Dihydridotetrakis(4-picoline-N)­silicon dibromide chloro­form hexasolvate

The title compound, [SiH₂(C₆H₇N)₄]Br₂·6CHCl₃ or C₂₄H₃₀N₄Si²⁺·2Br^-·6CHCl₃, contains a hexacoordinated Si atom located on a crystallographic centre of inversion. The coordination of the Si atom can be described as a slightly distorted octahedron, with the 4-picoline ligands in the equatorial plane and the two H atoms occupying axial positions. The title compound is isomorphous with its analogue where the Br^- ions are substituted by Cl^- ions.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.054
• wR factor = 0.148
• Data-to-parameter ratio = 18.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_420  Alert C D-H Without Acceptor       Si1    -   H1SI              ?

PLAT_731  Alert C Bond    Calc     1.41(4), Rep   1.400(10) ....       4.00 s.u-Ratio
                     SI1  -H1SI    1.555   1.555

PLAT_731  Alert C Bond    Calc     1.41(4), Rep   1.402(10) ....       4.00 s.u-Ratio
                     SI1  -H1SI    1.555   1.555


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 3 Alert Level C = Please check

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S1. Comment

The title compound, (I), is isomorphous with its analogue where the Cl^- ions are substituted by Br^- ions (Stumpf & Bolte, 2001).

S2. Experimental

The title compound was prepared as described by Faber (2000).

S3. Refinement

All H atoms bonded to C atoms were located by difference Fourier synthesis and refined with fixed individual displacement parameters [U(H) = 1.5U_eq(C_methyl) or U(H) = 1.2U_eq(C)] using a riding model with C—H(aromatic) = 0.95, C—H(methyl) = 0.98 or C—H(tertiary) = 1.00 Å. The methyl groups attached to the aromatic rings were allowed to rotate about their local threefold axis. The H atom bonded to Si was refined isotropically applying a restraint of 1.40 (1) Å to the Si—H distance

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97).

Figures

	Fig. 1. A perspective view of the cation of (I) with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level and H atoms are drawn as small spheres of arbitrary radii.
	Fig. 2. A perspective view of the anion and the solvent molecules of (I) with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level and H atoms are drawn as small spheres of arbitrary radii.

(I)

Crystal data

C24H30N4Si^2+·2Br^−·6CHCl3	Z = 1
Mr = 1278.64	F(000) = 634
Triclinic, P1	Dx = 1.588 Mg m^−3
a = 9.506 (1) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.337 (2) Å	Cell parameters from 8192 reflections
c = 12.960 (2) Å	θ = 1–25°
α = 92.28 (1)°	µ = 2.47 mm^−1
β = 104.06 (1)°	T = 173 K
γ = 98.20 (1)°	Needle, colourless
V = 1337.0 (3) Å^3	0.6 × 0.4 × 0.3 mm

Data collection

Siemens CCD three-circle diffractometer	4721 independent reflections
Radiation source: fine-focus sealed tube	3954 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
ω scans	θmax = 25.0°, θmin = 1.6°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −11→8
Tmin = 0.290, Tmax = 0.477	k = −13→13
15431 measured reflections	l = −15→15

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.148	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0746P)^2 + 3.3546P] where P = (Fo^2 + 2Fc^2)/3
4721 reflections	(Δ/σ)max = 0.020
256 parameters	Δρmax = 1.98 e Å^−3
1 restraint	Δρmin = −0.75 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	0.0000	0.5000	0.0000	0.0456 (5)
H1SI	0.119 (4)	0.484 (5)	−0.043 (4)	0.066 (17)*
N1	0.1122 (4)	0.6524 (3)	0.0707 (3)	0.0427 (9)
C1	0.2366 (5)	0.6997 (4)	0.0467 (4)	0.0394 (10)
H1	0.2686	0.6590	−0.0067	0.047*
C2	0.3194 (5)	0.8046 (4)	0.0965 (4)	0.0423 (11)
H2	0.4061	0.8358	0.0762	0.051*
C3	0.2779 (6)	0.8657 (4)	0.1761 (4)	0.0430 (11)
C4	0.1473 (6)	0.8167 (5)	0.1997 (4)	0.0517 (13)
H4	0.1134	0.8557	0.2531	0.062*
C5	0.0679 (6)	0.7129 (5)	0.1459 (5)	0.0531 (13)
H5	−0.0219	0.6820	0.1621	0.064*
C6	0.3673 (8)	0.9793 (5)	0.2340 (5)	0.0702 (18)
H6A	0.4594	0.9620	0.2795	0.105*
H6B	0.3119	1.0151	0.2783	0.105*
H6C	0.3890	1.0353	0.1822	0.105*
N2	0.0811 (4)	0.4191 (3)	0.1267 (4)	0.0446 (10)
C11	0.0148 (5)	0.4081 (5)	0.2073 (4)	0.0484 (12)
H11	−0.0746	0.4387	0.2011	0.058*
C12	0.0707 (6)	0.3549 (6)	0.2977 (5)	0.0584 (15)
H12	0.0209	0.3501	0.3530	0.070*
C13	0.2009 (6)	0.3075 (6)	0.3090 (5)	0.0617 (16)
C14	0.2665 (6)	0.3168 (5)	0.2249 (5)	0.0604 (16)
H14	0.3541	0.2844	0.2280	0.072*
C15	0.2060 (6)	0.3725 (5)	0.1375 (5)	0.0556 (15)
H15	0.2544	0.3787	0.0814	0.067*
C16	0.2627 (10)	0.2464 (10)	0.4067 (6)	0.112 (3)
H16A	0.2237	0.1608	0.3952	0.168*
H16B	0.2349	0.2809	0.4680	0.168*
H16C	0.3700	0.2576	0.4207	0.168*
Br1	0.62702 (5)	0.26124 (4)	0.19112 (4)	0.04181 (17)
C31	0.6179 (6)	0.5627 (5)	0.2525 (5)	0.0553 (14)
H31	0.6014	0.4735	0.2520	0.066*
Cl2	0.49222 (18)	0.61836 (16)	0.31322 (14)	0.0718 (4)
Cl3	0.5892 (2)	0.60163 (17)	0.11939 (13)	0.0750 (5)
Cl4	0.80040 (17)	0.61693 (15)	0.32598 (14)	0.0706 (4)
C41	0.7651 (7)	0.2137 (6)	0.4654 (5)	0.0657 (16)
H41	0.7420	0.2152	0.3860	0.079*
Cl5	0.8022 (3)	0.3594 (2)	0.5238 (2)	0.1168 (8)
Cl6	0.9219 (2)	0.1459 (2)	0.50962 (17)	0.1009 (7)
Cl7	0.6168 (2)	0.1328 (2)	0.50171 (17)	0.1016 (7)
C51	0.7942 (6)	0.0162 (5)	0.1363 (4)	0.0553 (14)
H51	0.7347	0.0819	0.1384	0.066*
Cl8	0.8133 (3)	−0.0525 (3)	0.25644 (15)	0.1126 (9)
Cl9	0.96476 (18)	0.07808 (15)	0.11516 (19)	0.0869 (6)
Cl10	0.69904 (19)	−0.08931 (13)	0.03056 (13)	0.0665 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0434 (10)	0.0317 (9)	0.0641 (12)	−0.0087 (8)	0.0286 (9)	−0.0077 (8)
N1	0.040 (2)	0.0303 (19)	0.059 (3)	−0.0047 (16)	0.0232 (19)	−0.0030 (18)
C1	0.036 (2)	0.032 (2)	0.055 (3)	0.0036 (19)	0.022 (2)	0.006 (2)
C2	0.034 (2)	0.038 (3)	0.054 (3)	−0.003 (2)	0.013 (2)	0.010 (2)
C3	0.049 (3)	0.030 (2)	0.044 (3)	−0.002 (2)	0.005 (2)	0.006 (2)
C4	0.062 (3)	0.039 (3)	0.058 (3)	0.000 (2)	0.027 (3)	−0.007 (2)
C5	0.047 (3)	0.049 (3)	0.069 (3)	−0.006 (2)	0.034 (3)	−0.007 (3)
C6	0.085 (5)	0.051 (3)	0.058 (4)	−0.025 (3)	0.009 (3)	−0.003 (3)
N2	0.039 (2)	0.029 (2)	0.066 (3)	−0.0087 (16)	0.025 (2)	−0.0111 (18)
C11	0.034 (2)	0.052 (3)	0.063 (3)	0.006 (2)	0.022 (2)	−0.008 (2)
C12	0.050 (3)	0.077 (4)	0.051 (3)	0.019 (3)	0.016 (3)	−0.008 (3)
C13	0.041 (3)	0.077 (4)	0.060 (3)	0.012 (3)	0.001 (3)	−0.020 (3)
C14	0.030 (3)	0.055 (3)	0.094 (5)	−0.001 (2)	0.019 (3)	−0.020 (3)
C15	0.041 (3)	0.043 (3)	0.090 (4)	−0.004 (2)	0.038 (3)	−0.011 (3)
C16	0.090 (6)	0.174 (9)	0.071 (5)	0.074 (6)	−0.009 (4)	−0.011 (5)
Br1	0.0402 (3)	0.0343 (3)	0.0558 (3)	0.00449 (19)	0.0228 (2)	−0.00141 (19)
C31	0.053 (3)	0.045 (3)	0.067 (4)	0.005 (2)	0.017 (3)	−0.009 (3)
Cl2	0.0631 (9)	0.0792 (11)	0.0768 (10)	0.0119 (8)	0.0273 (8)	−0.0116 (8)
Cl3	0.0831 (11)	0.0857 (12)	0.0646 (9)	0.0302 (9)	0.0246 (8)	0.0048 (8)
Cl4	0.0504 (8)	0.0731 (10)	0.0827 (11)	0.0020 (7)	0.0139 (7)	−0.0174 (8)
C41	0.058 (4)	0.072 (4)	0.060 (4)	−0.001 (3)	0.006 (3)	0.007 (3)
Cl5	0.155 (2)	0.0711 (13)	0.1175 (18)	0.0053 (14)	0.0301 (16)	−0.0071 (12)
Cl6	0.0768 (12)	0.1359 (19)	0.0813 (12)	0.0357 (12)	−0.0038 (10)	−0.0143 (12)
Cl7	0.0639 (11)	0.1295 (18)	0.0934 (14)	−0.0177 (11)	−0.0007 (10)	0.0397 (13)
C51	0.062 (3)	0.049 (3)	0.055 (3)	0.022 (3)	0.008 (3)	−0.003 (2)
Cl8	0.143 (2)	0.154 (2)	0.0550 (10)	0.0752 (18)	0.0215 (11)	0.0216 (12)
Cl9	0.0529 (9)	0.0564 (9)	0.1363 (17)	0.0028 (7)	−0.0007 (10)	0.0005 (10)
Cl10	0.0774 (10)	0.0497 (8)	0.0677 (9)	−0.0097 (7)	0.0223 (8)	−0.0042 (7)

Geometric parameters (Å, º)

Si1—H1SI	1.40 (1)	C11—H11	0.950
Si1—N1^i	1.958 (4)	C12—C13	1.396 (8)
Si1—N1	1.958 (4)	C12—H12	0.950
Si1—N2	1.959 (5)	C13—C14	1.382 (9)
Si1—N2^i	1.959 (5)	C13—C16	1.501 (10)
Si1—H1SI	1.402 (10)	C14—C15	1.362 (9)
N1—C1	1.339 (6)	C14—H14	0.950
N1—C5	1.352 (6)	C15—H15	0.950
C1—C2	1.370 (7)	C16—H16A	0.980
C1—H1	0.950	C16—H16B	0.980
C2—C3	1.385 (7)	C16—H16C	0.980
C2—H2	0.950	C31—Cl2	1.754 (6)
C3—C4	1.395 (7)	C31—Cl3	1.764 (6)
C3—C6	1.499 (7)	C31—Cl4	1.772 (6)
C4—C5	1.366 (7)	C31—H31	1.000
C4—H4	0.950	C41—Cl5	1.741 (7)
C5—H5	0.950	C41—Cl7	1.743 (7)
C6—H6A	0.980	C41—Cl6	1.757 (7)
C6—H6B	0.980	C41—H41	1.000
C6—H6C	0.980	C51—Cl8	1.751 (6)
N2—C15	1.346 (7)	C51—Cl10	1.756 (6)
N2—C11	1.347 (6)	C51—Cl9	1.761 (6)
C11—C12	1.365 (8)	C51—H51	1.000
H1SI—Si1—N1^i	91 (2)	C11—N2—Si1	121.4 (4)
H1SI—Si1—N1	89 (2)	N2—C11—C12	122.7 (5)
N1^i—Si1—N1	180.00 (14)	N2—C11—H11	118.6
H1SI—Si1—N2	91 (2)	C12—C11—H11	118.6
N1^i—Si1—N2	90.21 (17)	C11—C12—C13	120.2 (5)
N1—Si1—N2	89.79 (17)	C11—C12—H12	119.9
H1SI—Si1—N2^i	89 (2)	C13—C12—H12	119.9
N1^i—Si1—N2^i	89.79 (17)	C14—C13—C12	116.6 (6)
N1—Si1—N2^i	90.22 (17)	C14—C13—C16	122.2 (6)
N2—Si1—N2^i	180.0	C12—C13—C16	121.1 (6)
H1SI—Si1—H1SI	0 (6)	C15—C14—C13	120.2 (5)
N1^i—Si1—H1SI	91 (2)	C15—C14—H14	119.9
N1—Si1—H1SI	89 (2)	C13—C14—H14	119.9
N2—Si1—H1SI	91 (2)	N2—C15—C14	123.3 (5)
N2^i—Si1—H1SI	89 (2)	N2—C15—H15	118.4
C1—N1—C5	117.7 (4)	C14—C15—H15	118.4
C1—N1—Si1	121.0 (3)	C13—C16—H16A	109.5
C5—N1—Si1	121.4 (3)	C13—C16—H16B	109.5
N1—C1—C2	122.4 (4)	H16A—C16—H16B	109.5
N1—C1—H1	118.8	C13—C16—H16C	109.5
C2—C1—H1	118.8	H16A—C16—H16C	109.5
C1—C2—C3	120.6 (4)	H16B—C16—H16C	109.5
C1—C2—H2	119.7	Cl2—C31—Cl3	110.3 (3)
C3—C2—H2	119.7	Cl2—C31—Cl4	110.4 (3)
C2—C3—C4	116.7 (4)	Cl3—C31—Cl4	110.9 (3)
C2—C3—C6	122.2 (5)	Cl2—C31—H31	108.4
C4—C3—C6	121.1 (5)	Cl3—C31—H31	108.4
C5—C4—C3	120.1 (5)	Cl4—C31—H31	108.4
C5—C4—H4	120.0	Cl5—C41—Cl7	110.5 (4)
C3—C4—H4	120.0	Cl5—C41—Cl6	108.3 (3)
N1—C5—C4	122.5 (5)	Cl7—C41—Cl6	109.6 (4)
N1—C5—H5	118.7	Cl5—C41—H41	109.5
C4—C5—H5	118.7	Cl7—C41—H41	109.5
C3—C6—H6A	109.5	Cl6—C41—H41	109.5
C3—C6—H6B	109.5	Cl8—C51—Cl10	109.0 (3)
H6A—C6—H6B	109.5	Cl8—C51—Cl9	112.3 (3)
C3—C6—H6C	109.5	Cl10—C51—Cl9	110.0 (3)
H6A—C6—H6C	109.5	Cl8—C51—H51	108.5
H6B—C6—H6C	109.5	Cl10—C51—H51	108.5
C15—N2—C11	116.9 (5)	Cl9—C51—H51	108.5
C15—N2—Si1	121.7 (4)
H1SI—Si1—N1—C1	10 (2)	H1SI—Si1—N2—C15	−2 (2)
N2—Si1—N1—C1	101.7 (4)	N1^i—Si1—N2—C15	89.3 (4)
N2^i—Si1—N1—C1	−78.3 (4)	N1—Si1—N2—C15	−90.7 (4)
H1SI—Si1—N1—C5	−169 (2)	H1SI—Si1—N2—C11	177 (2)
N2—Si1—N1—C5	−77.6 (4)	N1^i—Si1—N2—C11	−91.1 (4)
N2^i—Si1—N1—C5	102.4 (4)	N1—Si1—N2—C11	88.9 (4)
C5—N1—C1—C2	0.9 (7)	C15—N2—C11—C12	1.3 (7)
Si1—N1—C1—C2	−178.4 (4)	Si1—N2—C11—C12	−178.3 (4)
N1—C1—C2—C3	1.1 (7)	N2—C11—C12—C13	−0.9 (9)
C1—C2—C3—C4	−1.9 (7)	C11—C12—C13—C14	−0.5 (9)
C1—C2—C3—C6	178.7 (5)	C11—C12—C13—C16	−178.8 (7)
C2—C3—C4—C5	0.7 (8)	C12—C13—C14—C15	1.4 (8)
C6—C3—C4—C5	−179.9 (6)	C16—C13—C14—C15	179.6 (7)
C1—N1—C5—C4	−2.2 (8)	C11—N2—C15—C14	−0.4 (7)
Si1—N1—C5—C4	177.2 (5)	Si1—N2—C15—C14	179.2 (4)
C3—C4—C5—N1	1.4 (9)	C13—C14—C15—N2	−1.0 (8)

Symmetry code: (i) −x, −y+1, −z.