[Bis­(trimethylsilyl)amido-κN]{tert-butyl[(E)-2-(tert-butyl­imino)­ethyl]amido-κ²N,N′}tin(II), a key inter­mediate in the synthesis of 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diaza­stannole

The title compound, [Sn(C₁₀H₂₁N₂)(C₆H₁₈NSi₂)], contains the Sn^II centre in a trigonal–pyramidal geometry. The basal plane is formed by three N atoms and the fourth apical position is occupied by a stereoactive lone pair. The Sn atom is displaced from the plane of the three N atoms by 1.1968 (12) Å. The Sn—N bonds are highly polarized toward the N atoms, as confirmed by natural bonding orbital analysis.

S1. Comment

The unsaturated N-heterocyclic divalent compounds of group 14 elements are key intermediates in many reactions (Arduengo, 1999; Gans-Eichler et al., 2002; Haaf et al., 2000; Hill & West, 2004; Hill et al., 2005; Naka et al., 2004; Tumanskii et al., 2004, 2005). The chemistry of the C, Si and Ge analogues has been explored (e.g. Haaf et al., 1998, 2000; Hill et al., 2005; Naka et al., 2004). However, the chemistry of the Sn congener has largely remained unknown. The first synthetic procedure for the preparation of 1,3-di-tert-butyl-2,3-dihydro-1H-[1,3,2]diazastannole, (I), was recently reported by Gans-Eichler et al. (2002) as a six-step synthesis. The experimental support for the proposed mechanism was based on detection of the title key intermediate, (II), by ¹H NMR spectroscopy. In the course of our studies of the chemistry of (I), we reproduced its synthesis (Gans-Eichler et al., 2002) and successfully isolated and characterized the key intermediate, (II), thus obtaining direct evidence for the proposed mechanism. Here, we report the synthesis and structural and spectroscopic characterization of (II), and the results of our theoretical studies of a model analogue, (II-DFT).

Numerous attempts to prepare compound (I) in a toluene–hexane mixture and to isolate its crystals, as described by Gans-Eichler et al. (2002), were unsuccessful. We were able to obtain a sample of diazastannole (I) as a mixture with stannylene (II) in a 1:4 ratio only in the presence of HN(SiMe₃)₂, as suggested by the ¹ NMR spectrum. Compound (I) is characterized by a remarkable thermal instability and decomposes at 333 K (Gans-Eichler et al., 2002). Our data suggest that the presence of some additives is necessary in order to promote the conversion of (II) into (I) and to improve the thermal stability of diazastannole (I). Additionally, preliminary density functional theory (DFT) studies of similar systems indicate that the conversion of (II) to (I) and appropriate byproducts is favoured by about 5 kcal mol⁻¹ (1 kcal mol⁻¹ = 4.184 kJ mol⁻¹).

To ascertain fully the formation of (II) during the synthesis, its solid-state structure was established by single-crystal X-ray analysis. The molecular structure of (II) is shown in Fig. 1, and important bond distances and angles are presented in Table 1. Compound (II) crystallizes in a triclinic space group as discrete monomeric molecules with no intermolecular Sn···Sn or Sn···N interactions. The Sn centre is trigonal–pyramidal, with three N atoms in the basal plane and a stereochemically active lone pair in the fourth vertex. Atom Sn1 is displaced from the plane defined by atoms N1, N2, and N3 by 1.1968 (12) Å. Similar geometries have been reported for a number of Sn^II compounds [Cambridge Structural Database (CSD), Version?; Allen, 2002].

We have also performed a density functional theory (DFT) study of a model analogue of (II), (MeNH═CH—CH₂—NMe)Sn[N(SiH₃)₂], (II-DFT), using GAUSSIAN03 (Frisch et al., 2004) at different levels of theory and selected the PBE1PBE/SDD combination as the best. In 2000, Ayers et al. demonstrated that DFT methods produce reliable results for trigonal–pyramidal Ge and Sn systems similar to (II). The results of the geometry optimization and natural bonding orbital analysis (NBO; Weinhold, 2001) of (II-DFT) are discussed below.

In (II), the tert-butyl-{2-[(E)-tert-butylimino]ethyl}amine ligand coordinates to the Sn centre in an asymmetric four-electron σ-bonding k²-fashion, forming a five-membered heterocycle. The Sn1—N1 and Sn1—N2 distances to the bidentate ligand [2.278 (2) and 2.139 (2) Å, respectively] clearly demonstrate the distinction between formally dative and formally covalent bonds. However, such a dramatic difference is hardly expected based on the sum of the angles about atoms N1 and N2: atom N1 is sp²-hybridized [the sum of the angles about N1 is 358.6 (2)°] and atom N2 exhibits a slight sp³ character [the sum of the angles about N2 is 356.0 (2)°]. Both Sn—N distances fall in the expected range for single Sn—N bonds (Reference for standard values?). These observations are in accord with the theoretical findings for (II-DFT), in which the Sn1—N1 distance is 2.36 Å and Sn1—N2 = 2.12 Å. The distance to the third N atom, Sn1—N3 [2.150 (2) Å], is similar to Sn1—N2 and somewhat longer than the relevant Sn—N(SiMe₃)₂ distance of 2.08 (4) Å obtained by averaging the distances in eight compounds selected from the CSD based on rigorous search criteria. The corresponding value in (II-DFT) of 2.13 Å is in excellent agreement with the observed distance.

The NBO analysis suggests that compound (II-DFT) is highly ionic, with the Sn—N bonds strongly polarized toward the N atoms. The Sn lone pair is sp^0.21-hybridized, indicating predominant s character, an observation in harmony with Bent's rule (Reference?). The ionic nature of this metal complex is also evident from the high natural charges: Sn1 1.32, N1 − 0.60, N2 − 0.98 and N3 − 1.72. The Sn1—N3 bond distance is not the shortest among the three Sn1—N bonds because atom N3 bears two SiH₃ groups with an average positive charge of 0.48.

The five-membered heterocycle is in an envelope conformation, with Sn1 being the flip atom. Atom Sn1 is displaced from the plane defined by atoms N1/C5/C6/N2 by 0.383 (5) Å. The flip angle of the envelope, defined as the dihedral angle between the planes defined by atoms N1/C5/C6/N2 and N1/Sn1/N2 is 12.70 (19)°. In the theoretical model, (II-DFT), the five-membered ring is substantially more planar, with a small 0.07 Å displacement of Sn1 from the plane defined by N1/C5/C6/N2 and a 2.3° envelope-folding angle. Interestingly, the orientation of the Sn1—N3 vector relative to the plane of the heterocycle is different in (II) and (II-DFT). This is illustrated by the C5—(midpoint of bond C5—C6)—Sn1—N3 torsion angle. In (II), this angle is 89.1°, but in (II-DFT), the N(SiH₃)₂ substituent is considerably more tilted to the side of C5, at 79.7°.

The tert-butyl-{2-[(E)-tert-butylimino]ethyl}amide bite angle N1—Sn1—N2 in (II) spans 75.37 (8)°, a value typical of ligands forming five-membered rings with an Sn centre. This magnitude is in good agreement with the average of 18 angles in ten relevant Sn compounds found in the CSD [77 (3)°], and with the angle of 73.4° computed for (II-DFT). It is noteworthy that the other two N—Sn1—N angles in (II) average 100 (1)°, while in (II-DFT) they were much closer to a right angle [average 92.3 (5)°], corresponding to a small extent of orbital hybridization at the metal centre.

Finally, the solid-state structure of (II) exhibits some positional disorder: each methyl group at C4 is disordered over two positions in a 53:47 ratio.

S2. Experimental

The title stannylene, (II), was prepared according to the literature procedure of Gans-Eichler et al. (2002). Orange crystals of (II) suitable for X-ray analysis were obtained by recrystallization of the crude product from a small volume of hexane. Spectroscopic analysis: ¹H NMR (C₆D₆, δ, p.p.m.): 0.45 (s, 18H, SiMe₃), 1.04 (s, 9H, tert-Bu), 1.36 (s, 9H, tert-Bu), 3.82 [dd, ²J(H,H) = 25 Hz], 4.49 [dd, ²J(H,H) = 25 Hz], 7.31 (s, 1H, N═ CH); ¹³C{¹H} NMR (C₆D₆, δ, p.p.m.): 6.85, 30.55, 31.64, 54.32, 59.08, 60.34, 172.45.

S3. Refinement

All H atoms were placed in idealized locations and refined as riding, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C) for atom C5, C—H = 0.99 Å and U_iso(H) = 1.2U_eq(C) for atom C6, and C—H = 0.98 Å and U_iso(H) = 1.5U_eq(C) for methyl groups.

Computing details

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2003); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. The molecular structure of (II). Displacement ellipsoids are drawn at the 50% probability level. The minor components of the disordered C atoms, and all H atoms except those on atoms C5 and C6, have been omitted for clarity.

{tert-Butyl[(E)-2-(tert-butylimino)ethyl]amido-k²N,N'} [bis(trimethylsilyl)amido-κN]tin(II)

Crystal data

[Sn(C10H21N2)(C3H9NSi)2]	Z = 2
Mr = 448.37	F(000) = 468
Triclinic, P1	Dx = 1.304 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 9.2875 (3) Å	Cell parameters from 7833 reflections
b = 10.3056 (3) Å	θ = 2.2–28.3°
c = 13.3897 (4) Å	µ = 1.23 mm^−1
α = 81.468 (1)°	T = 100 K
β = 85.416 (1)°	Block, orange
γ = 64.270 (1)°	0.39 × 0.34 × 0.23 mm
V = 1141.55 (6) Å^3

Data collection

Bruker SMART1000 CCD area-detector diffractometer	5449 independent reflections
Radiation source: fine-focus sealed tube	5137 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.015
0.30° ω scans	θmax = 28.3°, θmin = 2.2°
Absorption correction: multi-scan SADABS (Bruker, 2003)	h = −12→12
Tmin = 0.646, Tmax = 0.766	k = −13→13
10674 measured reflections	l = −17→17

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.080	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0373P)^2 + 1.7884P] where P = (Fo^2 + 2Fc^2)/3
5449 reflections	(Δ/σ)max = 0.001
207 parameters	Δρmax = 2.38 e Å^−3
18 restraints	Δρmin = −1.36 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	Occ. (<1)
Sn1	0.028703 (18)	0.713095 (18)	0.164792 (12)	0.02073 (6)
Si1	0.34523 (8)	0.76262 (7)	0.10775 (5)	0.01769 (13)
Si2	0.34167 (8)	0.63405 (8)	0.32425 (5)	0.02181 (14)
N1	−0.1289 (3)	0.7970 (2)	0.30162 (16)	0.0241 (4)
N2	0.0318 (3)	0.5227 (2)	0.25555 (16)	0.0207 (4)
N3	0.2529 (2)	0.7000 (2)	0.20843 (15)	0.0182 (4)
C1	−0.0866 (7)	1.0028 (8)	0.3275 (7)	0.0380 (5)	0.469 (8)
H1A	−0.0258	0.9501	0.3887	0.057*	0.469 (8)
H1B	−0.1360	1.1072	0.3324	0.057*	0.469 (8)
H1C	−0.0145	0.9831	0.2684	0.057*	0.469 (8)
C2	−0.3238 (9)	1.0293 (8)	0.2242 (5)	0.0380 (5)	0.469 (8)
H2A	−0.2568	1.0314	0.1642	0.057*	0.469 (8)
H2B	−0.3965	1.1289	0.2355	0.057*	0.469 (8)
H2C	−0.3862	0.9764	0.2140	0.057*	0.469 (8)
C3	−0.3302 (9)	0.9773 (9)	0.4105 (5)	0.0380 (5)	0.469 (8)
H3A	−0.4184	0.9535	0.3990	0.057*	0.469 (8)
H3B	−0.3732	1.0792	0.4222	0.057*	0.469 (8)
H3C	−0.2705	0.9147	0.4697	0.057*	0.469 (8)
C1A	−0.1106 (7)	1.0313 (6)	0.2801 (6)	0.0380 (5)	0.531 (8)
H1A1	−0.0102	0.9841	0.3170	0.057*	0.531 (8)
H1A2	−0.1662	1.1331	0.2924	0.057*	0.531 (8)
H1A3	−0.0877	1.0268	0.2076	0.057*	0.531 (8)
C2A	−0.3619 (7)	1.0181 (7)	0.2454 (5)	0.0380 (5)	0.531 (8)
H2A1	−0.3250	0.9949	0.1769	0.057*	0.531 (8)
H2A2	−0.4149	1.1237	0.2448	0.057*	0.531 (8)
H2A3	−0.4376	0.9769	0.2696	0.057*	0.531 (8)
C3A	−0.2878 (9)	0.9763 (8)	0.4229 (4)	0.0380 (5)	0.531 (8)
H3A1	−0.3522	0.9216	0.4405	0.057*	0.531 (8)
H3A2	−0.3555	1.0799	0.4253	0.057*	0.531 (8)
H3A3	−0.2012	0.9423	0.4713	0.057*	0.531 (8)
C4	−0.2171 (3)	0.9529 (3)	0.3166 (2)	0.0380 (5)
C5	−0.1613 (3)	0.6975 (3)	0.3557 (2)	0.0222 (5)
H5	−0.2360	0.7220	0.4104	0.027*
C6	−0.0833 (3)	0.5479 (3)	0.3328 (2)	0.0240 (5)
H6A	−0.0321	0.4837	0.3949	0.029*
H6B	−0.1662	0.5202	0.3141	0.029*
C7	0.0995 (3)	0.3770 (3)	0.22139 (19)	0.0219 (5)
C8	−0.0266 (4)	0.3542 (3)	0.1688 (3)	0.0354 (7)
H8A	−0.1136	0.3587	0.2168	0.053*
H8B	0.0223	0.2590	0.1444	0.053*
H8C	−0.0693	0.4303	0.1116	0.053*
C9	0.1672 (4)	0.2578 (3)	0.3111 (2)	0.0348 (6)
H9A	0.2459	0.2743	0.3455	0.052*
H9B	0.2188	0.1628	0.2865	0.052*
H9C	0.0802	0.2604	0.3584	0.052*
C10	0.2361 (3)	0.3656 (3)	0.1468 (2)	0.0299 (6)
H10A	0.1939	0.4366	0.0868	0.045*
H10B	0.2875	0.2675	0.1270	0.045*
H10C	0.3146	0.3854	0.1786	0.045*
C11	0.3205 (4)	0.7033 (3)	−0.0133 (2)	0.0304 (6)
H11A	0.3481	0.5991	−0.0026	0.046*
H11B	0.3911	0.7226	−0.0657	0.046*
H11C	0.2092	0.7572	−0.0347	0.046*
C12	0.2599 (4)	0.9650 (3)	0.0898 (2)	0.0372 (7)
H12A	0.1459	1.0054	0.0747	0.056*
H12B	0.3159	0.9972	0.0335	0.056*
H12C	0.2730	0.9988	0.1516	0.056*
C13	0.5670 (3)	0.6935 (4)	0.1198 (2)	0.0324 (6)
H13A	0.5899	0.7178	0.1829	0.049*
H13B	0.6089	0.7388	0.0625	0.049*
H13C	0.6180	0.5879	0.1202	0.049*
C14	0.4055 (4)	0.7650 (3)	0.3698 (2)	0.0329 (6)
H14A	0.4791	0.7848	0.3200	0.049*
H14B	0.4594	0.7225	0.4345	0.049*
H14C	0.3113	0.8558	0.3785	0.049*
C15	0.5194 (4)	0.4533 (3)	0.3217 (2)	0.0374 (7)
H15A	0.4838	0.3807	0.3089	0.056*
H15B	0.5728	0.4235	0.3869	0.056*
H15C	0.5942	0.4615	0.2680	0.056*
C16	0.2134 (4)	0.6005 (5)	0.4297 (2)	0.0447 (9)
H16A	0.1233	0.6927	0.4416	0.067*
H16B	0.2766	0.5575	0.4911	0.067*
H16C	0.1728	0.5338	0.4118	0.067*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.01591 (9)	0.02862 (10)	0.01527 (9)	−0.00829 (7)	−0.00088 (6)	0.00071 (6)
Si1	0.0205 (3)	0.0179 (3)	0.0157 (3)	−0.0096 (2)	0.0020 (2)	−0.0020 (2)
Si2	0.0240 (3)	0.0318 (4)	0.0149 (3)	−0.0175 (3)	−0.0023 (2)	0.0004 (3)
N1	0.0254 (11)	0.0201 (10)	0.0218 (10)	−0.0049 (8)	0.0028 (8)	−0.0049 (8)
N2	0.0236 (10)	0.0174 (9)	0.0219 (10)	−0.0100 (8)	0.0062 (8)	−0.0047 (8)
N3	0.0174 (9)	0.0215 (9)	0.0162 (9)	−0.0097 (8)	−0.0005 (7)	0.0002 (7)
C1	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C2	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C3	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C1A	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C2A	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C3A	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C4	0.0401 (12)	0.0249 (8)	0.0438 (12)	−0.0097 (8)	0.0099 (9)	−0.0081 (8)
C5	0.0174 (11)	0.0228 (11)	0.0252 (12)	−0.0078 (9)	0.0050 (9)	−0.0052 (9)
C6	0.0199 (11)	0.0265 (12)	0.0283 (13)	−0.0116 (10)	0.0028 (10)	−0.0080 (10)
C7	0.0209 (11)	0.0193 (11)	0.0251 (12)	−0.0079 (9)	0.0015 (9)	−0.0049 (9)
C8	0.0264 (14)	0.0290 (14)	0.0523 (19)	−0.0087 (11)	−0.0037 (13)	−0.0177 (13)
C9	0.0367 (16)	0.0223 (13)	0.0347 (15)	−0.0045 (12)	0.0016 (12)	0.0006 (11)
C10	0.0274 (13)	0.0262 (13)	0.0351 (15)	−0.0102 (11)	0.0079 (11)	−0.0094 (11)
C11	0.0376 (15)	0.0428 (16)	0.0188 (12)	−0.0251 (13)	0.0060 (11)	−0.0059 (11)
C12	0.0528 (19)	0.0218 (13)	0.0339 (15)	−0.0153 (13)	0.0087 (14)	−0.0014 (11)
C13	0.0243 (13)	0.0486 (17)	0.0272 (14)	−0.0186 (13)	0.0050 (11)	−0.0062 (12)
C14	0.0378 (15)	0.0440 (16)	0.0265 (13)	−0.0245 (14)	−0.0004 (11)	−0.0112 (12)
C15	0.0402 (16)	0.0306 (14)	0.0363 (16)	−0.0108 (13)	−0.0202 (13)	0.0069 (12)
C16	0.0442 (18)	0.087 (3)	0.0193 (13)	−0.0463 (19)	−0.0043 (12)	0.0061 (15)

Geometric parameters (Å, º)

Sn1—N2	2.139 (2)	C3A—H3A2	0.9800
Sn1—N3	2.150 (2)	C3A—H3A3	0.9800
Sn1—N1	2.278 (2)	C5—C6	1.460 (3)
Si1—N3	1.734 (2)	C5—H5	0.9500
Si1—C12	1.867 (3)	C6—H6A	0.9900
Si1—C13	1.876 (3)	C6—H6B	0.9900
Si1—C11	1.879 (3)	C7—C10	1.524 (4)
Si2—N3	1.718 (2)	C7—C8	1.531 (4)
Si2—C16	1.864 (3)	C7—C9	1.536 (4)
Si2—C15	1.880 (3)	C8—H8A	0.9800
Si2—C14	1.882 (3)	C8—H8B	0.9800
N1—C5	1.295 (3)	C8—H8C	0.9800
N1—C4	1.490 (4)	C9—H9A	0.9800
N2—C6	1.394 (3)	C9—H9B	0.9800
N2—C7	1.482 (3)	C9—H9C	0.9800
C1—C4	1.532 (4)	C10—H10A	0.9800
C1—H1A	0.9800	C10—H10B	0.9800
C1—H1B	0.9800	C10—H10C	0.9800
C1—H1C	0.9800	C11—H11A	0.9800
C2—C4	1.537 (4)	C11—H11B	0.9800
C2—H2A	0.9800	C11—H11C	0.9800
C2—H2B	0.9800	C12—H12A	0.9800
C2—H2C	0.9800	C12—H12B	0.9800
C3—C4	1.550 (4)	C12—H12C	0.9800
C3—H3A	0.9800	C13—H13A	0.9800
C3—H3B	0.9800	C13—H13B	0.9800
C3—H3C	0.9800	C13—H13C	0.9800
C1A—C4	1.539 (4)	C14—H14A	0.9800
C1A—H1A1	0.9800	C14—H14B	0.9800
C1A—H1A2	0.9800	C14—H14C	0.9800
C1A—H1A3	0.9800	C15—H15A	0.9800
C2A—C4	1.549 (4)	C15—H15B	0.9800
C2A—H2A1	0.9800	C15—H15C	0.9800
C2A—H2A2	0.9800	C16—H16A	0.9800
C2A—H2A3	0.9800	C16—H16B	0.9800
C3A—C4	1.527 (4)	C16—H16C	0.9800
C3A—H3A1	0.9800
N2—Sn1—N3	99.15 (8)	C2A—C4—C3	90.8 (4)
N2—Sn1—N1	75.37 (8)	N1—C5—C6	120.1 (2)
N3—Sn1—N1	101.21 (8)	N1—C5—H5	119.9
N3—Si1—C12	111.27 (12)	C6—C5—H5	119.9
N3—Si1—C13	114.48 (12)	N2—C6—C5	114.9 (2)
C12—Si1—C13	106.95 (16)	N2—C6—H6A	108.5
N3—Si1—C11	111.27 (11)	C5—C6—H6A	108.5
C12—Si1—C11	107.83 (15)	N2—C6—H6B	108.5
C13—Si1—C11	104.60 (13)	C5—C6—H6B	108.5
N3—Si2—C16	115.78 (12)	H6A—C6—H6B	107.5
N3—Si2—C15	111.76 (12)	N2—C7—C10	108.2 (2)
C16—Si2—C15	104.11 (17)	N2—C7—C8	111.1 (2)
N3—Si2—C14	111.55 (12)	C10—C7—C8	108.9 (2)
C16—Si2—C14	103.84 (15)	N2—C7—C9	110.5 (2)
C15—Si2—C14	109.22 (14)	C10—C7—C9	108.3 (2)
C5—N1—C4	121.6 (2)	C8—C7—C9	109.8 (2)
C5—N1—Sn1	112.02 (16)	C7—C8—H8A	109.5
C4—N1—Sn1	124.96 (16)	C7—C8—H8B	109.5
C6—N2—C7	116.6 (2)	H8A—C8—H8B	109.5
C6—N2—Sn1	115.33 (16)	C7—C8—H8C	109.5
C7—N2—Sn1	124.07 (16)	H8A—C8—H8C	109.5
Si2—N3—Si1	121.19 (12)	H8B—C8—H8C	109.5
Si2—N3—Sn1	127.69 (11)	C7—C9—H9A	109.5
Si1—N3—Sn1	111.11 (10)	C7—C9—H9B	109.5
C4—C1—H1A	109.5	H9A—C9—H9B	109.5
C4—C1—H1B	109.5	C7—C9—H9C	109.5
C4—C1—H1C	109.5	H9A—C9—H9C	109.5
C4—C2—H2A	109.5	H9B—C9—H9C	109.5
C4—C2—H2B	109.5	C7—C10—H10A	109.5
C4—C2—H2C	109.5	C7—C10—H10B	109.5
C4—C3—H3A	109.5	H10A—C10—H10B	109.5
C4—C3—H3B	109.5	C7—C10—H10C	109.5
C4—C3—H3C	109.5	H10A—C10—H10C	109.5
C4—C1A—H1A1	109.5	H10B—C10—H10C	109.5
C4—C1A—H1A2	109.5	Si1—C11—H11A	109.5
H1A1—C1A—H1A2	109.5	Si1—C11—H11B	109.5
C4—C1A—H1A3	109.5	H11A—C11—H11B	109.5
H1A1—C1A—H1A3	109.5	Si1—C11—H11C	109.5
H1A2—C1A—H1A3	109.5	H11A—C11—H11C	109.5
C4—C2A—H2A1	109.5	H11B—C11—H11C	109.5
C4—C2A—H2A2	109.5	Si1—C12—H12A	109.5
H2A1—C2A—H2A2	109.5	Si1—C12—H12B	109.5
C4—C2A—H2A3	109.5	H12A—C12—H12B	109.5
H2A1—C2A—H2A3	109.5	Si1—C12—H12C	109.5
H2A2—C2A—H2A3	109.5	H12A—C12—H12C	109.5
C4—C3A—H3A1	109.5	H12B—C12—H12C	109.5
C4—C3A—H3A2	109.5	Si1—C13—H13A	109.5
H3A1—C3A—H3A2	109.5	Si1—C13—H13B	109.5
C4—C3A—H3A3	109.5	H13A—C13—H13B	109.5
H3A1—C3A—H3A3	109.5	Si1—C13—H13C	109.5
H3A2—C3A—H3A3	109.5	H13A—C13—H13C	109.5
N1—C4—C3A	113.5 (3)	H13B—C13—H13C	109.5
N1—C4—C1	104.9 (3)	Si2—C14—H14A	109.5
C3A—C4—C1	95.9 (4)	Si2—C14—H14B	109.5
N1—C4—C2	106.5 (3)	H14A—C14—H14B	109.5
C3A—C4—C2	120.0 (4)	Si2—C14—H14C	109.5
C1—C4—C2	114.9 (5)	H14A—C14—H14C	109.5
N1—C4—C1A	109.1 (3)	H14B—C14—H14C	109.5
C3A—C4—C1A	114.8 (4)	Si2—C15—H15A	109.5
C1—C4—C1A	25.2 (3)	Si2—C15—H15B	109.5
C2—C4—C1A	90.3 (4)	H15A—C15—H15B	109.5
N1—C4—C2A	106.3 (3)	Si2—C15—H15C	109.5
C3A—C4—C2A	105.6 (4)	H15A—C15—H15C	109.5
C1—C4—C2A	130.4 (4)	H15B—C15—H15C	109.5
C2—C4—C2A	17.9 (3)	Si2—C16—H16A	109.5
C1A—C4—C2A	106.9 (4)	Si2—C16—H16B	109.5
N1—C4—C3	113.0 (4)	H16A—C16—H16B	109.5
C3A—C4—C3	16.2 (4)	Si2—C16—H16C	109.5
C1—C4—C3	111.0 (4)	H16A—C16—H16C	109.5
C2—C4—C3	106.5 (4)	H16B—C16—H16C	109.5
C1A—C4—C3	127.0 (4)
N2—Sn1—N1—C5	−10.99 (18)	C5—N1—C4—C3A	25.5 (5)
N3—Sn1—N1—C5	−107.65 (19)	Sn1—N1—C4—C3A	−169.3 (4)
N2—Sn1—N1—C4	−177.4 (2)	C5—N1—C4—C1	128.9 (4)
N3—Sn1—N1—C4	85.9 (2)	Sn1—N1—C4—C1	−65.9 (4)
N3—Sn1—N2—C6	112.68 (18)	C5—N1—C4—C2	−108.8 (4)
N1—Sn1—N2—C6	13.39 (17)	Sn1—N1—C4—C2	56.4 (4)
N3—Sn1—N2—C7	−90.74 (19)	C5—N1—C4—C1A	154.9 (4)
N1—Sn1—N2—C7	170.0 (2)	Sn1—N1—C4—C1A	−39.9 (4)
C16—Si2—N3—Si1	170.04 (18)	C5—N1—C4—C2A	−90.2 (4)
C15—Si2—N3—Si1	−70.99 (18)	Sn1—N1—C4—C2A	75.0 (4)
C14—Si2—N3—Si1	51.60 (18)	C5—N1—C4—C3	7.8 (5)
C16—Si2—N3—Sn1	−11.7 (2)	Sn1—N1—C4—C3	173.0 (4)
C15—Si2—N3—Sn1	107.26 (16)	C4—N1—C5—C6	174.2 (2)
C14—Si2—N3—Sn1	−130.15 (15)	Sn1—N1—C5—C6	7.2 (3)
C12—Si1—N3—Si2	−100.64 (17)	C7—N2—C6—C5	−172.7 (2)
C13—Si1—N3—Si2	20.75 (19)	Sn1—N2—C6—C5	−14.3 (3)
C11—Si1—N3—Si2	139.08 (15)	N1—C5—C6—N2	4.2 (4)
C12—Si1—N3—Sn1	80.84 (16)	C6—N2—C7—C10	−173.1 (2)
C13—Si1—N3—Sn1	−157.77 (12)	Sn1—N2—C7—C10	30.6 (3)
C11—Si1—N3—Sn1	−39.44 (15)	C6—N2—C7—C8	67.4 (3)
N2—Sn1—N3—Si2	−33.35 (15)	Sn1—N2—C7—C8	−88.9 (3)
N1—Sn1—N3—Si2	43.42 (15)	C6—N2—C7—C9	−54.7 (3)
N2—Sn1—N3—Si1	145.05 (10)	Sn1—N2—C7—C9	148.96 (19)
N1—Sn1—N3—Si1	−138.18 (10)