	109.5	H18A—C18—H18C	109.5
H3A—C3—H3B	109.5	H18B—C18—H18C	109.5
C1—C3—H3C	109.5	C20—C19—C21	109.0 (2)
H3A—C3—H3C	109.5	C20—C19—Si4	113.92 (19)
H3B—C3—H3C	109.5	C21—C19—Si4	114.62 (19)
C5—C4—C6	108.5 (2)	C20—C19—H19	106.2
C5—C4—Si2	114.13 (17)	C21—C19—H19	106.2
C6—C4—Si2	114.24 (19)	Si4—C19—H19	106.2
C5—C4—H4	106.5	C19—C20—H20A	109.5
C6—C4—H4	106.5	C19—C20—H20B	109.5
Si2—C4—H4	106.5	H20A—C20—H20B	109.5
C4—C5—H5A	109.5	C19—C20—H20C	109.5
C4—C5—H5B	109.5	H20A—C20—H20C	109.5
H5A—C5—H5B	109.5	H20B—C20—H20C	109.5
C4—C5—H5C	109.5	C19—C21—H21A	109.5
H5A—C5—H5C	109.5	C19—C21—H21B	109.5
H5B—C5—H5C	109.5	H21A—C21—H21B	109.5
C4—C6—H6A	109.5	C19—C21—H21C	109.5
C4—C6—H6B	109.5	H21A—C21—H21C	109.5
H6A—C6—H6B	109.5	H21B—C21—H21C	109.5
C4—C6—H6C	109.5	C23—C22—C24	110.6 (2)
H6A—C6—H6C	109.5	C23—C22—Si4	116.47 (19)
H6B—C6—H6C	109.5	C24—C22—Si4	115.61 (18)
C9—C7—C8	109.7 (2)	C23—C22—H22	104.1
C9—C7—Si2	115.43 (18)	C24—C22—H22	104.1
C8—C7—Si2	114.49 (19)	Si4—C22—H22	104.1
C9—C7—H7	105.4	C22—C23—H23A	109.5
C8—C7—H7	105.4	C22—C23—H23B	109.5
Si2—C7—H7	105.4	H23A—C23—H23B	109.5
C7—C8—H8A	109.5	C22—C23—H23C	109.5
C7—C8—H8B	109.5	H23A—C23—H23C	109.5
H8A—C8—H8B	109.5	H23B—C23—H23C	109.5
C7—C8—H8C	109.5	C22—C24—H24A	109.5
H8A—C8—H8C	109.5	C22—C24—H24B	109.5
H8B—C8—H8C	109.5	H24A—C24—H24B	109.5
C7—C9—H9A	109.5	C22—C24—H24C	109.5
C7—C9—H9B	109.5	H24A—C24—H24C	109.5
H9A—C9—H9B	109.5	H24B—C24—H24C	109.5
C7—C9—H9C	109.5	C27—C25—C26	108.5 (2)
H9A—C9—H9C	109.5	C27—C25—Si4	117.05 (18)
H9B—C9—H9C	109.5	C26—C25—Si4	112.35 (18)
C11—C10—C12	110.3 (2)	C27—C25—H25	106.0
C11—C10—Si3	112.34 (19)	C26—C25—H25	106.0
C12—C10—Si3	115.08 (19)	Si4—C25—H25	106.0
C11—C10—H10	106.1	C25—C26—H26A	109.5
C12—C10—H10	106.1	C25—C26—H26B	109.5
Si3—C10—H10	106.1	H26A—C26—H26B	109.5
C10—C11—H11A	109.5	C25—C26—H26C	109.5
C10—C11—H11B	109.5	H26A—C26—H26C	109.5
H11A—C11—H11B	109.5	H26B—C26—H26C	109.5
C10—C11—H11C	109.5	C25—C27—H27A	109.5
H11A—C11—H11C	109.5	C25—C27—H27B	109.5
H11B—C11—H11C	109.5	H27A—C27—H27B	109.5
C10—C12—H12A	109.5	C25—C27—H27C	109.5
C10—C12—H12B	109.5	H27A—C27—H27C	109.5
H12A—C12—H12B	109.5	H27B—C27—H27C	109.5
C13—Si3—C10—C11	−172.26 (19)	C10—Si3—C13—C14	−52.9 (2)
C16—Si3—C10—C11	−48.6 (2)	C16—Si3—C13—C14	−175.32 (19)
Si1—Si3—C10—C11	67.4 (2)	Si1—Si3—C13—C14	66.3 (2)
C13—Si3—C10—C12	−44.9 (2)	C10—Si3—C13—C15	74.7 (2)
C16—Si3—C10—C12	78.8 (2)	C16—Si3—C13—C15	−47.8 (2)
Si1—Si3—C10—C12	−165.25 (18)	Si1—Si3—C13—C15	−166.17 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5B···Br1	0.98	2.80	3.711 (3)	155
C16—H16···Br1	1.00	2.84	3.584 (3)	131
C23—H23A···Br1	0.98	2.87	3.685 (3)	142
C24—H24C···Br1	0.98	2.93	3.726 (3)	139