2-Acetyl-amino-1,3,4,6-tetra-O-(tri-methyl-silyl)-2-de-oxy-α-d-gluco-pyran-ose.

The title compound, C20H47NO6Si4, was synthesized by per-O-tri-methyl-silylation of N-acetyl-d-glucosa-mine using chloro-tri-methyl-silane in the presence of hexa-methyl-disiloxane. The tri-methyl-silyl group and acetamido group are located on the same side of the pyran ring, showing an α-configuration glycoside. One of the tri-methyl-silyl groups is disordered over two orientations, with site-occupancy factors of 0.625 (9) and 0.375 (9). In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into supra-molecular chains along the a-axis direction.

Related literature

For background to the title compound, see: Augé et al. (1985 ▶); Ronnow et al. (1994 ▶); Du & Gervais-Hague (2005 ▶); Wang et al. (2007 ▶); Witschi & Gervais-Hague (2010 ▶). For related structures, see: Odinokov et al. (2002 ▶); Hu et al. (2011 ▶). For the synthesis, see: Loganathan & Trivedi (1987 ▶); Jervis et al. (2010 ▶).

Experimental

Crystal data

C20H47NO6Si4

M = 509.95

Orthorhombic,

a = 9.4500 (7) Å

b = 12.8824 (9) Å

c = 27.295 (3) Å

V = 3322.9 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.21 mm−1

T = 293 K

0.38 × 0.20 × 0.19 mm

Data collection

Agilent Xcalibur (Atlas, Gemini ultra) diffractometer

Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T min = 0.926, T max = 0.962

9896 measured reflections

3438 independent reflections

2105 reflections with I > 2σ(I)

R int = 0.046

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.149

S = 1.01

3438 reflections

309 parameters

183 restraints

H-atom parameters constrained

Δρmax = 0.26 e Å−3

Δρmin = −0.22 e Å−3

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: OLEX2.

Click here for additional data file.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681301266X/zq2199sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681301266X/zq2199Isup2.hkl

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

C20H47NO6Si4	F(000) = 1112
Mr = 509.95	Dx = 1.019 Mg m−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1672 reflections
a = 9.4500 (7) Å	θ = 3.2–29.6°
b = 12.8824 (9) Å	µ = 0.21 mm−1
c = 27.295 (3) Å	T = 293 K
V = 3322.9 (5) Å3	Needle, colourless
Z = 4	0.38 × 0.20 × 0.19 mm

Agilent Xcalibur (Atlas, Gemini ultra) diffractometer	3438 independent reflections
Radiation source: fine-focus sealed tube	2105 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
Detector resolution: 10.3592 pixels mm-1	θmax = 25.4°, θmin = 3.2°
ω scans	h = −11→10
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −12→15
Tmin = 0.926, Tmax = 0.962	l = −30→32
9896 measured reflections

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.149	H-atom parameters constrained
S = 1.01	w = 1/[σ2(Fo2) + (0.0744P)2 + 0.3973P] where P = (Fo2 + 2Fc2)/3
3438 reflections	(Δ/σ)max < 0.001
309 parameters	Δρmax = 0.26 e Å−3
183 restraints	Δρmin = −0.22 e Å−3

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. 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 > 2sigma(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	Occ. (<1)
Si1	1.01789 (16)	0.89841 (11)	0.87673 (6)	0.0716 (4)
Si2	1.03616 (19)	0.43173 (13)	0.99519 (7)	0.0911 (6)
Si3	0.9320 (2)	0.31145 (12)	0.84396 (7)	0.0842 (5)
Si4	0.5209 (19)	0.5532 (8)	0.7757 (5)	0.1318 (13)	0.625 (9)
O1	0.7944 (3)	0.6870 (3)	0.85017 (13)	0.0726 (9)
O2	0.9849 (3)	0.7739 (2)	0.88456 (12)	0.0662 (9)
O3	0.7055 (3)	0.7511 (5)	1.00819 (18)	0.1157 (16)
O4	0.9211 (3)	0.4785 (3)	0.95578 (13)	0.0731 (10)
O5	0.9704 (4)	0.4351 (3)	0.85373 (13)	0.0751 (9)
O6	0.6763 (5)	0.5183 (4)	0.79227 (17)	0.1117 (16)
N1	0.9130 (3)	0.7012 (3)	0.97859 (14)	0.0604 (11)
H1	1.0030	0.6991	0.9831	0.072*
C1	0.8492 (5)	0.7328 (4)	0.8930 (2)	0.0646 (13)
H1A	0.7863	0.7895	0.9029	0.077*
C2	0.8562 (4)	0.6535 (4)	0.93482 (18)	0.0581 (12)
H2	0.7590	0.6320	0.9421	0.070*
C3	0.9380 (4)	0.5563 (4)	0.91906 (17)	0.0593 (12)
H3	1.0386	0.5733	0.9156	0.071*
C4	0.8818 (5)	0.5161 (4)	0.87110 (18)	0.0612 (12)
H4	0.7863	0.4886	0.8762	0.073*
C5	0.8759 (5)	0.6012 (4)	0.83238 (19)	0.0690 (14)
H5	0.9723	0.6250	0.8253	0.083*
C6	1.0050 (8)	0.9663 (5)	0.9361 (2)	0.113 (2)
H6A	0.9109	0.9591	0.9489	0.170*
H6B	1.0262	1.0386	0.9316	0.170*
H6C	1.0714	0.9366	0.9588	0.170*
C7	1.1984 (6)	0.9046 (5)	0.8523 (2)	0.0970 (19)
H7A	1.2648	0.8907	0.8781	0.146*
H7B	1.2156	0.9726	0.8392	0.146*
H7C	1.2093	0.8538	0.8269	0.146*
C8	0.8876 (7)	0.9521 (5)	0.8333 (3)	0.113 (2)
H8A	0.8682	0.9019	0.8082	0.169*
H8B	0.9251	1.0140	0.8186	0.169*
H8C	0.8017	0.9684	0.8504	0.169*
C9	0.8345 (5)	0.7478 (5)	1.0119 (2)	0.0715 (15)
C10	0.9086 (6)	0.7965 (5)	1.0546 (2)	0.0879 (17)
H10A	0.9505	0.8610	1.0446	0.132*
H10B	0.9812	0.7505	1.0662	0.132*
H10C	0.8417	0.8092	1.0804	0.132*
C11	1.0461 (9)	0.5095 (7)	1.0526 (2)	0.140 (3)
H11A	1.0800	0.5780	1.0452	0.209*
H11B	1.1097	0.4765	1.0752	0.209*
H11C	0.9537	0.5141	1.0671	0.209*
C12	1.2153 (7)	0.4319 (6)	0.9680 (3)	0.129 (3)
H12A	1.2113	0.4030	0.9356	0.194*
H12B	1.2776	0.3909	0.9880	0.194*
H12C	1.2500	0.5018	0.9663	0.194*
C13	0.9806 (11)	0.2963 (6)	1.0071 (4)	0.163 (4)
H13A	0.8920	0.2963	1.0243	0.245*
H13B	1.0511	0.2621	1.0266	0.245*
H13C	0.9698	0.2603	0.9765	0.245*
C14	1.0962 (9)	0.2396 (5)	0.8588 (3)	0.132 (3)
H14A	1.1755	0.2733	0.8436	0.198*
H14B	1.0888	0.1697	0.8468	0.198*
H14C	1.1094	0.2384	0.8937	0.198*
C15	0.7800 (8)	0.2703 (6)	0.8809 (3)	0.124 (3)
H15A	0.7923	0.2935	0.9140	0.185*
H15B	0.7732	0.1959	0.8803	0.185*
H15C	0.6950	0.2998	0.8676	0.185*
C16	0.8882 (11)	0.2878 (5)	0.7775 (3)	0.140 (3)
H16A	0.8026	0.3239	0.7692	0.210*
H16B	0.8754	0.2147	0.7721	0.210*
H16C	0.9642	0.3126	0.7573	0.210*
C17	0.8067 (7)	0.5670 (5)	0.7852 (2)	0.0922 (18)
H17A	0.7933	0.6271	0.7643	0.111*
H17B	0.8697	0.5195	0.7683	0.111*
C18A	0.4994 (16)	0.7084 (13)	0.7939 (6)	0.161 (3)	0.625 (9)
H18A	0.5411	0.7212	0.8254	0.242*	0.625 (9)
H18B	0.4013	0.7276	0.7946	0.242*	0.625 (9)
H18C	0.5476	0.7488	0.7695	0.242*	0.625 (9)
C19	0.5118 (19)	0.5859 (15)	0.7098 (5)	0.151 (3)	0.625 (9)
H19A	0.5719	0.6443	0.7032	0.226*	0.625 (9)
H19B	0.4161	0.6028	0.7012	0.226*	0.625 (9)
H19C	0.5428	0.5275	0.6908	0.226*	0.625 (9)
C20A	0.3849 (15)	0.4802 (14)	0.8078 (6)	0.170 (3)	0.625 (9)
H20A	0.3810	0.4162	0.7898	0.255*	0.625 (9)
H20B	0.2932	0.5124	0.8076	0.255*	0.625 (9)
H20C	0.4128	0.4665	0.8410	0.255*	0.625 (9)
Si4A	0.515 (3)	0.5685 (12)	0.7787 (8)	0.1318 (13)	0.375 (9)
C18	0.445 (3)	0.639 (2)	0.8231 (9)	0.161 (3)	0.375 (9)
H18D	0.4651	0.6110	0.8550	0.242*	0.375 (9)
H18E	0.3448	0.6441	0.8186	0.242*	0.375 (9)
H18F	0.4868	0.7069	0.8204	0.242*	0.375 (9)
C20	0.432 (3)	0.4260 (15)	0.7663 (10)	0.170 (3)	0.375 (9)
H20D	0.4911	0.3823	0.7465	0.255*	0.375 (9)
H20E	0.3431	0.4366	0.7502	0.255*	0.375 (9)
H20F	0.4164	0.3934	0.7975	0.255*	0.375 (9)
C19A	0.480 (3)	0.526 (3)	0.7151 (9)	0.151 (3)	0.375 (9)
H19D	0.5197	0.5750	0.6926	0.226*	0.375 (9)
H19E	0.3795	0.5215	0.7100	0.226*	0.375 (9)
H19F	0.5217	0.4589	0.7098	0.226*	0.375 (9)

	U11	U22	U33	U12	U13	U23
Si1	0.0804 (9)	0.0542 (8)	0.0802 (9)	−0.0045 (7)	0.0034 (8)	0.0013 (8)
Si2	0.1054 (12)	0.0709 (10)	0.0970 (12)	0.0005 (9)	−0.0386 (10)	0.0153 (9)
Si3	0.1152 (12)	0.0534 (8)	0.0839 (10)	−0.0089 (9)	−0.0044 (10)	−0.0025 (8)
Si4	0.1162 (18)	0.180 (3)	0.0987 (19)	0.026 (3)	−0.0233 (15)	−0.043 (2)
O1	0.078 (2)	0.058 (2)	0.082 (2)	0.0030 (19)	−0.0269 (19)	0.001 (2)
O2	0.0583 (17)	0.0556 (19)	0.085 (2)	−0.0022 (15)	−0.0030 (16)	−0.0010 (17)
O3	0.0407 (19)	0.177 (4)	0.129 (4)	0.011 (2)	0.009 (2)	−0.036 (3)
O4	0.0725 (19)	0.068 (2)	0.079 (2)	−0.0113 (19)	−0.0134 (18)	0.0178 (19)
O5	0.087 (2)	0.0523 (18)	0.086 (2)	0.0013 (19)	−0.0010 (19)	0.0020 (18)
O6	0.130 (3)	0.094 (3)	0.111 (3)	−0.025 (3)	−0.054 (3)	0.004 (3)
N1	0.0321 (15)	0.079 (3)	0.070 (3)	0.0023 (19)	0.0012 (18)	−0.009 (2)
C1	0.054 (3)	0.059 (3)	0.080 (4)	0.006 (2)	−0.008 (2)	−0.004 (3)
C2	0.038 (2)	0.069 (3)	0.067 (3)	−0.001 (2)	−0.005 (2)	0.000 (3)
C3	0.048 (2)	0.058 (3)	0.072 (3)	−0.005 (2)	−0.005 (2)	0.010 (3)
C4	0.064 (3)	0.052 (3)	0.067 (3)	−0.008 (2)	−0.009 (2)	0.000 (3)
C5	0.076 (3)	0.057 (3)	0.074 (3)	−0.001 (3)	−0.008 (3)	0.000 (3)
C6	0.158 (6)	0.078 (4)	0.104 (5)	−0.008 (4)	0.023 (5)	−0.022 (4)
C7	0.100 (4)	0.096 (5)	0.095 (4)	−0.015 (4)	−0.003 (4)	0.010 (4)
C8	0.112 (5)	0.074 (4)	0.153 (7)	0.011 (4)	−0.012 (4)	0.027 (5)
C9	0.047 (3)	0.088 (4)	0.080 (4)	0.002 (3)	0.005 (3)	0.004 (3)
C10	0.073 (3)	0.116 (5)	0.074 (4)	0.005 (4)	0.008 (3)	−0.014 (4)
C11	0.167 (7)	0.158 (7)	0.093 (5)	0.037 (6)	−0.053 (5)	0.003 (5)
C12	0.099 (5)	0.118 (6)	0.172 (7)	0.030 (5)	−0.046 (5)	0.004 (6)
C13	0.186 (8)	0.117 (6)	0.186 (9)	−0.038 (6)	−0.079 (7)	0.073 (6)
C14	0.157 (6)	0.056 (4)	0.183 (9)	0.009 (4)	−0.006 (6)	−0.007 (5)
C15	0.148 (6)	0.089 (5)	0.134 (6)	−0.038 (5)	0.013 (5)	−0.015 (5)
C16	0.244 (10)	0.087 (5)	0.089 (5)	−0.013 (6)	−0.029 (6)	−0.012 (4)
C17	0.128 (5)	0.076 (4)	0.072 (4)	−0.005 (4)	−0.026 (4)	0.002 (3)
C18A	0.143 (5)	0.204 (7)	0.137 (6)	0.032 (5)	−0.018 (5)	−0.040 (5)
C19	0.128 (5)	0.202 (7)	0.122 (5)	0.031 (6)	−0.036 (4)	−0.032 (6)
C20A	0.145 (5)	0.218 (7)	0.148 (6)	0.008 (6)	−0.015 (5)	−0.032 (6)
Si4A	0.1162 (18)	0.180 (3)	0.0987 (19)	0.026 (3)	−0.0233 (15)	−0.043 (2)
C18	0.143 (5)	0.204 (7)	0.137 (6)	0.032 (5)	−0.018 (5)	−0.040 (5)
C20	0.145 (5)	0.218 (7)	0.148 (6)	0.008 (6)	−0.015 (5)	−0.032 (6)
C19A	0.128 (5)	0.202 (7)	0.122 (5)	0.031 (6)	−0.036 (4)	−0.032 (6)

Si1—O2	1.649 (4)	C9—C10	1.498 (8)
Si1—C7	1.833 (6)	C10—H10A	0.9600
Si1—C8	1.845 (7)	C10—H10B	0.9600
Si1—C6	1.847 (6)	C10—H10C	0.9600
Si2—O4	1.644 (4)	C11—H11A	0.9600
Si2—C12	1.848 (8)	C11—H11B	0.9600
Si2—C13	1.851 (8)	C11—H11C	0.9600
Si2—C11	1.863 (7)	C12—H12A	0.9600
Si3—O5	1.655 (4)	C12—H12B	0.9600
Si3—C15	1.833 (7)	C12—H12C	0.9600
Si3—C14	1.851 (8)	C13—H13A	0.9600
Si3—C16	1.886 (7)	C13—H13B	0.9600
Si4—O6	1.60 (2)	C13—H13C	0.9600
Si4—C18	1.846 (10)	C14—H14A	0.9600
Si4—C19	1.850 (9)	C14—H14B	0.9600
Si4—C20	1.858 (10)	C14—H14C	0.9600
O1—C1	1.408 (6)	C15—H15A	0.9600
O1—C5	1.432 (6)	C15—H15B	0.9600
O2—C1	1.406 (6)	C15—H15C	0.9600
O3—C9	1.224 (5)	C16—H16A	0.9600
O4—C3	1.427 (5)	C16—H16B	0.9600
O5—C4	1.419 (6)	C16—H16C	0.9600
O6—C17	1.396 (7)	C17—H17A	0.9700
O6—Si4A	1.69 (3)	C17—H17B	0.9700
N1—C9	1.317 (6)	C18A—Si4A	1.856 (10)
N1—C2	1.447 (6)	C18A—H18A	0.9600
N1—H1	0.8600	C18A—H18B	0.9600
C1—C2	1.532 (7)	C18A—H18C	0.9600
C1—H1A	0.9800	C19—H19A	0.9600
C2—C3	1.533 (6)	C19—H19B	0.9600
C2—H2	0.9800	C19—H19C	0.9600
C3—C4	1.505 (6)	C20A—Si4A	1.856 (10)
C3—H3	0.9800	C20A—H20A	0.9600
C4—C5	1.525 (7)	C20A—H20B	0.9600
C4—H4	0.9800	C20A—H20C	0.9600
C5—C17	1.511 (7)	Si4A—C19A	1.851 (10)
C5—H5	0.9800	C18—H18D	0.9600
C6—H6A	0.9600	C18—H18E	0.9600
C6—H6B	0.9600	C18—H18F	0.9600
C6—H6C	0.9600	C20—H20D	0.9600
C7—H7A	0.9600	C20—H20E	0.9600
C7—H7B	0.9600	C20—H20F	0.9600
C7—H7C	0.9600	C19A—H19D	0.9600
C8—H8A	0.9600	C19A—H19E	0.9600
C8—H8B	0.9600	C19A—H19F	0.9600
C8—H8C	0.9600
O2—Si1—C7	105.4 (3)	Si1—C8—H8C	109.5
O2—Si1—C8	108.8 (3)	H8A—C8—H8C	109.5
C7—Si1—C8	111.8 (3)	H8B—C8—H8C	109.5
O2—Si1—C6	109.6 (3)	O3—C9—N1	121.3 (5)
C7—Si1—C6	111.1 (3)	O3—C9—C10	121.0 (5)
C8—Si1—C6	110.1 (4)	N1—C9—C10	117.7 (4)
O4—Si2—C12	110.0 (3)	C9—C10—H10A	109.5
O4—Si2—C13	105.8 (3)	C9—C10—H10B	109.5
C12—Si2—C13	109.4 (4)	H10A—C10—H10B	109.5
O4—Si2—C11	112.8 (3)	C9—C10—H10C	109.5
C12—Si2—C11	106.9 (4)	H10A—C10—H10C	109.5
C13—Si2—C11	111.9 (5)	H10B—C10—H10C	109.5
O5—Si3—C15	111.2 (3)	Si2—C11—H11A	109.5
O5—Si3—C14	105.2 (3)	Si2—C11—H11B	109.5
C15—Si3—C14	113.1 (4)	H11A—C11—H11B	109.5
O5—Si3—C16	111.0 (3)	Si2—C11—H11C	109.5
C15—Si3—C16	108.0 (4)	H11A—C11—H11C	109.5
C14—Si3—C16	108.3 (4)	H11B—C11—H11C	109.5
O6—Si4—C18	109.0 (12)	Si2—C12—H12A	109.5
O6—Si4—C19	112.4 (9)	Si2—C12—H12B	109.5
C18—Si4—C19	121.8 (15)	H12A—C12—H12B	109.5
O6—Si4—C20	101.9 (11)	Si2—C12—H12C	109.5
C18—Si4—C20	116.8 (15)	H12A—C12—H12C	109.5
C19—Si4—C20	92.6 (13)	H12B—C12—H12C	109.5
C1—O1—C5	114.0 (3)	Si2—C13—H13A	109.5
C1—O2—Si1	124.1 (3)	Si2—C13—H13B	109.5
C3—O4—Si2	130.0 (3)	H13A—C13—H13B	109.5
C4—O5—Si3	129.2 (3)	Si2—C13—H13C	109.5
C17—O6—Si4	130.2 (5)	H13A—C13—H13C	109.5
C17—O6—Si4A	126.2 (7)	H13B—C13—H13C	109.5
C9—N1—C2	123.7 (4)	Si3—C14—H14A	109.5
C9—N1—H1	118.2	Si3—C14—H14B	109.5
C2—N1—H1	118.2	H14A—C14—H14B	109.5
O2—C1—O1	110.9 (4)	Si3—C14—H14C	109.5
O2—C1—C2	109.5 (3)	H14A—C14—H14C	109.5
O1—C1—C2	110.8 (4)	H14B—C14—H14C	109.5
O2—C1—H1A	108.5	Si3—C15—H15A	109.5
O1—C1—H1A	108.5	Si3—C15—H15B	109.5
C2—C1—H1A	108.5	H15A—C15—H15B	109.5
N1—C2—C1	110.3 (4)	Si3—C15—H15C	109.5
N1—C2—C3	113.1 (3)	H15A—C15—H15C	109.5
C1—C2—C3	110.9 (4)	H15B—C15—H15C	109.5
N1—C2—H2	107.4	Si3—C16—H16A	109.5
C1—C2—H2	107.4	Si3—C16—H16B	109.5
C3—C2—H2	107.4	H16A—C16—H16B	109.5
O4—C3—C4	109.2 (4)	Si3—C16—H16C	109.5
O4—C3—C2	108.7 (4)	H16A—C16—H16C	109.5
C4—C3—C2	110.3 (4)	H16B—C16—H16C	109.5
O4—C3—H3	109.5	O6—C17—C5	113.3 (5)
C4—C3—H3	109.5	O6—C17—H17A	108.9
C2—C3—H3	109.5	C5—C17—H17A	108.9
O5—C4—C3	109.6 (4)	O6—C17—H17B	108.9
O5—C4—C5	108.6 (4)	C5—C17—H17B	108.9
C3—C4—C5	111.6 (4)	H17A—C17—H17B	107.7
O5—C4—H4	109.0	Si4A—C18A—H18A	109.5
C3—C4—H4	109.0	Si4A—C18A—H18B	109.5
C5—C4—H4	109.0	H18A—C18A—H18B	109.5
O1—C5—C17	106.4 (4)	Si4A—C18A—H18C	109.5
O1—C5—C4	109.9 (4)	H18A—C18A—H18C	109.5
C17—C5—C4	113.4 (4)	H18B—C18A—H18C	109.5
O1—C5—H5	109.0	Si4A—C20A—H20A	109.5
C17—C5—H5	109.0	Si4A—C20A—H20B	109.5
C4—C5—H5	109.0	H20A—C20A—H20B	109.5
Si1—C6—H6A	109.5	Si4A—C20A—H20C	109.5
Si1—C6—H6B	109.5	H20A—C20A—H20C	109.5
H6A—C6—H6B	109.5	H20B—C20A—H20C	109.5
Si1—C6—H6C	109.5	O6—Si4A—C19A	104.8 (14)
H6A—C6—H6C	109.5	O6—Si4A—C18A	113.3 (14)
H6B—C6—H6C	109.5	C19A—Si4A—C18A	118.8 (17)
Si1—C7—H7A	109.5	O6—Si4A—C20A	105.7 (12)
Si1—C7—H7B	109.5	C19A—Si4A—C20A	95.6 (16)
H7A—C7—H7B	109.5	C18A—Si4A—C20A	116.5 (14)
Si1—C7—H7C	109.5	Si4A—C19A—H19D	109.5
H7A—C7—H7C	109.5	Si4A—C19A—H19E	109.5
H7B—C7—H7C	109.5	H19D—C19A—H19E	109.5
Si1—C8—H8A	109.5	Si4A—C19A—H19F	109.5
Si1—C8—H8B	109.5	H19D—C19A—H19F	109.5
H8A—C8—H8B	109.5	H19E—C19A—H19F	109.5

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O3i	0.86	2.03	2.855 (4)	160

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O3i	0.86	2.03	2.855 (4)	160

Symmetry code: (i) .