(S)-1,2-Dimethyl-1,1,2-triphenyl-2-(4-piperidiniometh­yl)disilane chloride

Däschlein, C.; Gessner, V.H.; Strohmann, C.

doi:10.1107/S1600536808028808

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 10| October 2008| Page o1950

doi:10.1107/S1600536808028808

Open

access

(S)-1,2-Dimethyl-1,1,2-triphenyl-2-(4-piperidiniomethyl)disilane chloride

Christian Däschlein,^a Viktoria H. Gessner ^a and Carsten Strohmann ^a ^*

^aAnorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
^*Correspondence e-mail: mail@carsten-strohmann.de

(Received 18 August 2008; accepted 8 September 2008; online 17 September 2008)

The title compound, C₂₆H₃₄NSi₂⁺·Cl⁻, shows chirality at silicon. Because of its highly selective synthesis with an e.r. of >99:1 by means of a racemic resolution with mandelic acid, the free disilane is of great importance to the chemistry of highly enantiomerically enriched lithiosilanes and their trapping products. N—H⋯Cl hydrogen bonding is present between the protonated nitrogen atom of the piperidino group and the chloride counter-anion. The silicon–silicon distance as well as silicon–carbon and carbon–nitrogen bond lengths are in the same ranges as in other quaternary, functionalized di- and tetrasilanes.

Related literature

For details of lithiosilanes, see: Lickiss & Smith (1995 ); Sekiguchi et al. (2000 ); Strohmann et al. (2001 , 2006 ); Strohmann & Däschlein (2008a ,b ); Tamao & Kawachi (1995 ). For enantiomerically enriched lithiosilanes, see: Colomer & Corriu (1976 ); Oestreich et al. (2005 ); Omote et al. (2000 ); Sommer & Mason (1965 ); Strohmann et al. (2007 ). For the determination of the absolute configuration of the disilane as the mandelic acid adduct, see: Strohmann et al. (2002 ). For related literature on hydrochlorides of amines, see: Farrugia et al. (2001 ).

Experimental

Crystal data

C₂₆H₃₄NSi₂⁺·Cl⁻
M_r = 452.19
Orthorhombic, P 2₁ 2₁ 2₁
a = 10.120 (2) Å
b = 13.289 (3) Å
c = 18.598 (4) Å
V = 2501.3 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 173 (2) K
0.30 × 0.30 × 0.20 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ) T_min = 0.926, T_max = 0.950
45451 measured reflections
4911 independent reflections
4808 reflections with I > 2σ(I)
R_int = 0.077

Refinement

R[F² > 2σ(F²)] = 0.055
wR(F²) = 0.149
S = 1.05
4911 reflections
277 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.34 e Å⁻³
Absolute structure: Flack (1983 ), 2128 Friedel pairs
Flack parameter: 0.08 (10)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H100⋯Cl	1.00 (5)	2.05 (5)	3.031 (3)	166 (4)

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S1600536808028808/wm2191sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808028808/wm2191Isup2.hkl

checkCIF report

Comment top

Functionalized lithiosilanes (Strohmann et al., 2001; Strohmann et al., 2006; Strohmann & Däschlein, 2008a,b) are versatile reagents in organic and organometallic chemistry, e.g. for the nucleophilic introduction of protecting groups, the synthesis of silyl-substituted transition metal complexes or for silicon-based polymers (Lickiss & Smith, 1995; Sekiguchi et al., 2000; Tamao & Kawachi, 1995). Especially highly enantiomerically enriched lithiosilanes are of great interest due to the increased stability of configuration at the stereogenic silicon center compared to the labile alkyllithium compounds. Yet, as the synthetic pathways to functionalized lithiosilanes are extremly limited, only six highly enantiomerically enriched systems are known until today (Colomer & Corriu, 1976; Oestreich et al., 2005; Omote et al., 2000; Sommer & Mason, 1965; Strohmann et al., 2002; Strohmann et al., 2007). Thereby the Si-Si bond cleavage of aryl substituted disilanes with lithium proved to be a potential method for the preperation of these useful compounds.

(S)-1,2-Dimethyl-1,1,2-triphenyl-1-(piperidinomethyl)disilane, (I), is an excellent starting system for the praparation of highly enantiomerically enriched lithiosilanes as it can be synthesised in an e.r. of > 99:1 by means of a racemic resolution with mandelic acid (Strohmann et al., 2002). The reaction with lithium metal results in the selective Si-Si bond cleavage and thus offers a synthetic pathway to highly enantiomerically enriched silicon-chiral di-, tri- and tetrasilanes (Strohmann et al., 2007) and -germanes (Strohmann & Däschlein, 2008b).

Treatment of (I) with HCl yields the title compound, (II), (S)-1,2-Dimethyl-1,1,2-triphenyl-1-(piperidiniummethyl)disilane chloride, as a crystalline solid. The determination of the absolute configuration of the stereogenic silicon center gave the same absolute configuration as the mandelic acid adduct published previously (Strohmann et al., 2002).

The asymmetric unit of (II) contains one molecule of the silicon-chiral disilane. Furthermore, hydrogen bonding between the hydrogen atom of the protonated nitrogen of the piperidino group and the chloride counteranion can be found (Fig. 1). The H···Cl distance (2.05 Å) and the N-H-Cl angle (166.1 °) are in the typical ranges of such hydrogen bonds (Farrugia et al., 2001). With a value of 2.3672 (13) Å, the Si-Si bond length is comparable to other known systems and is slightly larger than the sum of the covalent radii of two silicon atoms (2.33 Å). The silicon-carbon and carbon-nitrogen distances, respectively, are also in the same ranges as in previously published systems. Thereby, the longest silicon-carbon distance can be found between Si1 and C1. Due to the positive charge at the nitrogen in beta-position to Si1, the bond length to C1 is increased to 1.910 (3) Å. The other five Si-C(X) bonds (X = 7, 8, 14, 15, 21) have values between 1.873 (4) and 1.884 (4) Å (average: 1.881 Å) and thus are significantly smaller than the Si1-C1 distance but in very good agreement with the sum of the covalent radii of silicon and carbon (1.88 Å). Considering the Si1-Si2-axis, it is noteworthy to mention that the substituents at the silicon atoms do possess an almost ecliptical arrangement and therefore do not adopt the sterically less hindered staggered conformation.

Related literature top

For related literature on lithiosilanes, see: Lickiss & Smith (1995); Sekiguchi et al. (2000); Strohmann et al. (2001, 2006); Strohmann & Däschlein (2008a,b); Tamao & Kawachi (1995). For related literature on enantiomerically enriched lithiosilanes, see: Colomer & Corriu (1976); Oestreich et al. (2005); Omote et al. (2000); Sommer & Mason (1965); Strohmann et al. (2007). For the determination of the absolute configuration of the disilane as the mandelic acid adduct, see: Strohmann et al. (2002). For related literature on hydrochlorides of amines, see: Farrugia et al. (2001).

Experimental top

To the enantiomerically pure (S)-1,2-Dimethyl-1,2,2-triphenyldisilan-1-(piperidinomethyl)disilane, (I), dissolved in Et₂O, one equivalent of etherical HCl solution was added and stored at room temperature for 24 h. After removal of the solvent, a colourless crystalline solid of (II) remained, suitable for single crystal x-ray studies.

¹H-NMR (500.1 MHz, CDCl₃): δ = -4.92 (s, 3H; NCSiSiCH₃), -4.80 (s, 3H; NCSiCH₃), 0.95–1.05, 1.55–1.60 (m, 1H each; NCCCH₂), 1.40–1.50 (m, 2H; NCCH₂), 1.95–2.05, 2.05–2.15 (m, 1H each; NCCH₂), 2.22–2.28, 2.30–2.37 (m, 1H each; NCH₂C), 2.70–2.75, 2.80–2.85 (m, 1H each; SiCH₂), 3.03–3.07, 3.12–3.18 (m, 1H each; NCH₂C),7.15–7.35 (m, 15H; aromat. H).

{¹H}¹³C-NMR (125.8 MHz, CDCl₃): δ = -4.9 (1 C) (NCSiCH₃), -4.8 (1 C) (NCSiSiCH₃), 21.3 (1 C) (NCCCH₂), 22.5, 22.6 (1 C each) (NCCH₂), 49.4 (1 C) (SiCH₂), 55.2, 57.4 (1 C each) (NCH₂C), 128.06, 128.17, 128.37 (2 C each) (all C-m), 129.36, 129.50,129.78 (1 C each) (all C-p), 134.06, 134.64,134.77 (2 C each) (all C-o), 133.74, 133.99,134.46 (1 C each) (all C-i).

{¹H}²⁹Si-NMR (99.4 MHz, CDCl₃): δ = -25.3 (1Si) (NCSi), -23.5 (1Si) (NCSiSi).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. ORTEP plot of the asymmetric unit of (I) with displacement ellipsoids drawn at the 50% probability level. The dashed line indicates the hydrogen bond.

(S)-1,2-Dimethyl-1,1,2-triphenyl-2-(4-piperidiniomethyl)disilane chloride top

Crystal data top

C₂₆H₃₄NSi₂⁺·Cl⁻	F(000) = 968
M_r = 452.19	D_x = 1.201 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 999 reflections
a = 10.120 (2) Å	θ = 1.9–26.0°
b = 13.289 (3) Å	µ = 0.26 mm⁻¹
c = 18.598 (4) Å	T = 173 K
V = 2501.3 (9) Å³	Block, colourless
Z = 4	0.30 × 0.30 × 0.20 mm

Data collection top

Bruker SMART APEX CCD diffractometer	4911 independent reflections
Radiation source: fine-focus sealed tube	4808 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.077
ω–scans	θ_max = 26.0°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −12→12
T_min = 0.926, T_max = 0.950	k = −16→16
45451 measured reflections	l = −22→22

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.055	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.149	w = 1/[σ²(F_o²) + (0.0402P)² + 1.4067P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
4911 reflections	Δρ_max = 0.41 e Å⁻³
277 parameters	Δρ_min = −0.34 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 2128 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.08 (10)

Crystal data top

C₂₆H₃₄NSi₂⁺·Cl⁻	V = 2501.3 (9) Å³
M_r = 452.19	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 10.120 (2) Å	µ = 0.26 mm⁻¹
b = 13.289 (3) Å	T = 173 K
c = 18.598 (4) Å	0.30 × 0.30 × 0.20 mm

Data collection top

Bruker SMART APEX CCD diffractometer	4911 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1999)	4808 reflections with I > 2σ(I)
T_min = 0.926, T_max = 0.950	R_int = 0.077
45451 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.055	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.149	Δρ_max = 0.41 e Å⁻³
S = 1.05	Δρ_min = −0.34 e Å⁻³
4911 reflections	Absolute structure: Flack (1983), 2128 Friedel pairs
277 parameters	Absolute structure parameter: 0.08 (10)
0 restraints

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
Cl	−0.09614 (10)	0.04149 (6)	0.25243 (5)	0.0361 (2)
Si1	0.28622 (9)	0.21087 (7)	0.20801 (5)	0.0249 (2)
Si2	0.40619 (9)	0.23973 (7)	0.10071 (5)	0.0276 (2)
N1	0.0148 (3)	0.2532 (2)	0.25691 (15)	0.0246 (5)
C3	−0.2128 (4)	0.2953 (3)	0.2978 (2)	0.0346 (8)
H3B	−0.2411	0.2241	0.2961	0.042*
H3A	−0.2909	0.3378	0.2876	0.042*
C17	0.4393 (5)	0.0299 (3)	−0.0646 (2)	0.0433 (10)
H17	0.5060	0.0075	−0.0968	0.052*
C8	0.3754 (3)	0.2680 (3)	0.28642 (17)	0.0271 (7)
C2	−0.1098 (3)	0.3132 (3)	0.24077 (19)	0.0309 (7)
H2A	−0.0881	0.3858	0.2387	0.037*
H2B	−0.1452	0.2930	0.1933	0.037*
C16	0.4683 (4)	0.1011 (3)	−0.0121 (2)	0.0374 (9)
H16	0.5559	0.1262	−0.0082	0.045*
C6	0.0655 (3)	0.2780 (3)	0.32978 (17)	0.0297 (7)
H6A	0.0922	0.3496	0.3312	0.036*
H6B	0.1446	0.2366	0.3400	0.036*
C1	0.1159 (3)	0.2715 (2)	0.19928 (16)	0.0273 (7)
H1A	0.1290	0.3452	0.1956	0.033*
H1B	0.0773	0.2489	0.1531	0.033*
C11	0.4933 (4)	0.3529 (4)	0.4090 (2)	0.0456 (10)
H11	0.5315	0.3812	0.4510	0.055*
C18	0.3126 (5)	−0.0077 (3)	−0.0696 (2)	0.0435 (10)
H18	0.2926	−0.0565	−0.1054	0.052*
C19	0.2150 (5)	0.0243 (3)	−0.0237 (2)	0.0466 (10)
H19	0.1282	−0.0025	−0.0273	0.056*
C10	0.4387 (4)	0.4145 (3)	0.3574 (2)	0.0386 (9)
H10	0.4416	0.4855	0.3630	0.046*
C21	0.3634 (3)	0.3622 (3)	0.05534 (19)	0.0302 (7)
C24	0.3080 (4)	0.5453 (3)	−0.0126 (2)	0.0411 (9)
H24	0.2899	0.6077	−0.0355	0.049*
C26	0.3724 (4)	0.3723 (3)	−0.0189 (2)	0.0366 (8)
H26	0.3978	0.3157	−0.0469	0.044*
C23	0.2970 (4)	0.5373 (3)	0.0615 (2)	0.0420 (9)
H23	0.2708	0.5938	0.0894	0.050*
C9	0.3793 (4)	0.3723 (3)	0.29742 (19)	0.0314 (7)
H9	0.3400	0.4154	0.2627	0.038*
C14	0.5853 (4)	0.2419 (3)	0.1259 (2)	0.0397 (8)
H14C	0.6392	0.2482	0.0823	0.060*
H14B	0.6081	0.1794	0.1509	0.060*
H14A	0.6024	0.2994	0.1576	0.060*
C7	0.2688 (4)	0.0726 (3)	0.2230 (2)	0.0357 (8)
H7B	0.3567	0.0420	0.2266	0.054*
H7C	0.2209	0.0426	0.1825	0.054*
H7A	0.2198	0.0607	0.2676	0.054*
C4	−0.1613 (4)	0.3193 (3)	0.3725 (2)	0.0394 (9)
H4A	−0.1416	0.3920	0.3762	0.047*
H4B	−0.2293	0.3024	0.4088	0.047*
C22	0.3244 (4)	0.4466 (3)	0.0945 (2)	0.0363 (8)
H22	0.3166	0.4415	0.1452	0.044*
C12	0.4926 (4)	0.2503 (4)	0.3995 (2)	0.0435 (9)
H12	0.5315	0.2080	0.4348	0.052*
C5	−0.0374 (4)	0.2590 (3)	0.38669 (18)	0.0334 (8)
H5A	−0.0012	0.2774	0.4344	0.040*
H5B	−0.0595	0.1864	0.3876	0.040*
C20	0.2446 (4)	0.0968 (3)	0.0282 (2)	0.0368 (9)
H20	0.1770	0.1196	0.0596	0.044*
C15	0.3720 (4)	0.1364 (3)	0.03482 (18)	0.0314 (8)
C13	0.4352 (4)	0.2081 (3)	0.33837 (18)	0.0338 (8)
H13	0.4369	0.1372	0.3321	0.041*
C25	0.3450 (4)	0.4636 (3)	−0.0533 (2)	0.0434 (9)
H25	0.3518	0.4690	−0.1041	0.052*
H100	−0.007 (5)	0.180 (4)	0.254 (3)	0.050 (12)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl	0.0441 (5)	0.0229 (4)	0.0413 (5)	−0.0063 (4)	−0.0004 (4)	−0.0006 (3)
Si1	0.0270 (5)	0.0232 (4)	0.0246 (4)	−0.0006 (4)	0.0003 (4)	−0.0014 (3)
Si2	0.0272 (5)	0.0288 (4)	0.0269 (4)	0.0008 (4)	0.0010 (4)	−0.0027 (4)
N1	0.0219 (13)	0.0218 (13)	0.0300 (13)	−0.0003 (11)	−0.0012 (11)	−0.0007 (11)
C3	0.0275 (17)	0.0338 (18)	0.0425 (19)	0.0043 (15)	−0.0010 (16)	0.0033 (16)
C17	0.059 (3)	0.040 (2)	0.0312 (18)	0.018 (2)	0.0047 (17)	−0.0007 (16)
C8	0.0232 (16)	0.0319 (18)	0.0263 (14)	−0.0005 (13)	0.0004 (13)	−0.0045 (13)
C2	0.0268 (17)	0.0288 (16)	0.0370 (17)	0.0046 (14)	−0.0029 (15)	0.0047 (14)
C16	0.044 (2)	0.0319 (19)	0.036 (2)	0.0022 (16)	0.0021 (17)	0.0010 (15)
C6	0.0299 (18)	0.0297 (17)	0.0296 (15)	−0.0014 (14)	−0.0039 (13)	0.0027 (14)
C1	0.0310 (17)	0.0254 (16)	0.0254 (15)	−0.0010 (13)	0.0006 (13)	0.0002 (12)
C11	0.035 (2)	0.067 (3)	0.034 (2)	0.003 (2)	−0.0007 (17)	−0.0203 (19)
C18	0.066 (3)	0.037 (2)	0.0277 (17)	0.006 (2)	−0.0085 (19)	−0.0083 (15)
C19	0.046 (2)	0.048 (2)	0.046 (2)	0.000 (2)	−0.0119 (19)	−0.0086 (18)
C10	0.030 (2)	0.040 (2)	0.046 (2)	−0.0015 (16)	0.0077 (16)	−0.0142 (17)
C21	0.0263 (18)	0.0330 (17)	0.0314 (17)	−0.0021 (14)	0.0021 (14)	0.0005 (14)
C24	0.038 (2)	0.035 (2)	0.051 (2)	−0.0022 (17)	−0.0056 (17)	0.0141 (18)
C26	0.036 (2)	0.039 (2)	0.0353 (19)	−0.0011 (16)	−0.0011 (16)	−0.0027 (16)
C23	0.044 (2)	0.0252 (17)	0.057 (2)	−0.0022 (17)	0.0085 (19)	0.0011 (17)
C9	0.0306 (19)	0.0304 (17)	0.0333 (17)	−0.0031 (14)	−0.0030 (15)	0.0015 (15)
C14	0.0336 (19)	0.047 (2)	0.0386 (19)	0.0019 (18)	−0.0008 (16)	−0.0016 (17)
C7	0.046 (2)	0.0242 (16)	0.0369 (18)	−0.0006 (16)	0.0047 (16)	0.0003 (14)
C4	0.035 (2)	0.045 (2)	0.0382 (19)	0.0024 (17)	0.0073 (16)	−0.0065 (17)
C22	0.036 (2)	0.0367 (19)	0.0360 (18)	−0.0055 (16)	0.0053 (15)	0.0010 (16)
C12	0.038 (2)	0.061 (3)	0.0323 (18)	0.0150 (19)	−0.0073 (16)	0.0049 (19)
C5	0.0322 (18)	0.0378 (19)	0.0302 (17)	−0.0004 (15)	0.0056 (14)	−0.0009 (15)
C20	0.036 (2)	0.039 (2)	0.0353 (19)	0.0032 (16)	0.0016 (16)	−0.0080 (15)
C15	0.037 (2)	0.0297 (17)	0.0281 (17)	0.0024 (15)	−0.0028 (14)	0.0009 (13)
C13	0.034 (2)	0.0348 (18)	0.0325 (17)	0.0053 (16)	−0.0001 (14)	0.0002 (15)
C25	0.049 (2)	0.044 (2)	0.0368 (19)	−0.0060 (19)	−0.0076 (18)	0.0085 (18)

Geometric parameters (Å, º) top

Cl—H100	2.05 (5)	C18—H18	0.9500
Si1—C7	1.867 (4)	C19—C20	1.397 (6)
Si1—C8	1.876 (3)	C19—H19	0.9500
Si1—C1	1.910 (3)	C10—C9	1.386 (5)
Si1—Si2	2.3672 (13)	C10—H10	0.9500
Si2—C14	1.873 (4)	C21—C26	1.390 (5)
Si2—C15	1.873 (4)	C21—C22	1.393 (5)
Si2—C21	1.884 (4)	C24—C25	1.375 (6)
N1—C6	1.486 (4)	C24—C23	1.388 (6)
N1—C1	1.502 (4)	C24—H24	0.9500
N1—C2	1.521 (4)	C26—C25	1.400 (6)
N1—H100	1.00 (5)	C26—H26	0.9500
C3—C2	1.506 (5)	C23—C22	1.381 (6)
C3—C4	1.518 (5)	C23—H23	0.9500
C3—H3B	0.9900	C9—H9	0.9500
C3—H3A	0.9900	C14—H14C	0.9800
C17—C18	1.379 (7)	C14—H14B	0.9800
C17—C16	1.392 (6)	C14—H14A	0.9800
C17—H17	0.9500	C7—H7B	0.9800
C8—C13	1.391 (5)	C7—H7C	0.9800
C8—C9	1.402 (5)	C7—H7A	0.9800
C2—H2A	0.9900	C4—C5	1.511 (5)
C2—H2B	0.9900	C4—H4A	0.9900
C16—C15	1.389 (5)	C4—H4B	0.9900
C16—H16	0.9500	C22—H22	0.9500
C6—C5	1.506 (5)	C12—C13	1.395 (5)
C6—H6A	0.9900	C12—H12	0.9500
C6—H6B	0.9900	C5—H5A	0.9900
C1—H1A	0.9900	C5—H5B	0.9900
C1—H1B	0.9900	C20—C15	1.398 (5)
C11—C12	1.374 (7)	C20—H20	0.9500
C11—C10	1.377 (6)	C13—H13	0.9500
C11—H11	0.9500	C25—H25	0.9500
C18—C19	1.374 (6)	N1—Cl	3.031 (3)

C7—Si1—C8	109.16 (17)	C11—C10—H10	120.2
C7—Si1—C1	110.05 (17)	C9—C10—H10	120.2
C8—Si1—C1	109.24 (14)	C26—C21—C22	117.4 (3)
C7—Si1—Si2	109.48 (13)	C26—C21—Si2	120.9 (3)
C8—Si1—Si2	110.06 (11)	C22—C21—Si2	121.7 (3)
C1—Si1—Si2	108.84 (10)	C25—C24—C23	120.5 (4)
C14—Si2—C15	110.72 (17)	C25—C24—H24	119.7
C14—Si2—C21	108.73 (17)	C23—C24—H24	119.7
C15—Si2—C21	107.34 (15)	C21—C26—C25	121.6 (4)
C14—Si2—Si1	106.77 (13)	C21—C26—H26	119.2
C15—Si2—Si1	109.76 (12)	C25—C26—H26	119.2
C21—Si2—Si1	113.55 (12)	C22—C23—C24	119.4 (4)
C6—N1—C1	112.3 (2)	C22—C23—H23	120.3
C6—N1—C2	110.5 (3)	C24—C23—H23	120.3
C1—N1—C2	109.8 (2)	C10—C9—C8	122.0 (3)
C6—N1—H100	110 (3)	C10—C9—H9	119.0
C1—N1—H100	105 (3)	C8—C9—H9	119.0
C2—N1—H100	109 (3)	Si2—C14—H14C	109.5
C2—C3—C4	112.0 (3)	Si2—C14—H14B	109.5
C2—C3—H3B	109.2	H14C—C14—H14B	109.5
C4—C3—H3B	109.2	Si2—C14—H14A	109.5
C2—C3—H3A	109.2	H14C—C14—H14A	109.5
C4—C3—H3A	109.2	H14B—C14—H14A	109.5
H3B—C3—H3A	107.9	Si1—C7—H7B	109.5
C18—C17—C16	119.4 (4)	Si1—C7—H7C	109.5
C18—C17—H17	120.3	H7B—C7—H7C	109.5
C16—C17—H17	120.3	Si1—C7—H7A	109.5
C13—C8—C9	116.9 (3)	H7B—C7—H7A	109.5
C13—C8—Si1	121.2 (3)	H7C—C7—H7A	109.5
C9—C8—Si1	121.8 (3)	C5—C4—C3	109.5 (3)
C3—C2—N1	110.6 (3)	C5—C4—H4A	109.8
C3—C2—H2A	109.5	C3—C4—H4A	109.8
N1—C2—H2A	109.5	C5—C4—H4B	109.8
C3—C2—H2B	109.5	C3—C4—H4B	109.8
N1—C2—H2B	109.5	H4A—C4—H4B	108.2
H2A—C2—H2B	108.1	C23—C22—C21	121.9 (4)
C15—C16—C17	121.5 (4)	C23—C22—H22	119.1
C15—C16—H16	119.3	C21—C22—H22	119.1
C17—C16—H16	119.3	C11—C12—C13	120.4 (4)
N1—C6—C5	111.4 (3)	C11—C12—H12	119.8
N1—C6—H6A	109.3	C13—C12—H12	119.8
C5—C6—H6A	109.3	C6—C5—C4	111.2 (3)
N1—C6—H6B	109.3	C6—C5—H5A	109.4
C5—C6—H6B	109.3	C4—C5—H5A	109.4
H6A—C6—H6B	108.0	C6—C5—H5B	109.4
N1—C1—Si1	119.1 (2)	C4—C5—H5B	109.4
N1—C1—H1A	107.5	H5A—C5—H5B	108.0
Si1—C1—H1A	107.5	C19—C20—C15	121.2 (4)
N1—C1—H1B	107.5	C19—C20—H20	119.4
Si1—C1—H1B	107.5	C15—C20—H20	119.4
H1A—C1—H1B	107.0	C16—C15—C20	117.7 (3)
C12—C11—C10	119.9 (4)	C16—C15—Si2	121.9 (3)
C12—C11—H11	120.1	C20—C15—Si2	120.3 (3)
C10—C11—H11	120.1	C8—C13—C12	121.1 (4)
C19—C18—C17	121.0 (4)	C8—C13—H13	119.4
C19—C18—H18	119.5	C12—C13—H13	119.4
C17—C18—H18	119.5	C24—C25—C26	119.1 (4)
C18—C19—C20	119.3 (4)	C24—C25—H25	120.4
C18—C19—H19	120.4	C26—C25—H25	120.4
C20—C19—H19	120.4	N1—H100—Cl	166 (4)
C11—C10—C9	119.6 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H100···Cl	1.00 (5)	2.05 (5)	3.031 (3)	166 (4)

Experimental details

Crystal data
Chemical formula	C₂₆H₃₄NSi₂⁺·Cl⁻
M_r	452.19
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	173
a, b, c (Å)	10.120 (2), 13.289 (3), 18.598 (4)
V (Å³)	2501.3 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.26
Crystal size (mm)	0.30 × 0.30 × 0.20

Data collection
Diffractometer	Bruker SMART APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 1999)
T_min, T_max	0.926, 0.950
No. of measured, independent and observed [I > 2σ(I)] reflections	45451, 4911, 4808
R_int	0.077
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.055, 0.149, 1.05
No. of reflections	4911
No. of parameters	277
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.41, −0.34
Absolute structure	Flack (1983), 2128 Friedel pairs
Absolute structure parameter	0.08 (10)

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).

Selected geometric parameters (Å, º) top

Cl—H100	2.05 (5)	N1—H100	1.00 (5)
Si1—Si2	2.3672 (13)	N1—Cl	3.031 (3)

N1—H100—Cl	166 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H100···Cl	1.00 (5)	2.05 (5)	3.031 (3)	166 (4)

Acknowledgements

This work was supported by the Deutsche Forschungsgemeinschaft. CS and VHG also acknowledge the Fonds der Chemischen Industrie and CD thanks the Studienstiftung des Deutschen Volkes for a doctoral scholarship.

References

Bruker (1999). SADABS and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2001). SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Colomer, E. & Corriu, R. J. P. (1976). J. Chem. Soc. Chem Commun. 5, 176–177. CrossRef Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J., Cross, R. J. & Barley, H. R. L. (2001). Acta Cryst. E57, o992–o993. Web of Science CSD CrossRef IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Lickiss, P. D. & Smith, C. M. (1995). Coord. Chem. Rev. 145, 75–124. CrossRef CAS Google Scholar
Oestreich, M., Auer, G. & Keller, M. (2005). Eur. J. Inorg. Chem. 1, 184–195. Web of Science CSD CrossRef Google Scholar
Omote, M., Tokita, T., Shimizu, Y., Imae, I., Shirakawa, E. & Kawakami, Y. (2000). J. Organomet. Chem. 611, 20–25. Web of Science CrossRef CAS Google Scholar
Sekiguchi, A., Lee, V. Y. & Nanjo, M. (2000). Coord. Chem. Rev. 210, 11–45. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sommer, L. H. & Mason, R. J. (1965). J. Am. Chem. Soc. 87, 1619–1620. CrossRef CAS Web of Science Google Scholar
Strohmann, C. & Däschlein, C. (2008a). Chem. Commun. pp. 2791–2793. Web of Science CSD CrossRef Google Scholar
Strohmann, C. & Däschlein, C. (2008b). Organometallics, 27, 2499–2504. Web of Science CSD CrossRef CAS Google Scholar
Strohmann, C., Däschlein, C. & Auer, D. (2006). J. Am. Chem. Soc. 128, 704–705. Web of Science CSD CrossRef PubMed CAS Google Scholar
Strohmann, C., Däschlein, C., Kellert, M. & Auer, D. (2007). Angew. Chem. Int. Ed. 46, 4780–4782. Web of Science CSD CrossRef CAS Google Scholar
Strohmann, C., Hörnig, J. & Auer, D. (2002). Chem. Commun. pp. 766–767. Web of Science CSD CrossRef Google Scholar
Strohmann, C., Ulbrich, O. & Auer, D. (2001). Eur. J. Inorg. Chem. pp. 1013–1018. CrossRef Google Scholar
Tamao, K. & Kawachi, A. (1995). Adv. Organomet. Chem. 38, 1–58. CrossRef CAS Google Scholar