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The reaction products of an addition reaction of five different silicon tetrahalides with the aromatic nitro­gen base 4-methyl­pyridine are presented. The following five structures are isomorphous: (I) tetra­chloro­bis(4-methyl­pyridine)­silicon, C12H14­Cl4­N2Si, (II) bromo­tri­chloro­bis(4-methyl­pyridine)­silicon, C12H14­Br­Cl3N2Si, (III) di­bromo­di­chloro­bis(4-methyl­pyridine)­silicon, C12H14­Br2­Cl2N2Si, (IV) tri­bromo­chloro­bis(4-methyl­pyridine)­silicon, C12H14Br3­Cl­N2Si, and (V) tetra­bromo­bis(4-methyl­pyridine)­silicon, C12H14Br4N2Si. The mol­ecules of (I) and (V), with D2h symmetry, have crystallographic C2h symmetry, while the molecules of (II), (III) and (IV) have a lower molecular symmetry, but as a result of the disorder of the halogen ligands, they appear to be of the same crystallographic symmetry. The environment around the Si atom can be described as a slightly distorted octahedron with the methyl­pyridine ligands occupying axial positions and the four halogen ligands in the equatorial plane. In spite of the different substitution pattern of the silicon centre, there are only insignificant differences between these five structures.

Supporting information

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Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010000278X/ln1098sup1.cif
Contains datablocks I, II, III, IV, V, global

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Structure factor file (CIF format) https://doi.org/10.1107/S010827010000278X/ln1098Isup2.hkl
Contains datablock I

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Structure factor file (CIF format) https://doi.org/10.1107/S010827010000278X/ln1098IIsup3.hkl
Contains datablock II

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Structure factor file (CIF format) https://doi.org/10.1107/S010827010000278X/ln1098IIIsup4.hkl
Contains datablock III

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Structure factor file (CIF format) https://doi.org/10.1107/S010827010000278X/ln1098IVsup5.hkl
Contains datablock IV

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Structure factor file (CIF format) https://doi.org/10.1107/S010827010000278X/ln1098Vsup6.hkl
Contains datablock V

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Portable Document Format (PDF) file https://doi.org/10.1107/S010827010000278X/ln1098sup7.pdf
Supplementary material

CCDC references: 145555; 145556; 145557; 145558; 145559

Comment top

In recent years the extension of the coordination sphere of silicon in complexes with organic nitrogen bases has been the subject of numerous studies (Bechstein et al., 1990; Chuit et al., 1993; Kane et al., 1998; Hensen et al., 1998; Hensen et al. 2000). Several complexes of silicon halides are already known, but only little is known about adducts of mixed silicon halides, because exchange reactions have to be taken into account. This kind of exchange reaction between silicon tetrahalides at high temperatures and pressures have been described by Forbes & Anderson (1944) and were recently proved (Hensen et al., 2000) at ambient conditions. Furthermore, it was presumed (Wannagat et al., 1954) that pyridine or comparable ligands catalyze halogen exchange reactions of silicon halides. This would mean that during the reaction of mixed silicon halides with nitrogen bases not only the Lewis acid-base reaction, but also base-catalyzed dismutations have to be taken into account (Hass & Bechstein, 1981; Bassindale et al., 1995; Kost et al., 1995; Herzog et al., 1996; Boudjouk et al., 1998). We present in this work the first crystal structures of complexes in which the silicon centre carries different halogen ligands. \sch

All five compounds form isomorphous crystals and the cell parameters show only minor differences. However, the following trends are noticeable: in the line from SiCl4 to SiBr4 the c axis is shorter, whereas the a and the b axis are longer.

Compounds (I) and (V) belong to the symmetry point group C2 h (deviating only slightly from molecular D2 h symmetry). (II), (III) and (IV) are of lower molecular symmetry, but as a result of the disorder of the halogen ligands, they display the same crystallographic symmetry as (I) and (V). The Si atom is located on a special position of site symmetry 2/m and the picoline moieties lie on a crystallographic mirror plane. Only the halogen ligands and two H atoms of each methyl group occupy a general position. The silicon centre appears in a nearly ideal octahedral environment, where the two picoline ligands occupy axial positions and the four halogen ligands lie in the equatorial plane. There are only minor deviations from the perfect octahedral coordination. The planes of the methylpyridine rings bisect the Hal-Si-Hal angle almost exactly. As a result of the crystallographic symmetry the N—Si—N bond angles and the Hal-Si-Hal bond angles of opposite halogen atoms are exactly 180°. The remaining bond angles at Si differ only insignificantly from 90°. In spite of the different substitution pattern of the silicon centre, comparable geometric parameters are nearly identical in all five structures: the mean value of the Si—N bond length is 1.980 (4) Å. The C—N—C angle [mean value is 117.6 (1)°] is not affected by the different substitution pattern of the silicon centre, either. The crystallographic symmetry requires that there is only a quarter of the molecule in the asymmetric unit. As a result of that, the halogen atoms in (II), (III) and (IV) are disordered and they cannot be distinguished (see experimental section).

The molecules crystallize in planes perpendicular to the crystallographic a axis. The distance between these planes is a/2. A view onto these planes demonstrates (Fig. 4), that the aromatic residues are nearly perfectly stacked and the Si-Hal4 moieties fill the remaining gaps.

The structures presented in this paper are isostructural with trans-tetrachlorobis(4-methylpyridine)titanium (Hensen et al., 1999). The presence of an aromatic base during the reaction to synthesize these compounds did not considerably stimulate the halogen exchange, a fact that has already been observed (Hensen et al., 2000). As a result of that, no dismutation could be detected and each of the reaction products could be recrystallized. This result could also be attributed to the high dilution of the substance in the solvent and the fact that the complexes are extremely poorly soluble.

Experimental top

To the respective silicon halide (5 mmol) in chloroform (25 ml) 4-picoline was added and the reaction was monitored by measuring the temperature. After approximately 3 h, the precipitated solid was isolated, washed and dried. Crystals of (V) were obtained by heating the powder in an evacuated glas ampul for 2 h to 500 K, then for 5 h to 445 K and cooling down the sample to room temperature within 4 h. (I) to (IV) were dissolved in hot chloroform and crystals appeared within 10 to 15 h at room temperature. Elemental analyses: (II), C12H14BrCl3Si: calculated: C 36.0, H 3.5, Br 19.9, Cl 26.5, N 7.0%; found: C 36.3, H 3.7, Br 18.9, Cl 25.7, N 7.0%; (III), C12H14Br2Cl2Si: calculated: C 32.4, H 3.2, Br 35.9, Cl 15.9, N 6.3%; found: C 33.0, H 3.3, Br 36.3, Cl 16.1, N 6.3%; (IV), C12H14Br3ClSi: calculated: C 30.9, H 3.4, Br 47.5, Cl 7.0, N 5.6%; found: C 30.1, H 3.4, Br 48.8, Cl 6.1, N 5.8%.

Refinement top

All H atoms were initially located by difference Fourier synthesis. Subsequently their positions were idealized and constrained to ride on their parent atoms with C—H(aromatic) = 0.95 and CH(methyl = 0.98 Å, and fixed individual displacement parameters [U(H) = 1.2Ueq(Caromatic) or U(H) = 1.5Ueq(Cmethyl)]. The hydrogen atoms of the methyl groups are disordered. Two orientations differing by a 60° rotation about the Caromatic—Cmethyl bond could be identified.

Due to the crystallographic symmetry of these structures, the halogen atoms of (II), (III) and (IV) are disordered. The resolution of the data did not allow for distinguishing two distinct positions for Cl and Br. Only one peak was found in the respective difference maps. Thus, Br and Cl were refined with a site occupation factor fixed to the appropriate value (according to the elemental analyses) and a restrained bond length of 2.383 (1) Å and 2.203 (1) Å for Si—Br and Si—Cl, respectively. A search in the Cambridge Crystallographic Database (Version 5.18, October 1999; Allen & Kennard, 1993) for the fragment SiN2X4 (X = any group 7 A element) yielded only one comparable structure: tetrachlorodipyridylsilane (Bechstein et al., 1990) which was measured at room temperature. Thus, we employed the values found in (I) and (V) as restraints for the Si—Cl and Si—Br lengths. For (II) the anisotropic displacement parameters of Cl and Br were restrained to have the same Uij components with an effective standard deviation of 0.001.

Computing details top

For all compounds, 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, 1991).

Figures top
[Figure 1] Fig. 1. Perspective view of (I) with the atom numbering; only symmetry independent atoms are labelled; displacement ellipsoids are at the 50% probability level.
[Figure 2] Fig. 2. Perspective view of (II) with the atom numbering; only symmetry independent atoms are labelled; displacement ellipsoids are at the 50% probability level. The crystallographic symmetry imposes Br/Cl disorder at the site of each halogen ligand. This figure is also representative of the structures of (III) and (IV).
[Figure 3] Fig. 3. Perspective view of (V) with the atom numbering; only symmetry independent atoms are labelled; displacement ellipsoids are at the 50% probability level.
[Figure 4] Fig. 4. Packing diagram of (I) representative for all five structures; view perpendicular to the b/c plane.
(I) ; top
Crystal data top
C12H14Cl4N2SiF(000) = 364
Mr = 356.14Dx = 1.524 Mg m3
Orthorhombic, PmnaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2Cell parameters from 8192 reflections
a = 7.1766 (1) Åθ = 1–25°
b = 7.8911 (1) ŵ = 0.83 mm1
c = 13.7036 (1) ÅT = 173 K
V = 776.05 (2) Å3Block, colourless
Z = 20.60 × 0.40 × 0.40 mm
Data collection top
Siemens CCD three-circle
diffractometer
853 independent reflections
Radiation source: fine-focus sealed tube815 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.019
ω scansθmax = 26.3°, θmin = 2.6°
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
h = 88
Tmin = 0.637, Tmax = 0.733k = 99
10172 measured reflectionsl = 1616
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.058H atoms treated by a mixture of independent and constrained refinement
S = 1.15 w = 1/[σ2(Fo2) + (0.0314P)2 + 0.2249P]
where P = (Fo2 + 2Fc2)/3
853 reflections(Δ/σ)max < 0.001
56 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.18 e Å3
Crystal data top
C12H14Cl4N2SiV = 776.05 (2) Å3
Mr = 356.14Z = 2
Orthorhombic, PmnaMo Kα radiation
a = 7.1766 (1) ŵ = 0.83 mm1
b = 7.8911 (1) ÅT = 173 K
c = 13.7036 (1) Å0.60 × 0.40 × 0.40 mm
Data collection top
Siemens CCD three-circle
diffractometer
853 independent reflections
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
815 reflections with I > 2σ(I)
Tmin = 0.637, Tmax = 0.733Rint = 0.019
10172 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0200 restraints
wR(F2) = 0.058H atoms treated by a mixture of independent and constrained refinement
S = 1.15Δρmax = 0.26 e Å3
853 reflectionsΔρmin = 0.18 e Å3
56 parameters
Special details top

Experimental. The data collection nominally covered a sphere of reciprocal space, by a combination of seven, for (I), (III), (IV) and (V), and eight, for (II), sets of exposures; each set had a different ϕ angle for the crystal and each exposure covered 0.3° in ω. The crystal-to-detector distance was 4 cm for (II) and (IV), 5 cm for (III) and 6 cm for (I) and (V). Coverage of the unique set for all structures is 100% complete to at least 25.0° in θ. Crystal decay was monitored by repeating the initial frames at the end of data collection and analyzing the duplicate reflections.

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
xyzUiso*/UeqOcc. (<1)
Si10.00000.50000.50000.01946 (16)
Cl10.21877 (5)0.33821 (4)0.43645 (2)0.03014 (14)
N10.00000.64104 (17)0.38019 (10)0.0208 (3)
C20.00000.8127 (2)0.38592 (13)0.0245 (4)
H20.00000.86420.44860.029*
C30.00000.9155 (2)0.30441 (13)0.0263 (4)
H30.00001.03520.31180.032*
C40.00000.8439 (2)0.21074 (13)0.0237 (4)
C410.00000.9519 (2)0.11990 (13)0.0313 (4)
H41A0.00000.87950.06180.047*0.50
H41B0.11061.02480.11950.047*0.50
H41C0.00001.07220.13770.047*0.50
H41D0.10830.92680.08140.047*0.50
C50.00000.6671 (2)0.20496 (13)0.0251 (4)
H50.00000.61290.14300.030*
C60.00000.5706 (2)0.28969 (12)0.0249 (4)
H60.00000.45060.28420.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0231 (3)0.0158 (3)0.0195 (3)0.0000.0000.0019 (2)
Cl10.0340 (2)0.0270 (2)0.0295 (2)0.01011 (12)0.00782 (12)0.00549 (11)
N10.0242 (7)0.0178 (6)0.0205 (7)0.0000.0000.0023 (5)
C20.0307 (9)0.0193 (8)0.0234 (8)0.0000.0000.0003 (6)
C30.0312 (9)0.0185 (8)0.0292 (9)0.0000.0000.0040 (7)
C40.0196 (8)0.0263 (9)0.0253 (9)0.0000.0000.0076 (7)
C410.0337 (10)0.0325 (9)0.0275 (9)0.0000.0000.0114 (8)
C50.0282 (9)0.0264 (9)0.0206 (8)0.0000.0000.0006 (6)
C60.0309 (9)0.0196 (8)0.0242 (8)0.0000.0000.0006 (7)
Geometric parameters (Å, º) top
Si1—N1i1.9835 (13)C3—H30.9500
Si1—N11.9835 (13)C4—C51.397 (2)
Si1—Cl1ii2.2030 (3)C4—C411.509 (2)
Si1—Cl1iii2.2030 (3)C41—H41A0.9800
Si1—Cl1i2.2030 (3)C41—H41B0.9800
Si1—Cl12.2030 (3)C41—H41C0.9800
N1—C21.357 (2)C41—H41D0.9600
N1—C61.359 (2)C5—C61.389 (2)
C2—C31.381 (2)C5—H50.9500
C2—H20.9500C6—H60.9500
C3—C41.403 (3)
N1i—Si1—N1180.000 (1)C2—C3—H3119.9
N1i—Si1—Cl1ii90.12 (3)C4—C3—H3119.9
N1—Si1—Cl1ii89.88 (3)C5—C4—C3117.03 (16)
N1i—Si1—Cl1iii89.88 (3)C5—C4—C41121.17 (17)
N1—Si1—Cl1iii90.12 (3)C3—C4—C41121.80 (15)
Cl1ii—Si1—Cl1iii180.0C4—C41—H41A109.9
N1i—Si1—Cl1i89.88 (3)C4—C41—H41B109.7
N1—Si1—Cl1i90.12 (3)H41A—C41—H41B109.7
Cl1ii—Si1—Cl1i89.098 (18)C4—C41—H41C110.0
Cl1iii—Si1—Cl1i90.902 (18)H41A—C41—H41C140.1
N1i—Si1—Cl190.12 (3)H41B—C41—H41C55.5
N1—Si1—Cl189.88 (3)C4—C41—H41D109.7
Cl1ii—Si1—Cl190.902 (18)H41A—C41—H41D55.5
Cl1iii—Si1—Cl189.098 (18)H41B—C41—H41D57.4
Cl1i—Si1—Cl1179.999 (12)H41C—C41—H41D109.7
C2—N1—C6117.47 (14)C6—C5—C4120.01 (17)
C2—N1—Si1120.81 (12)C6—C5—H5120.0
C6—N1—Si1121.72 (11)C4—C5—H5120.0
N1—C2—C3122.68 (16)N1—C6—C5122.59 (15)
N1—C2—H2118.7N1—C6—H6118.7
C3—C2—H2118.7C5—C6—H6118.7
C2—C3—C4120.22 (15)
N1i—Si1—N1—C20.0 (2)C6—N1—C2—C30.0
Cl1ii—Si1—N1—C2134.549 (9)Si1—N1—C2—C3180.0
Cl1iii—Si1—N1—C245.451 (9)N1—C2—C3—C40.0
Cl1i—Si1—N1—C245.451 (9)C2—C3—C4—C50.0
Cl1—Si1—N1—C2134.548 (9)C2—C3—C4—C41180.0
N1i—Si1—N1—C6180.0 (2)C3—C4—C5—C60.0
Cl1ii—Si1—N1—C645.451 (9)C41—C4—C5—C6180.0
Cl1iii—Si1—N1—C6134.549 (9)C2—N1—C6—C50.0
Cl1i—Si1—N1—C6134.549 (9)Si1—N1—C6—C5180.0
Cl1—Si1—N1—C645.452 (9)C4—C5—C6—N10.0
Symmetry codes: (i) x, y+1, z+1; (ii) x, y, z; (iii) x, y+1, z+1.
(II) ; top
Crystal data top
C12H14BrCl3N2SiF(000) = 400
Mr = 400.60Dx = 1.717 Mg m3
Orthorhombic, PmnaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2Cell parameters from 8192 reflections
a = 7.177 (1) Åθ = 1–25°
b = 7.962 (1) ŵ = 3.24 mm1
c = 13.557 (1) ÅT = 173 K
V = 774.69 (16) Å3Plate, colourless
Z = 20.40 × 0.30 × 0.10 mm
Data collection top
Siemens CCD three-circle
diffractometer
1278 independent reflections
Radiation source: fine-focus sealed tube1051 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.057
ω scansθmax = 30.5°, θmin = 2.6°
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
h = 1010
Tmin = 0.358, Tmax = 0.738k = 1111
24114 measured reflectionsl = 1919
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.111H atoms treated by a mixture of independent and constrained refinement
S = 1.12 w = 1/[σ2(Fo2) + (0.0576P)2 + 0.7835P]
where P = (Fo2 + 2Fc2)/3
1278 reflections(Δ/σ)max < 0.001
65 parametersΔρmax = 0.65 e Å3
8 restraintsΔρmin = 1.14 e Å3
Crystal data top
C12H14BrCl3N2SiV = 774.69 (16) Å3
Mr = 400.60Z = 2
Orthorhombic, PmnaMo Kα radiation
a = 7.177 (1) ŵ = 3.24 mm1
b = 7.962 (1) ÅT = 173 K
c = 13.557 (1) Å0.40 × 0.30 × 0.10 mm
Data collection top
Siemens CCD three-circle
diffractometer
1278 independent reflections
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
1051 reflections with I > 2σ(I)
Tmin = 0.358, Tmax = 0.738Rint = 0.057
24114 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0408 restraints
wR(F2) = 0.111H atoms treated by a mixture of independent and constrained refinement
S = 1.12Δρmax = 0.65 e Å3
1278 reflectionsΔρmin = 1.14 e Å3
65 parameters
Special details top

Experimental. ;

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
xyzUiso*/UeqOcc. (<1)
Br10.7267 (10)0.1751 (10)0.4254 (6)0.0279 (7)0.25
Cl10.7230 (7)0.1548 (8)0.4385 (5)0.0236 (5)0.75
Si10.50000.00000.50000.0172 (3)
N10.50000.1414 (4)0.6195 (2)0.0185 (6)
C20.50000.3104 (5)0.6123 (3)0.0219 (7)
H20.50000.36000.54860.026*
C30.50000.4138 (5)0.6940 (3)0.0234 (8)
H30.50000.53230.68570.028*
C40.50000.3448 (5)0.7886 (3)0.0202 (7)
C410.50000.4528 (6)0.8791 (3)0.0291 (9)
H41A0.50000.56670.86130.044*0.50
H41B0.39750.42230.92000.044*0.50
H41C0.50000.38800.93840.044*0.50
H41D0.39290.52220.87740.044*0.50
C50.50000.1699 (5)0.7956 (3)0.0228 (8)
H50.50000.11740.85850.027*
C60.50000.0735 (5)0.7111 (3)0.0220 (7)
H60.50000.04540.71730.026*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0369 (7)0.0240 (16)0.0227 (19)0.0067 (7)0.0049 (8)0.0017 (11)
Cl10.0324 (5)0.0195 (12)0.0190 (14)0.0103 (6)0.0087 (6)0.0009 (8)
Si10.0221 (7)0.0139 (6)0.0156 (6)0.0000.0000.0020 (5)
N10.0233 (14)0.0164 (13)0.0157 (14)0.0000.0000.0025 (11)
C20.0284 (19)0.0187 (16)0.0187 (17)0.0000.0000.0001 (13)
C30.0308 (19)0.0177 (16)0.0215 (18)0.0000.0000.0038 (14)
C40.0192 (16)0.0222 (17)0.0191 (17)0.0000.0000.0067 (14)
C410.032 (2)0.033 (2)0.0217 (19)0.0000.0000.0109 (16)
C50.0268 (18)0.0249 (18)0.0168 (17)0.0000.0000.0014 (14)
C60.0292 (18)0.0181 (16)0.0187 (17)0.0000.0000.0003 (13)
Geometric parameters (Å, º) top
Br1—Si12.3695 (11)C2—H20.9500
Cl1—Si12.1856 (10)C3—C41.396 (5)
Si1—N11.973 (3)C3—H30.9500
Si1—N1i1.973 (3)C4—C51.396 (5)
Si1—Cl1i2.1855 (10)C4—C411.498 (5)
Si1—Cl1ii2.1855 (10)C41—H41A0.9381
Si1—Cl1iii2.1856 (10)C41—H41B0.9532
Si1—Br1i2.3695 (11)C41—H41C0.9553
Si1—Br1ii2.3695 (11)C41—H41D0.9471
Si1—Br1iii2.3695 (11)C5—C61.380 (5)
N1—C21.349 (5)C5—H50.9500
N1—C61.354 (5)C6—H60.9500
C2—C31.380 (5)
N1—Si1—N1i180.0N1i—Si1—Br1iii89.1 (2)
N1—Si1—Cl1i90.5 (2)Cl1i—Si1—Br1iii89.52 (6)
N1i—Si1—Cl1i89.5 (2)Cl1ii—Si1—Br1iii176.1 (4)
N1—Si1—Cl1ii90.5 (2)Cl1—Si1—Br1iii90.48 (6)
N1i—Si1—Cl1ii89.5 (2)Cl1iii—Si1—Br1iii3.9 (4)
Cl1i—Si1—Cl1ii94.2 (4)Br1i—Si1—Br1iii93.2 (5)
N1—Si1—Cl189.5 (2)Br1ii—Si1—Br1iii179.999 (1)
N1i—Si1—Cl190.5 (2)Br1—Si1—Br1iii86.8 (5)
Cl1i—Si1—Cl1180.0C2—N1—C6117.7 (3)
Cl1ii—Si1—Cl185.8 (4)C2—N1—Si1120.7 (3)
N1—Si1—Cl1iii89.5 (2)C6—N1—Si1121.6 (2)
N1i—Si1—Cl1iii90.5 (2)N1—C2—C3122.5 (4)
Cl1i—Si1—Cl1iii85.8 (4)N1—C2—H2118.7
Cl1ii—Si1—Cl1iii180.0 (3)C3—C2—H2118.7
Cl1—Si1—Cl1iii94.2 (4)C2—C3—C4120.2 (3)
N1—Si1—Br1i89.1 (2)C2—C3—H3119.9
N1i—Si1—Br1i90.9 (2)C4—C3—H3119.9
Cl1i—Si1—Br1i3.9 (4)C3—C4—C5117.1 (3)
Cl1ii—Si1—Br1i90.48 (6)C3—C4—C41121.8 (3)
Cl1—Si1—Br1i176.1 (4)C5—C4—C41121.1 (4)
Cl1iii—Si1—Br1i89.52 (6)C4—C41—H41A110.2
N1—Si1—Br1ii89.1 (2)C4—C41—H41B109.3
N1i—Si1—Br1ii90.9 (2)H41A—C41—H41B113.3
Cl1i—Si1—Br1ii90.48 (6)C4—C41—H41C112.3
Cl1ii—Si1—Br1ii3.9 (4)H41A—C41—H41C137.6
Cl1—Si1—Br1ii89.52 (6)H41B—C41—H41C51.1
Cl1iii—Si1—Br1ii176.1 (4)C4—C41—H41D108.4
Br1i—Si1—Br1ii86.8 (5)H41A—C41—H41D55.2
N1—Si1—Br190.9 (2)H41B—C41—H41D62.3
N1i—Si1—Br189.1 (2)H41C—C41—H41D109.6
Cl1i—Si1—Br1176.1 (4)C6—C5—C4119.9 (4)
Cl1ii—Si1—Br189.52 (6)C6—C5—H5120.0
Cl1—Si1—Br13.9 (4)C4—C5—H5120.0
Cl1iii—Si1—Br190.48 (6)N1—C6—C5122.6 (3)
Br1i—Si1—Br1180.0N1—C6—H6118.7
Br1ii—Si1—Br193.2 (5)C5—C6—H6118.7
N1—Si1—Br1iii90.9 (2)
N1i—Si1—N1—C21 (100)Br1i—Si1—N1—C643.4 (2)
Cl1i—Si1—N1—C2132.91 (19)Br1ii—Si1—N1—C643.4 (2)
Cl1ii—Si1—N1—C2132.91 (19)Br1—Si1—N1—C6136.6 (2)
Cl1—Si1—N1—C247.09 (19)Br1iii—Si1—N1—C6136.6 (2)
Cl1iii—Si1—N1—C247.09 (19)C6—N1—C2—C30.000 (2)
Br1i—Si1—N1—C2136.6 (2)Si1—N1—C2—C3180.000 (1)
Br1ii—Si1—N1—C2136.6 (2)N1—C2—C3—C40.000 (2)
Br1—Si1—N1—C243.4 (2)C2—C3—C4—C50.000 (2)
Br1iii—Si1—N1—C243.4 (2)C2—C3—C4—C41180.000 (2)
N1i—Si1—N1—C6179.4 (5)C3—C4—C5—C60.000 (2)
Cl1i—Si1—N1—C647.09 (19)C41—C4—C5—C6180.000 (2)
Cl1ii—Si1—N1—C647.09 (19)C2—N1—C6—C50.000 (2)
Cl1—Si1—N1—C6132.91 (19)Si1—N1—C6—C5180.000 (1)
Cl1iii—Si1—N1—C6132.91 (19)C4—C5—C6—N10.000 (2)
Symmetry codes: (i) x+1, y, z+1; (ii) x, y, z+1; (iii) x+1, y, z.
(III) ; top
Crystal data top
C12H14Br2Cl2N2SiF(000) = 436
Mr = 445.06Dx = 1.854 Mg m3
Orthorhombic, PmnaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2Cell parameters from 7725 reflections
a = 7.252 (2) Åθ = 1–25°
b = 8.120 (2) ŵ = 5.48 mm1
c = 13.540 (3) ÅT = 173 K
V = 797.3 (3) Å3Block, colourless
Z = 20.35 × 0.30 × 0.12 mm
Data collection top
Siemens CCD three-circle
diffractometer
1110 independent reflections
Radiation source: fine-focus sealed tube969 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
ω scansθmax = 28.7°, θmin = 2.5°
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.162, Tmax = 0.520k = 1010
14499 measured reflectionsl = 1618
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.027H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.063 w = 1/[σ2(Fo2) + (0.0269P)2 + 0.6549P]
where P = (Fo2 + 2Fc2)/3
S = 1.12(Δ/σ)max = 0.005
1110 reflectionsΔρmax = 0.38 e Å3
66 parametersΔρmin = 0.37 e Å3
2 restraintsExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0048 (9)
Crystal data top
C12H14Br2Cl2N2SiV = 797.3 (3) Å3
Mr = 445.06Z = 2
Orthorhombic, PmnaMo Kα radiation
a = 7.252 (2) ŵ = 5.48 mm1
b = 8.120 (2) ÅT = 173 K
c = 13.540 (3) Å0.35 × 0.30 × 0.12 mm
Data collection top
Siemens CCD three-circle
diffractometer
1110 independent reflections
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
969 reflections with I > 2σ(I)
Tmin = 0.162, Tmax = 0.520Rint = 0.042
14499 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0272 restraints
wR(F2) = 0.063H atoms treated by a mixture of independent and constrained refinement
S = 1.12Δρmax = 0.38 e Å3
1110 reflectionsΔρmin = 0.37 e Å3
66 parameters
Special details top

Experimental. ;

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
xyzUiso*/UeqOcc. (<1)
Br10.2298 (6)0.1680 (6)0.4263 (4)0.0274 (4)0.50
Cl10.2237 (13)0.1512 (14)0.4383 (9)0.0247 (8)0.50
Si10.00000.00000.50000.0185 (2)
N10.00000.1419 (3)0.61919 (17)0.0194 (5)
C20.00000.3083 (4)0.6110 (2)0.0234 (6)
H20.00000.35590.54690.028*
C30.00000.4114 (4)0.6923 (2)0.0239 (6)
H30.00000.52740.68330.029*
C40.00000.3450 (4)0.7877 (2)0.0223 (6)
C410.00000.4530 (4)0.8779 (2)0.0308 (7)
H41A0.00000.56690.86020.046*0.50
H41B0.10250.42250.91890.046*0.50
H41C0.00000.38820.93720.046*0.50
H41D0.10710.52240.87630.046*0.50
C50.00000.1736 (4)0.7959 (2)0.0236 (6)
H50.00000.12340.85930.028*
C60.00000.0765 (4)0.7116 (2)0.0224 (6)
H60.00000.03990.71870.027*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0322 (6)0.0237 (9)0.0263 (12)0.0079 (3)0.0068 (5)0.0018 (6)
Cl10.0340 (11)0.0212 (18)0.0189 (18)0.0115 (10)0.0101 (9)0.0018 (13)
Si10.0243 (5)0.0139 (5)0.0173 (5)0.0000.0000.0025 (4)
N10.0248 (12)0.0164 (11)0.0170 (11)0.0000.0000.0023 (9)
C20.0319 (16)0.0171 (13)0.0212 (14)0.0000.0000.0003 (11)
C30.0290 (15)0.0165 (13)0.0263 (15)0.0000.0000.0061 (11)
C40.0205 (13)0.0240 (14)0.0224 (13)0.0000.0000.0073 (12)
C410.0367 (18)0.0312 (17)0.0246 (16)0.0000.0000.0134 (13)
C50.0282 (15)0.0251 (14)0.0176 (14)0.0000.0000.0011 (11)
C60.0303 (15)0.0165 (13)0.0205 (13)0.0000.0000.0008 (11)
Geometric parameters (Å, º) top
Br1—Si12.3734 (8)C2—H20.9500
Cl1—Si12.1994 (11)C3—C41.399 (4)
Si1—N11.983 (2)C3—H30.9500
Si1—N1i1.983 (2)C4—C51.397 (4)
Si1—Cl1i2.1993 (11)C4—C411.504 (4)
Si1—Cl1ii2.1993 (11)C41—H41A0.9555
Si1—Cl1iii2.1994 (11)C41—H41B0.9600
Si1—Br1i2.3734 (8)C41—H41C0.9600
Si1—Br1ii2.3734 (8)C41—H41D0.9600
Si1—Br1iii2.3734 (8)C5—C61.388 (4)
N1—C21.355 (4)C5—H50.9500
N1—C61.359 (4)C6—H60.9500
C2—C31.382 (4)
N1—Si1—N1i180.0N1i—Si1—Br1iii89.54 (15)
N1—Si1—Cl1i90.9 (3)Cl1i—Si1—Br1iii87.8 (2)
N1i—Si1—Cl1i89.1 (3)Cl1ii—Si1—Br1iii176.8 (5)
N1—Si1—Cl1ii90.9 (3)Cl1iii—Si1—Br1iii3.2 (5)
N1i—Si1—Cl1ii89.1 (3)Cl1—Si1—Br1iii92.2 (2)
Cl1i—Si1—Cl1ii95.1 (7)Br1i—Si1—Br1iii90.8 (3)
N1—Si1—Cl1iii89.1 (3)Br1ii—Si1—Br1iii179.999 (1)
N1i—Si1—Cl1iii90.9 (3)Br1—Si1—Br1iii89.2 (3)
Cl1i—Si1—Cl1iii84.9 (7)C2—N1—C6117.7 (2)
Cl1ii—Si1—Cl1iii179.998 (2)C2—N1—Si1120.8 (2)
N1—Si1—Cl189.1 (3)C6—N1—Si1121.47 (19)
N1i—Si1—Cl190.9 (3)N1—C2—C3122.6 (3)
Cl1i—Si1—Cl1179.998 (1)N1—C2—H2118.7
Cl1ii—Si1—Cl184.9 (7)C3—C2—H2118.7
Cl1iii—Si1—Cl195.1 (7)C2—C3—C4120.1 (3)
N1—Si1—Br1i89.54 (15)C2—C3—H3120.0
N1i—Si1—Br1i90.46 (15)C4—C3—H3120.0
Cl1i—Si1—Br1i3.2 (5)C5—C4—C3117.2 (3)
Cl1ii—Si1—Br1i92.2 (2)C5—C4—C41121.1 (3)
Cl1iii—Si1—Br1i87.8 (2)C3—C4—C41121.7 (3)
Cl1—Si1—Br1i176.8 (5)C4—C41—H41A111.1
N1—Si1—Br1ii89.54 (14)C4—C41—H41B108.6
N1i—Si1—Br1ii90.46 (14)H41A—C41—H41B113.3
Cl1i—Si1—Br1ii92.2 (2)C4—C41—H41C111.1
Cl1ii—Si1—Br1ii3.2 (5)H41A—C41—H41C137.8
Cl1iii—Si1—Br1ii176.8 (5)H41B—C41—H41C51.4
Cl1—Si1—Br1ii87.8 (2)C4—C41—H41D108.9
Br1i—Si1—Br1ii89.2 (3)H41A—C41—H41D55.0
N1—Si1—Br190.46 (15)H41B—C41—H41D62.5
N1i—Si1—Br189.54 (14)H41C—C41—H41D110.0
Cl1i—Si1—Br1176.8 (5)C6—C5—C4120.0 (3)
Cl1ii—Si1—Br187.8 (2)C6—C5—H5120.0
Cl1iii—Si1—Br192.2 (2)C4—C5—H5120.0
Cl1—Si1—Br13.2 (5)N1—C6—C5122.4 (3)
Br1i—Si1—Br1180.0N1—C6—H6118.8
Br1ii—Si1—Br190.8 (3)C5—C6—H6118.8
N1—Si1—Br1iii90.46 (14)
N1i—Si1—N1—C20 (100)Br1i—Si1—N1—C644.60 (14)
Cl1i—Si1—N1—C2132.5 (4)Br1ii—Si1—N1—C644.60 (14)
Cl1ii—Si1—N1—C2132.5 (4)Br1—Si1—N1—C6135.40 (14)
Cl1iii—Si1—N1—C247.5 (4)Br1iii—Si1—N1—C6135.40 (14)
Cl1—Si1—N1—C247.5 (4)C6—N1—C2—C30.000 (1)
Br1i—Si1—N1—C2135.40 (14)Si1—N1—C2—C3180.0
Br1ii—Si1—N1—C2135.40 (14)N1—C2—C3—C40.000 (1)
Br1—Si1—N1—C244.60 (14)C2—C3—C4—C50.000 (1)
Br1iii—Si1—N1—C244.60 (14)C2—C3—C4—C41180.000 (1)
N1i—Si1—N1—C6180.0 (4)C3—C4—C5—C60.000 (1)
Cl1i—Si1—N1—C647.5 (4)C41—C4—C5—C6180.000 (1)
Cl1ii—Si1—N1—C647.5 (4)C2—N1—C6—C50.000 (1)
Cl1iii—Si1—N1—C6132.5 (4)Si1—N1—C6—C5180.0
Cl1—Si1—N1—C6132.5 (4)C4—C5—C6—N10.000 (1)
Symmetry codes: (i) x, y, z+1; (ii) x, y, z+1; (iii) x, y, z.
(IV) ; top
Crystal data top
C12H14Br3ClN2SiF(000) = 472
Mr = 489.52Dx = 2.014 Mg m3
Orthorhombic, PmnaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2Cell parameters from 4418 reflections
a = 7.296 (1) Åθ = 1–25°
b = 8.211 (1) ŵ = 7.73 mm1
c = 13.472 (1) ÅT = 173 K
V = 807.07 (16) Å3Block, colourless
Z = 20.25 × 0.15 × 0.10 mm
Data collection top
Siemens CCD three-circle
diffractometer
1005 independent reflections
Radiation source: fine-focus sealed tube823 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
ω scansθmax = 27.5°, θmin = 2.5°
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.224, Tmax = 0.462k = 1010
11697 measured reflectionsl = 1717
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.024H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.052 w = 1/[σ2(Fo2) + (0.0222P)2 + 0.3546P]
where P = (Fo2 + 2Fc2)/3
S = 1.16(Δ/σ)max = 0.001
1005 reflectionsΔρmax = 0.35 e Å3
66 parametersΔρmin = 0.35 e Å3
2 restraintsExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0044 (6)
Crystal data top
C12H14Br3ClN2SiV = 807.07 (16) Å3
Mr = 489.52Z = 2
Orthorhombic, PmnaMo Kα radiation
a = 7.296 (1) ŵ = 7.73 mm1
b = 8.211 (1) ÅT = 173 K
c = 13.472 (1) Å0.25 × 0.15 × 0.10 mm
Data collection top
Siemens CCD three-circle
diffractometer
1005 independent reflections
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
823 reflections with I > 2σ(I)
Tmin = 0.224, Tmax = 0.462Rint = 0.048
11697 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0242 restraints
wR(F2) = 0.052H atoms treated by a mixture of independent and constrained refinement
S = 1.16Δρmax = 0.35 e Å3
1005 reflectionsΔρmin = 0.35 e Å3
66 parameters
Special details top

Experimental. ;

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
xyzUiso*/UeqOcc. (<1)
Br10.7312 (2)0.1639 (3)0.4262 (2)0.0262 (3)0.75
Cl10.7222 (18)0.151 (2)0.4391 (15)0.0301 (19)0.25
Si10.50000.00000.50000.0167 (3)
N10.50000.1418 (3)0.61899 (19)0.0175 (6)
C20.50000.3059 (4)0.6099 (2)0.0213 (7)
H20.50000.35210.54520.026*
C30.50000.4091 (4)0.6909 (2)0.0226 (7)
H30.50000.52370.68130.027*
C40.50000.3451 (4)0.7868 (3)0.0205 (7)
C410.50000.4524 (4)0.8769 (3)0.0293 (8)
H41A0.50000.56600.86080.044*0.50
H41B0.39750.42170.91950.044*0.50
H41C0.50000.38730.93780.044*0.50
H41D0.39290.52160.87690.044*0.50
C50.50000.1763 (4)0.7955 (2)0.0219 (7)
H50.50000.12760.85950.026*
C60.50000.0793 (4)0.7124 (2)0.0202 (7)
H60.50000.03560.72050.024*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0282 (4)0.0239 (4)0.0266 (8)0.0081 (3)0.0074 (3)0.0045 (3)
Cl10.044 (3)0.032 (3)0.014 (3)0.017 (2)0.0137 (17)0.004 (2)
Si10.0211 (6)0.0135 (6)0.0154 (5)0.0000.0000.0028 (5)
N10.0212 (13)0.0152 (14)0.0161 (12)0.0000.0000.0035 (11)
C20.0299 (18)0.0155 (16)0.0184 (15)0.0000.0000.0005 (13)
C30.0286 (18)0.0132 (15)0.0260 (18)0.0000.0000.0044 (14)
C40.0158 (15)0.0222 (17)0.0235 (15)0.0000.0000.0088 (14)
C410.035 (2)0.027 (2)0.0262 (18)0.0000.0000.0124 (15)
C50.0266 (17)0.0229 (17)0.0163 (15)0.0000.0000.0015 (14)
C60.0262 (17)0.0128 (16)0.0218 (15)0.0000.0000.0000 (14)
Geometric parameters (Å, º) top
Br1—Si12.3758 (6)C2—H20.9500
Cl1—Si12.2021 (11)C3—C41.394 (5)
Si1—N1i1.981 (2)C3—H30.9500
Si1—N11.981 (2)C4—C51.391 (4)
Si1—Cl1ii2.2021 (11)C4—C411.500 (5)
Si1—Cl1i2.2022 (11)C41—H41A0.9578
Si1—Cl1iii2.2022 (11)C41—H41B0.9759
Si1—Br1ii2.3758 (6)C41—H41C0.9794
Si1—Br1i2.3758 (6)C41—H41D0.9659
Si1—Br1iii2.3758 (6)C5—C61.374 (5)
N1—C21.353 (4)C5—H50.9500
N1—C61.359 (4)C6—H60.9500
C2—C31.382 (4)
N1i—Si1—N1180.0N1—Si1—Br1iii89.68 (9)
N1i—Si1—Cl191.7 (6)Cl1—Si1—Br1iii87.3 (4)
N1—Si1—Cl188.3 (6)Cl1ii—Si1—Br1iii177.0 (6)
N1i—Si1—Cl1ii91.7 (6)Cl1i—Si1—Br1iii92.7 (4)
N1—Si1—Cl1ii88.3 (6)Cl1iii—Si1—Br1iii3.0 (6)
Cl1—Si1—Cl1ii94.8 (10)Br1ii—Si1—Br1iii180.0
N1i—Si1—Cl1i88.3 (6)Br1—Si1—Br1iii89.53 (11)
N1—Si1—Cl1i91.7 (6)Br1i—Si1—Br1iii90.47 (11)
Cl1—Si1—Cl1i180.0C2—N1—C6117.4 (3)
Cl1ii—Si1—Cl1i85.2 (10)C2—N1—Si1120.8 (2)
N1i—Si1—Cl1iii88.3 (6)C6—N1—Si1121.8 (2)
N1—Si1—Cl1iii91.7 (6)N1—C2—C3122.6 (3)
Cl1—Si1—Cl1iii85.2 (10)N1—C2—H2118.7
Cl1ii—Si1—Cl1iii179.998 (3)C3—C2—H2118.7
Cl1i—Si1—Cl1iii94.8 (10)C2—C3—C4120.1 (3)
N1i—Si1—Br1ii89.68 (9)C2—C3—H3120.0
N1—Si1—Br1ii90.32 (9)C4—C3—H3120.0
Cl1—Si1—Br1ii92.7 (4)C5—C4—C3117.0 (3)
Cl1ii—Si1—Br1ii3.0 (6)C5—C4—C41121.1 (3)
Cl1i—Si1—Br1ii87.3 (4)C3—C4—C41121.9 (3)
Cl1iii—Si1—Br1ii177.0 (6)C4—C41—H41A112.8
N1i—Si1—Br189.68 (9)C4—C41—H41B108.9
N1—Si1—Br190.32 (9)H41A—C41—H41B112.7
Cl1—Si1—Br13.0 (6)C4—C41—H41C111.0
Cl1ii—Si1—Br192.7 (4)H41A—C41—H41C136.2
Cl1i—Si1—Br1177.0 (6)H41B—C41—H41C50.7
Cl1iii—Si1—Br187.3 (4)C4—C41—H41D110.2
Br1ii—Si1—Br190.47 (11)H41A—C41—H41D55.1
N1i—Si1—Br1i90.32 (9)H41B—C41—H41D62.1
N1—Si1—Br1i89.68 (9)H41C—C41—H41D108.7
Cl1—Si1—Br1i177.0 (6)C6—C5—C4120.6 (3)
Cl1ii—Si1—Br1i87.3 (4)C6—C5—H5119.7
Cl1i—Si1—Br1i3.0 (6)C4—C5—H5119.7
Cl1iii—Si1—Br1i92.7 (4)N1—C6—C5122.4 (3)
Br1ii—Si1—Br1i89.53 (11)N1—C6—H6118.8
Br1—Si1—Br1i180.0C5—C6—H6118.8
N1i—Si1—Br1iii90.32 (9)
N1i—Si1—N1—C2179.7 (7)Br1ii—Si1—N1—C6134.76 (5)
Cl1—Si1—N1—C247.4 (5)Br1—Si1—N1—C6134.76 (5)
Cl1ii—Si1—N1—C247.4 (5)Br1i—Si1—N1—C645.24 (5)
Cl1i—Si1—N1—C2132.6 (5)Br1iii—Si1—N1—C645.24 (5)
Cl1iii—Si1—N1—C2132.6 (5)C6—N1—C2—C30.000 (1)
Br1ii—Si1—N1—C245.24 (5)Si1—N1—C2—C3180.000 (1)
Br1—Si1—N1—C245.24 (5)N1—C2—C3—C40.000 (2)
Br1i—Si1—N1—C2134.76 (5)C2—C3—C4—C50.000 (2)
Br1iii—Si1—N1—C2134.76 (5)C2—C3—C4—C41180.000 (1)
N1i—Si1—N1—C60 (100)C3—C4—C5—C60.000 (2)
Cl1—Si1—N1—C6132.6 (5)C41—C4—C5—C6180.000 (1)
Cl1ii—Si1—N1—C6132.6 (5)C2—N1—C6—C50.000 (1)
Cl1i—Si1—N1—C647.4 (5)Si1—N1—C6—C5180.0
Cl1iii—Si1—N1—C647.4 (5)C4—C5—C6—N10.000 (2)
Symmetry codes: (i) x+1, y, z+1; (ii) x+1, y, z; (iii) x, y, z+1.
(V) ; top
Crystal data top
C12H14Br4N2SiF(000) = 508
Mr = 533.98Dx = 2.178 Mg m3
Orthorhombic, PmnaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2Cell parameters from 7725 reflections
a = 7.3298 (2) Åθ = 1–25°
b = 8.2819 (3) ŵ = 9.95 mm1
c = 13.4126 (3) ÅT = 143 K
V = 814.21 (4) Å3Block, colourless
Z = 20.30 × 0.20 × 0.05 mm
Data collection top
Siemens CCD three-circle
diffractometer
907 independent reflections
Radiation source: fine-focus sealed tube728 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.045
ω scansθmax = 26.4°, θmin = 2.9°
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.105, Tmax = 0.609k = 1010
7079 measured reflectionsl = 1416
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.065H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0342P)2 + 0.9192P]
where P = (Fo2 + 2Fc2)/3
907 reflections(Δ/σ)max = 0.001
56 parametersΔρmax = 0.63 e Å3
0 restraintsΔρmin = 0.48 e Å3
Crystal data top
C12H14Br4N2SiV = 814.21 (4) Å3
Mr = 533.98Z = 2
Orthorhombic, PmnaMo Kα radiation
a = 7.3298 (2) ŵ = 9.95 mm1
b = 8.2819 (3) ÅT = 143 K
c = 13.4126 (3) Å0.30 × 0.20 × 0.05 mm
Data collection top
Siemens CCD three-circle
diffractometer
907 independent reflections
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
728 reflections with I > 2σ(I)
Tmin = 0.105, Tmax = 0.609Rint = 0.045
7079 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0280 restraints
wR(F2) = 0.065H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.63 e Å3
907 reflectionsΔρmin = 0.48 e Å3
56 parameters
Special details top

Experimental. ;

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
xyzUiso*/UeqOcc. (<1)
Br10.23257 (4)0.16177 (4)0.42619 (3)0.02330 (15)
Si10.00000.00000.50000.0150 (4)
N10.00000.1415 (5)0.6189 (3)0.0168 (9)
C20.00000.3052 (6)0.6088 (4)0.0176 (10)
H20.00000.35040.54370.021*
C30.00000.4080 (6)0.6901 (4)0.0204 (11)
H30.00000.52150.68000.024*
C40.00000.3460 (6)0.7870 (4)0.0197 (10)
C410.00000.4520 (6)0.8766 (4)0.0264 (12)
H41A0.00000.56680.85980.040*0.50
H41B0.10250.42250.91850.040*0.50
H41C0.00000.38810.93690.040*0.50
H41D0.10710.52240.87590.040*0.50
C50.00000.1782 (6)0.7964 (4)0.0199 (10)
H50.00000.13070.86080.024*
C60.00000.0803 (6)0.7130 (4)0.0191 (10)
H60.00000.03350.72170.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0237 (2)0.0194 (2)0.0268 (2)0.00750 (14)0.00648 (14)0.00455 (15)
Si10.0161 (8)0.0109 (9)0.0181 (9)0.0000.0000.0023 (8)
N10.0179 (19)0.014 (2)0.018 (2)0.0000.0000.0035 (17)
C20.020 (2)0.010 (2)0.022 (3)0.0000.0000.0035 (19)
C30.026 (3)0.010 (2)0.025 (3)0.0000.0000.002 (2)
C40.013 (2)0.020 (3)0.026 (2)0.0000.0000.008 (2)
C410.027 (3)0.026 (3)0.026 (3)0.0000.0000.010 (2)
C50.020 (2)0.023 (3)0.017 (3)0.0000.0000.004 (2)
C60.026 (2)0.012 (2)0.019 (2)0.0000.0000.000 (2)
Geometric parameters (Å, º) top
Br1—Si12.3835 (3)C3—H30.9500
Si1—N11.979 (4)C4—C51.396 (7)
Si1—N1i1.979 (4)C4—C411.488 (7)
Si1—Br1i2.3835 (3)C41—H41A0.9777
Si1—Br1ii2.3835 (3)C41—H41B0.9698
Si1—Br1iii2.3835 (3)C41—H41C0.9657
N1—C61.360 (6)C41—H41D0.9781
N1—C21.363 (6)C5—C61.381 (7)
C2—C31.384 (7)C5—H50.9500
C2—H20.9500C6—H60.9500
C3—C41.397 (7)
N1—Si1—N1i180.0C2—C3—H3119.8
N1—Si1—Br1i89.89 (8)C4—C3—H3119.8
N1i—Si1—Br1i90.11 (8)C5—C4—C3116.7 (5)
N1—Si1—Br1ii89.89 (8)C5—C4—C41121.0 (5)
N1i—Si1—Br1ii90.11 (8)C3—C4—C41122.3 (5)
Br1i—Si1—Br1ii91.320 (17)C4—C41—H41A112.8
N1—Si1—Br1iii90.11 (8)C4—C41—H41B108.6
N1i—Si1—Br1iii89.89 (8)H41A—C41—H41B112.2
Br1i—Si1—Br1iii88.680 (17)C4—C41—H41C110.7
Br1ii—Si1—Br1iii180.0H41A—C41—H41C136.5
N1—Si1—Br190.11 (8)H41B—C41—H41C51.5
N1i—Si1—Br189.89 (8)C4—C41—H41D110.1
Br1i—Si1—Br1180.0H41A—C41—H41D54.4
Br1ii—Si1—Br188.680 (17)H41B—C41—H41D62.2
Br1iii—Si1—Br191.320 (17)H41C—C41—H41D109.5
C6—N1—C2117.6 (4)C6—C5—C4120.8 (5)
C6—N1—Si1121.8 (3)C6—C5—H5119.6
C2—N1—Si1120.6 (3)C4—C5—H5119.6
N1—C2—C3122.2 (5)N1—C6—C5122.2 (4)
N1—C2—H2118.9N1—C6—H6118.9
C3—C2—H2118.9C5—C6—H6118.9
C2—C3—C4120.5 (5)
N1i—Si1—N1—C6180.0 (6)C6—N1—C2—C30.000 (2)
Br1i—Si1—N1—C645.660 (9)Si1—N1—C2—C3180.000 (2)
Br1ii—Si1—N1—C645.660 (9)N1—C2—C3—C40.000 (2)
Br1iii—Si1—N1—C6134.340 (9)C2—C3—C4—C50.000 (2)
Br1—Si1—N1—C6134.340 (9)C2—C3—C4—C41180.000 (2)
N1i—Si1—N1—C20 (100)C3—C4—C5—C60.000 (2)
Br1i—Si1—N1—C2134.340 (9)C41—C4—C5—C6180.000 (2)
Br1ii—Si1—N1—C2134.340 (9)C2—N1—C6—C50.000 (2)
Br1iii—Si1—N1—C245.660 (9)Si1—N1—C6—C5180.000 (1)
Br1—Si1—N1—C245.660 (9)C4—C5—C6—N10.000 (2)
Symmetry codes: (i) x, y, z+1; (ii) x, y, z+1; (iii) x, y, z.

Experimental details

(I)(II)(III)(IV)
Crystal data
Chemical formulaC12H14Cl4N2SiC12H14BrCl3N2SiC12H14Br2Cl2N2SiC12H14Br3ClN2Si
Mr356.14400.60445.06489.52
Crystal system, space groupOrthorhombic, PmnaOrthorhombic, PmnaOrthorhombic, PmnaOrthorhombic, Pmna
Temperature (K)173173173173
a, b, c (Å)7.1766 (1), 7.8911 (1), 13.7036 (1)7.177 (1), 7.962 (1), 13.557 (1)7.252 (2), 8.120 (2), 13.540 (3)7.296 (1), 8.211 (1), 13.472 (1)
V3)776.05 (2)774.69 (16)797.3 (3)807.07 (16)
Z2222
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.833.245.487.73
Crystal size (mm)0.60 × 0.40 × 0.400.40 × 0.30 × 0.100.35 × 0.30 × 0.120.25 × 0.15 × 0.10
Data collection
DiffractometerSiemens CCD three-circle
diffractometer
Siemens CCD three-circle
diffractometer
Siemens CCD three-circle
diffractometer
Siemens CCD three-circle
diffractometer
Absorption correctionEmpirical
(SADABS; Sheldrick, 1996)
Empirical
(SADABS; Sheldrick, 1996)
Empirical
(SADABS; Sheldrick, 1996)
Empirical
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.637, 0.7330.358, 0.7380.162, 0.5200.224, 0.462
No. of measured, independent and
observed [I > 2σ(I)] reflections
10172, 853, 815 24114, 1278, 1051 14499, 1110, 969 11697, 1005, 823
Rint0.0190.0570.0420.048
(sin θ/λ)max1)0.6230.7140.6750.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.020, 0.058, 1.15 0.040, 0.111, 1.12 0.027, 0.063, 1.12 0.024, 0.052, 1.16
No. of reflections853127811101005
No. of parameters56656666
No. of restraints0822
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.26, 0.180.65, 1.140.38, 0.370.35, 0.35


(V)
Crystal data
Chemical formulaC12H14Br4N2Si
Mr533.98
Crystal system, space groupOrthorhombic, Pmna
Temperature (K)143
a, b, c (Å)7.3298 (2), 8.2819 (3), 13.4126 (3)
V3)814.21 (4)
Z2
Radiation typeMo Kα
µ (mm1)9.95
Crystal size (mm)0.30 × 0.20 × 0.05
Data collection
DiffractometerSiemens CCD three-circle
diffractometer
Absorption correctionEmpirical
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.105, 0.609
No. of measured, independent and
observed [I > 2σ(I)] reflections
7079, 907, 728
Rint0.045
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.065, 1.04
No. of reflections907
No. of parameters56
No. of restraints0
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.63, 0.48

Computer programs: SMART (Siemens, 1995), SMART, SAINT (Siemens, 1995), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP (in SHELXTL-Plus, 1991).

Selected geometric parameters (Å, º) for (I) top
Si1—N11.9835 (13)N1—C21.357 (2)
Si1—Cl12.2030 (3)N1—C61.359 (2)
N1—Si1—Cl189.88 (3)C2—N1—C6117.47 (14)
Cl1—Si1—N1—C645.452 (9)
Selected geometric parameters (Å, º) for (II) top
Br1—Si12.3695 (11)Si1—N11.973 (3)
Cl1—Si12.1856 (10)
N1—Si1—Cl189.5 (2)C2—N1—C6117.7 (3)
N1—Si1—Br190.9 (2)
Cl1—Si1—N1—C247.09 (19)Br1—Si1—N1—C243.4 (2)
Selected geometric parameters (Å, º) for (III) top
Br1—Si12.3734 (8)Si1—N11.983 (2)
Cl1—Si12.1994 (11)
N1—Si1—Cl189.1 (3)C2—N1—C6117.7 (2)
N1—Si1—Br190.46 (15)
Cl1—Si1—N1—C247.5 (4)Br1—Si1—N1—C244.60 (14)
Selected geometric parameters (Å, º) for (IV) top
Br1—Si12.3758 (6)Si1—N11.981 (2)
Cl1—Si12.2021 (11)
N1—Si1—Cl188.3 (6)C2—N1—C6117.4 (3)
N1—Si1—Br190.32 (9)
Cl1—Si1—N1—C247.4 (5)Br1—Si1—N1—C245.24 (5)
Selected geometric parameters (Å, º) for (V) top
Br1—Si12.3835 (3)Si1—N11.979 (4)
N1—Si1—Br190.11 (8)C6—N1—C2117.6 (4)
Br1—Si1—N1—C245.660 (9)
 

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