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The homoleptic and monomeric metal alkyls bis{[di­phenyl(piperidino­methyl)­silyl]­methyl}cadmium, [Cd(C19H24­NSi)2] or [Cd{CH2SiPh2(CH2NC5H10)}2], (I), and bis{[di­phenyl­(piperidino­methyl)­silyl]­methyl}magnesium, [Mg(C19H24NSi)2] or [Mg{CH2SiPh2(CH2NC5H10)}2], (II), (CH2NC5H10 is piperidino­methyl) are isostructural, and the mol­ecules exhibit crystallographically imposed C2 symmetry. The metal centres are located on special positions and, for each structure, half of the mol­ecule is located in the asymmetric unit. The metal centres are intramolecularly coordinated and stabilized by two piperidino­methyl groups (side-arm donation). The Si—C and M—C bonds (M is Cd or Mg) are shortened compared with the corresponding non-metallated compounds, indicating stabilization by the diffuse polarizable Si centres (α effect). The C—M—C angle is 140.53 (12)° in (I) and 123.39 (11)° in (II).

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102011307/gd1214sup1.cif
Contains datablocks global, I, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102011307/gd1214Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102011307/gd1214IIsup3.hkl
Contains datablock II

CCDC references: 193405; 193406

Comment top

We are interested in the synthesis of enantiomerically enriched [(aminomethyl)silylmethyl]metal compounds, bearing metals which are essential for preparative organic and inorganic chemistry. By the principle of side-arm donation, a chiral amine can introduce stereochemical information into the system and fix (stabilize) the metal at the metallated C centre by intramolecular coordination. The synthesis of compounds of this type starts from the corresponding [(aminomethyl)silylmethyl]lithium compounds by reaction with metal halides.

In a pre-study, we synthesized non-chiral bis{[diphenyl(piperidinomethyl)silyl]methyl}metal compounds to study them in the solid state. We obtained two interesting molecules of this type for the metals cadmium, (I), and magnesium, (II), the metal centres being intramolecularly coordinated by two piperidinomethyl groups. Compounds (I) and (II) are isostructural and isomorphous. Through two M—C and two M—N contacts (M is Cd or Mg), a spirocyclic system is obtained, with Mg or Cd in the centre, exhibiting distorted tetrahedral geometry at M. \sch

When compared with similar intramolecularly stabilized structures, both (I) and (II) show rather small C—M—C angles. In comparable structures (Henderson et al., 1986; Khan et al., 1987; Schumann et al., 1998), these angles range from 174 (3) to 166.2 (2)°, whereas in (I), the angle is found to be more than 20° smaller (Table 1). In related Mg compounds, the Cl—Mg—Cl angle ranges from 147.68 (8) to 157.0 (7)° for related structures (Seidel et al., 2001; Henderson et al., 1986); again, this angle is more than 20° smaller in (II) (Table 2).

Another feature of these two compounds, as for other polar [(aminomethyl)silylmethyl]metal compounds, is the length of the Si—C bond between Si and the metallated C centre. Since it is well known that Si centres have a stabilizing effect on α-carbanionic centres (α effect), the Si—C bond length depends on the polarity of the M—C bond. In a related non-metallated (silylmethyl)amine (crystallized as an ammonium salt), the Si—C bond length is 1.914 (9) Å (Strohmann et al., 2002). The values in (I) and (II) (Tables 1 and 2) indicate a much more polar M—C bond in (II).

By the formal replacement of CH2 by SiPh2, the C—Cd—C angle decreases (accompanied by a shorter M—N distance), when (I) is compared with a similar structure reported by Schumann et al. (1998). The same observation is made for the C—Mg—C angle of (II), considering related structures reported by Seidel et al. (2001). Whether these interesting angles are the result of electronic or steric effects emerging from the presence of Si in the present structures still remains to be established (e.g. by computational methods).

Experimental top

A 1.7 M solution of t-BuLi in n-pentane (1.09 ml, 1.86 mmol) was added to a solution of [(methyldiphenylsilyl)methyl]piperidine (550 mg, 1.86 mmol) in n-pentane (4 ml) at 183 K. After warming to room temperature, yellow crystals of {[(lithiomethyl)diphenylsilyl]methyl}piperidine (504 mg, 1.67 mmol, 90%) were isolated. These crystals were dissolved in tetrahydrofuran (THF; 6 ml), and a suspension of CdCl2 or [Mg(thf)4Br2] (0.835 mmol) in THF (2 ml) was added at 183 K. The mixture was allowed to warm to room temperature, the solvent was removed and toluene (5 ml) was added. After removal of the lithium halide, compound (II) was crystallized from toluene and compound (I) from toluene-n-pentane. The crystals of both compounds were mounted at 173 K (N2 stream), using the X-TEMP device (Kottke & Stalke, 1993).

Spectroscopic data for (I): 1H NMR (400.1 MHz, toluene-d8, δ, p.p.m.): -0.06 (s, 2JH,Cd = 61.3 Hz, 4H, CdCH2Si), 1.13 (br, 4H, NCCCH2C), 1.42–1.47 (m, 8H, NCCH2C), 2.28 (br, 12H, SiCH2N, NCH2C), 7.14–7.27 (m, 12H, aromatic H), 7.71–7.73 (m, 8H, aromatic H); {1H}13C NMR (100.6 MHz, toluene-d8, δ, p.p.m.): -11.7 (1JC,Cd = 503.1 Hz, CdCH2Si), 23.8 (NCCCH2C), 25.8 (NCCH2C), 51.6 (SiCH2N), 59.0 (NCH2C), 128.0 (C-meta), 128.8 (C-para), 134.7 (C-ortho), 141.4 (C-ipso); {1H}29Si NMR (59.6 MHz, toluene-d8, δ, p.p.m.): -5.4 (2JSi,Cd = 35.0 Hz).

Spectroscopic data for (II): 1H NMR (300.1 MHz, THF-d8, δ, p.p.m.): -1.05 (s, 4H, MgCH2Si), 1.33–1.37 (m, 4H, NCCCH2C), 1.44–1.49 (m, 8H, NCCH2C), 2.41–2.49 (m, 12H, SiCH2N, NCH2C), 7.54–7.61 (m, 12H, aromatic H), 7.62–7.68 (m, 8H, aromatic H); {1H}13C NMR (75.5 MHz, THF-d8, δ, p.p.m.): -16.5 (MgCH2Si), 24.9 (NCCCH2C), 27.4 (NCCH2C), 50.2 (SiCH2N), 59.6 (NCH2C), 128.0 (C-meta), 128.6 (C-para), 135.4 (C-ortho), 144.1 (C-ipso); {1H}29Si NMR (59.6 MHz, THF-d8, δ, p.p.m.): -9.0.

Computing details top

For both compounds, data collection: EXPOSE in IPDS (Stoe & Cie, 1997); cell refinement: CELL in IPDS; data reduction: INTEGRATE in IPDS; program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 2001); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. A view of the molecule of (I) with 50% probability displacement ellipsoids. H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. A view of the molecule of (II) with 50% probability displacement ellipsoids. H atoms are shown as small spheres of arbitrary radii.
(I) Bis{[diphenyl(piperidinomethyl)silyl]methyl}cadmium top
Crystal data top
[Cd(C19H24NSi)2]F(000) = 1464
Mr = 701.36Dx = 1.351 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 7500 reflections
a = 27.277 (5) Åθ = 2.5–27.0°
b = 6.439 (1) ŵ = 0.73 mm1
c = 19.675 (4) ÅT = 173 K
β = 94.06 (3)°Needle, pale yellow
V = 3447.0 (11) Å30.5 × 0.2 × 0.2 mm
Z = 4
Data collection top
Stoe IPDS
diffractometer
3346 reflections with I > 2σ(I)
ϕ scansRint = 0.057
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1997)
θmax = 27°, θmin = 2.5°
Tmin = 0.810, Tmax = 0.868h = 3434
17317 measured reflectionsk = 88
3736 independent reflectionsl = 2525
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullAll H-atom parameters refined
R[F2 > 2σ(F2)] = 0.039 w = 1/[σ2(Fo2) + (0.0597P)2 + 1.3741P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.103(Δ/σ)max < 0.001
S = 1.04Δρmax = 1.71 e Å3
3736 reflectionsΔρmin = 1.37 e Å3
291 parameters
Crystal data top
[Cd(C19H24NSi)2]V = 3447.0 (11) Å3
Mr = 701.36Z = 4
Monoclinic, C2/cMo Kα radiation
a = 27.277 (5) ŵ = 0.73 mm1
b = 6.439 (1) ÅT = 173 K
c = 19.675 (4) Å0.5 × 0.2 × 0.2 mm
β = 94.06 (3)°
Data collection top
Stoe IPDS
diffractometer
3736 independent reflections
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1997)
3346 reflections with I > 2σ(I)
Tmin = 0.810, Tmax = 0.868Rint = 0.057
17317 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.103All H-atom parameters refined
S = 1.04Δρmax = 1.71 e Å3
3736 reflectionsΔρmin = 1.37 e Å3
291 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cd0.0000.20082 (3)0.250.02384 (11)
Si0.10817 (2)0.29625 (8)0.19135 (3)0.02162 (15)
N0.01251 (7)0.4619 (3)0.15595 (8)0.0225 (4)
C10.07303 (9)0.0853 (3)0.22722 (11)0.0268 (4)
H1A0.0925 (13)0.027 (5)0.2692 (15)0.044 (8)*
H1B0.0581 (15)0.017 (6)0.1971 (18)0.057 (10)*
C20.15832 (8)0.3950 (4)0.25351 (10)0.0258 (4)
C30.17904 (11)0.2656 (5)0.30463 (13)0.0337 (5)
H30.1664 (12)0.135 (5)0.3076 (14)0.029 (7)*
C40.21699 (12)0.3336 (5)0.34974 (14)0.0432 (7)
H40.229 (2)0.242 (7)0.382 (3)0.074 (13)*
C50.23524 (10)0.5322 (5)0.34459 (12)0.0430 (6)
H50.2643 (14)0.582 (6)0.3783 (17)0.051 (9)*
C60.21594 (11)0.6640 (5)0.29477 (14)0.0391 (6)
H60.2288 (18)0.802 (6)0.289 (2)0.057 (12)*
C70.17743 (9)0.5970 (4)0.24989 (12)0.0316 (5)
H70.1645 (14)0.688 (4)0.2185 (17)0.033 (8)*
C80.13775 (9)0.2304 (4)0.10994 (11)0.0265 (5)
C90.16493 (9)0.3816 (4)0.07801 (11)0.0324 (5)
H90.1680 (14)0.513 (6)0.0984 (17)0.052 (9)*
C100.18644 (11)0.3419 (5)0.01775 (13)0.0397 (6)
H100.2032 (14)0.459 (6)0.0049 (17)0.049 (9)*
C110.18124 (12)0.1480 (6)0.01261 (13)0.0455 (7)
H110.1971 (13)0.104 (5)0.0544 (15)0.042 (8)*
C120.15491 (12)0.0043 (6)0.01811 (14)0.0495 (7)
H120.1554 (16)0.151 (6)0.0003 (19)0.056 (10)*
C130.13333 (10)0.0361 (5)0.07916 (13)0.0388 (6)
H130.1174 (15)0.067 (6)0.0999 (18)0.058 (10)*
C140.06472 (8)0.5235 (3)0.16972 (11)0.0247 (4)
H14A0.0651 (11)0.618 (4)0.2095 (13)0.025 (6)*
H14B0.0765 (12)0.597 (5)0.1330 (15)0.037 (7)*
C150.01866 (9)0.6489 (4)0.14769 (12)0.0293 (5)
H15A0.0055 (13)0.736 (5)0.1131 (16)0.035 (8)*
H15B0.0125 (13)0.737 (5)0.1879 (16)0.033 (7)*
C160.07219 (9)0.5945 (5)0.13416 (12)0.0333 (5)
H16A0.089 (2)0.729 (7)0.127 (2)0.072 (13)*
H16B0.0805 (12)0.525 (5)0.1723 (15)0.035 (7)*
C170.08042 (10)0.4572 (5)0.07171 (12)0.0406 (6)
H17A0.1160 (14)0.424 (5)0.0663 (16)0.047 (9)*
H17B0.0733 (15)0.541 (6)0.0307 (18)0.058 (10)*
C180.04619 (12)0.2709 (5)0.07727 (14)0.0407 (6)
H18A0.044 (2)0.194 (8)0.037 (3)0.100 (19)*
H18B0.0570 (15)0.176 (5)0.1129 (18)0.043 (9)*
C190.00679 (10)0.3380 (4)0.09273 (11)0.0300 (5)
H19A0.0274 (14)0.223 (5)0.0960 (16)0.032 (8)*
H19B0.0185 (11)0.416 (5)0.0529 (14)0.033 (7)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cd0.01879 (16)0.02933 (15)0.02379 (14)0.0000.00414 (9)0.000
Si0.0167 (3)0.0267 (3)0.0216 (3)0.0012 (2)0.0020 (2)0.00029 (19)
N0.0178 (9)0.0296 (9)0.0200 (7)0.0006 (7)0.0006 (6)0.0007 (7)
C10.0204 (11)0.0277 (10)0.0330 (10)0.0017 (9)0.0057 (8)0.0021 (9)
C20.0189 (11)0.0357 (11)0.0231 (9)0.0018 (9)0.0029 (8)0.0027 (9)
C30.0285 (14)0.0429 (13)0.0292 (11)0.0006 (11)0.0012 (10)0.0018 (10)
C40.0325 (16)0.0671 (18)0.0289 (11)0.0019 (14)0.0060 (10)0.0046 (12)
C50.0243 (13)0.0721 (19)0.0321 (11)0.0055 (13)0.0011 (9)0.0133 (12)
C60.0310 (15)0.0481 (14)0.0387 (13)0.0085 (12)0.0064 (11)0.0110 (12)
C70.0243 (12)0.0392 (12)0.0311 (10)0.0041 (10)0.0006 (9)0.0015 (10)
C80.0186 (12)0.0392 (12)0.0215 (9)0.0016 (9)0.0003 (8)0.0005 (9)
C90.0272 (13)0.0404 (13)0.0303 (10)0.0026 (11)0.0071 (9)0.0037 (10)
C100.0277 (14)0.0602 (16)0.0319 (11)0.0065 (13)0.0062 (10)0.0103 (12)
C110.0341 (16)0.0777 (19)0.0251 (10)0.0083 (15)0.0045 (10)0.0057 (13)
C120.0406 (17)0.067 (2)0.0422 (13)0.0055 (15)0.0077 (11)0.0252 (14)
C130.0311 (14)0.0480 (14)0.0381 (12)0.0063 (12)0.0075 (10)0.0108 (12)
C140.0201 (11)0.0266 (10)0.0275 (9)0.0016 (9)0.0011 (8)0.0034 (8)
C150.0256 (12)0.0325 (11)0.0296 (10)0.0060 (10)0.0007 (9)0.0067 (10)
C160.0231 (12)0.0478 (14)0.0288 (10)0.0048 (11)0.0009 (8)0.0039 (10)
C170.0239 (13)0.0682 (18)0.0286 (10)0.0008 (12)0.0055 (9)0.0007 (12)
C180.0324 (16)0.0588 (17)0.0297 (12)0.0033 (13)0.0055 (10)0.0116 (12)
C190.0260 (13)0.0428 (12)0.0209 (9)0.0021 (11)0.0001 (8)0.0037 (9)
Geometric parameters (Å, º) top
Cd—C1i2.202 (2)C9—C101.383 (3)
Cd—C12.202 (2)C9—H90.94 (4)
Cd—Ni2.5409 (17)C10—C111.387 (5)
Cd—N2.5409 (17)C10—H101.00 (4)
Si—C11.832 (2)C11—C121.380 (5)
Si—C21.880 (2)C11—H111.00 (3)
Si—C81.892 (2)C12—C131.399 (3)
Si—C141.912 (2)C12—H121.01 (4)
N—C151.476 (3)C13—H130.91 (4)
N—C191.477 (3)C14—H14A0.99 (3)
N—C141.485 (3)C14—H14B0.94 (3)
C1—H1A1.02 (3)C15—C161.507 (4)
C1—H1B0.96 (4)C15—H15A0.97 (3)
C2—C31.395 (3)C15—H15B0.98 (3)
C2—C71.404 (3)C16—C171.517 (4)
C3—C41.386 (4)C16—H16A0.98 (5)
C3—H30.91 (3)C16—H16B0.91 (3)
C4—C51.379 (5)C17—C181.519 (4)
C4—H40.92 (5)C17—H17A0.99 (4)
C5—C61.373 (4)C17—H17B1.00 (4)
C5—H51.05 (4)C18—C191.518 (4)
C6—C71.392 (4)C18—H18A0.95 (6)
C6—H60.97 (4)C18—H18B0.99 (3)
C7—H70.91 (3)C19—H19A0.93 (3)
C8—C131.391 (4)C19—H19B1.00 (3)
C8—C91.400 (4)
C1i—Cd—C1140.53 (12)C9—C10—C11119.9 (3)
C1i—Cd—Ni84.56 (7)C9—C10—H10118.5 (19)
C1—Cd—Ni122.80 (8)C11—C10—H10121.4 (19)
C1i—Cd—N122.80 (8)C12—C11—C10119.4 (2)
C1—Cd—N84.56 (7)C12—C11—H11115 (2)
Ni—Cd—N97.15 (8)C10—C11—H11125 (2)
C1—Si—C2112.11 (11)C11—C12—C13120.5 (3)
C1—Si—C8115.22 (11)C11—C12—H12119 (2)
C2—Si—C8107.00 (10)C13—C12—H12120 (2)
C1—Si—C14108.67 (10)C8—C13—C12120.8 (3)
C2—Si—C14107.26 (10)C8—C13—H13120 (2)
C8—Si—C14106.14 (10)C12—C13—H13120 (2)
C15—N—C19108.79 (18)N—C14—Si114.04 (15)
C15—N—C14109.85 (18)N—C14—H14A105.3 (17)
C19—N—C14109.93 (17)Si—C14—H14A108.7 (16)
C15—N—Cd120.92 (13)N—C14—H14B111.7 (19)
C19—N—Cd104.15 (14)Si—C14—H14B108.6 (19)
C14—N—Cd102.74 (12)H14A—C14—H14B108 (2)
Si—C1—Cd109.49 (11)N—C15—C16111.9 (2)
Si—C1—H1A109.1 (19)N—C15—H15A108 (2)
Cd—C1—H1A112.6 (18)C16—C15—H15A114 (2)
Si—C1—H1B119 (2)N—C15—H15B109 (2)
Cd—C1—H1B90 (2)C16—C15—H15B113 (2)
H1A—C1—H1B115 (3)H15A—C15—H15B101 (3)
C3—C2—C7117.2 (2)C15—C16—C17111.4 (2)
C3—C2—Si120.40 (19)C15—C16—H16A105 (3)
C7—C2—Si122.40 (18)C17—C16—H16A111 (3)
C4—C3—C2121.3 (3)C15—C16—H16B105 (2)
C4—C3—H3121.1 (19)C17—C16—H16B110.4 (19)
C2—C3—H3117.6 (19)H16A—C16—H16B114 (3)
C5—C4—C3120.2 (3)C16—C17—C18110.3 (2)
C5—C4—H4122 (3)C16—C17—H17A107.5 (18)
C3—C4—H4118 (3)C18—C17—H17A115 (2)
C6—C5—C4120.3 (3)C16—C17—H17B108 (2)
C6—C5—H5120 (2)C18—C17—H17B109 (2)
C4—C5—H5120 (2)H17A—C17—H17B106 (3)
C5—C6—C7119.7 (3)C19—C18—C17111.2 (3)
C5—C6—H6122 (3)C19—C18—H18A102 (4)
C7—C6—H6119 (3)C17—C18—H18A115 (4)
C6—C7—C2121.4 (3)C19—C18—H18B111 (2)
C6—C7—H7118 (2)C17—C18—H18B109 (2)
C2—C7—H7121 (2)H18A—C18—H18B108 (4)
C13—C8—C9117.6 (2)N—C19—C18111.4 (2)
C13—C8—Si122.76 (19)N—C19—H19A110 (2)
C9—C8—Si119.69 (19)C18—C19—H19A110 (2)
C10—C9—C8121.8 (3)N—C19—H19B111.5 (17)
C10—C9—H9120 (2)C18—C19—H19B109.7 (18)
C8—C9—H9118 (2)H19A—C19—H19B103 (3)
Symmetry code: (i) x, y, z+1/2.
(II) Bis{[diphenyl(piperidinomethyl)silyl]methyl}magnesium top
Crystal data top
[Mg(C19H24NSi)2]F(000) = 1320
Mr = 613.27Dx = 1.195 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 6000 reflections
a = 27.215 (5) Åθ = 2.5–26.0°
b = 6.410 (1) ŵ = 0.15 mm1
c = 19.576 (4) ÅT = 173 K
β = 93.38 (3)°Needle, colourless
V = 3409.1 (11) Å30.6 × 0.2 × 0.1 mm
Z = 4
Data collection top
Stoe IPDS
diffractometer
2453 reflections with I > 2σ(I)
ϕ scansRint = 0.059
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1997)
θmax = 26°, θmin = 2.5°
Tmin = 0.905, Tmax = 0.975h = 3333
13184 measured reflectionsk = 77
3223 independent reflectionsl = 2221
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullAll H-atom parameters refined
R[F2 > 2σ(F2)] = 0.044 w = 1/[σ2(Fo2) + (0.076P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.115(Δ/σ)max < 0.001
S = 1.00Δρmax = 0.34 e Å3
3223 reflectionsΔρmin = 0.38 e Å3
291 parameters
Crystal data top
[Mg(C19H24NSi)2]V = 3409.1 (11) Å3
Mr = 613.27Z = 4
Monoclinic, C2/cMo Kα radiation
a = 27.215 (5) ŵ = 0.15 mm1
b = 6.410 (1) ÅT = 173 K
c = 19.576 (4) Å0.6 × 0.2 × 0.1 mm
β = 93.38 (3)°
Data collection top
Stoe IPDS
diffractometer
3223 independent reflections
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1997)
2453 reflections with I > 2σ(I)
Tmin = 0.905, Tmax = 0.975Rint = 0.059
13184 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.115All H-atom parameters refined
S = 1.00Δρmax = 0.34 e Å3
3223 reflectionsΔρmin = 0.38 e Å3
291 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Mg0.0000.26639 (13)0.250.0114 (2)
Si0.106835 (15)0.30101 (8)0.19397 (3)0.01126 (16)
N0.01175 (5)0.4755 (2)0.15982 (8)0.0112 (3)
C10.06862 (6)0.1050 (3)0.23198 (11)0.0151 (4)
H1A0.0849 (8)0.030 (4)0.2727 (13)0.025 (6)*
H1B0.0562 (9)0.004 (4)0.1968 (15)0.038 (7)*
C20.15775 (6)0.3975 (3)0.25555 (10)0.0147 (4)
C30.17808 (7)0.2643 (3)0.30620 (12)0.0219 (5)
H30.1655 (9)0.126 (4)0.3115 (14)0.031 (7)*
C40.21658 (8)0.3272 (4)0.35054 (13)0.0298 (5)
H40.2301 (12)0.234 (5)0.3825 (19)0.055 (9)*
C50.23613 (8)0.5251 (4)0.34560 (13)0.0297 (6)
H50.2619 (9)0.565 (4)0.3729 (14)0.029 (6)*
C60.21694 (7)0.6608 (4)0.29598 (12)0.0257 (5)
H60.2307 (8)0.792 (4)0.2914 (13)0.021 (6)*
C70.17804 (7)0.5977 (3)0.25159 (12)0.0210 (5)
H70.1645 (8)0.701 (4)0.2150 (13)0.019 (6)*
C80.13661 (6)0.2333 (3)0.11173 (11)0.0148 (4)
C90.16501 (7)0.3816 (3)0.07900 (12)0.0209 (5)
H90.1705 (9)0.523 (4)0.0991 (14)0.030 (6)*
C100.18643 (8)0.3375 (4)0.01818 (13)0.0276 (5)
H100.2041 (9)0.443 (4)0.0036 (15)0.038 (7)*
C110.18027 (8)0.1444 (4)0.01198 (13)0.0313 (6)
H110.1941 (10)0.121 (5)0.0557 (16)0.044 (8)*
C120.15285 (8)0.0050 (4)0.01893 (14)0.0350 (6)
H120.1487 (11)0.143 (5)0.0008 (16)0.048 (8)*
C130.13144 (7)0.0390 (4)0.07998 (13)0.0249 (5)
H130.1139 (9)0.070 (5)0.1035 (15)0.038 (7)*
C140.06490 (6)0.5344 (3)0.17079 (11)0.0136 (4)
H14A0.0666 (7)0.634 (3)0.2090 (12)0.012 (5)*
H14B0.0758 (8)0.608 (4)0.1302 (14)0.027 (6)*
C150.01832 (6)0.6682 (3)0.14876 (12)0.0161 (4)
H15A0.0059 (9)0.742 (4)0.1106 (15)0.029 (7)*
H15B0.0123 (7)0.754 (3)0.1895 (13)0.013 (5)*
C160.07239 (7)0.6180 (4)0.13404 (12)0.0205 (5)
H16A0.0909 (8)0.748 (4)0.1266 (13)0.022 (6)*
H16B0.0843 (8)0.558 (4)0.1744 (13)0.016 (5)*
C170.08055 (7)0.4745 (4)0.07273 (13)0.0258 (5)
H17A0.1142 (10)0.434 (4)0.0664 (15)0.039 (7)*
H17B0.0723 (9)0.552 (4)0.0320 (15)0.032 (7)*
C180.04749 (7)0.2839 (4)0.08047 (13)0.0258 (5)
H18A0.0494 (10)0.188 (4)0.0388 (17)0.043 (8)*
H18B0.0595 (10)0.194 (4)0.1184 (16)0.039 (7)*
C190.00582 (7)0.3456 (3)0.09699 (11)0.0184 (4)
H19A0.0251 (8)0.222 (4)0.1017 (12)0.016 (5)*
H19B0.0180 (8)0.429 (4)0.0565 (14)0.028 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mg0.0091 (4)0.0122 (5)0.0131 (5)0.0000.0027 (3)0.000
Si0.0078 (2)0.0117 (3)0.0144 (3)0.00090 (17)0.00148 (18)0.0002 (2)
N0.0100 (7)0.0108 (8)0.0127 (9)0.0000 (5)0.0003 (6)0.0004 (6)
C10.0119 (8)0.0127 (10)0.0209 (12)0.0009 (7)0.0032 (7)0.0005 (8)
C20.0102 (7)0.0181 (10)0.0161 (11)0.0009 (7)0.0036 (7)0.0034 (8)
C30.0180 (9)0.0242 (12)0.0236 (14)0.0008 (8)0.0008 (8)0.0030 (9)
C40.0227 (10)0.0443 (15)0.0214 (14)0.0014 (10)0.0060 (9)0.0054 (11)
C50.0172 (10)0.0484 (15)0.0231 (15)0.0052 (9)0.0023 (9)0.0105 (11)
C60.0187 (9)0.0290 (13)0.0298 (15)0.0086 (8)0.0036 (9)0.0112 (10)
C70.0169 (9)0.0218 (11)0.0243 (13)0.0046 (8)0.0021 (8)0.0002 (9)
C80.0093 (7)0.0192 (10)0.0157 (12)0.0023 (7)0.0016 (7)0.0001 (8)
C90.0184 (9)0.0221 (11)0.0225 (13)0.0021 (8)0.0050 (8)0.0037 (9)
C100.0210 (9)0.0390 (14)0.0236 (14)0.0067 (9)0.0066 (9)0.0086 (10)
C110.0217 (10)0.0550 (16)0.0173 (14)0.0087 (10)0.0026 (9)0.0054 (11)
C120.0275 (11)0.0440 (15)0.0337 (17)0.0014 (10)0.0034 (10)0.0216 (12)
C130.0195 (9)0.0250 (12)0.0307 (14)0.0047 (8)0.0050 (8)0.0075 (10)
C140.0107 (8)0.0134 (10)0.0167 (12)0.0029 (7)0.0019 (7)0.0017 (8)
C150.0148 (9)0.0140 (10)0.0193 (13)0.0028 (7)0.0000 (7)0.0053 (8)
C160.0136 (9)0.0280 (12)0.0198 (13)0.0051 (8)0.0002 (8)0.0043 (9)
C170.0144 (9)0.0431 (14)0.0192 (14)0.0016 (8)0.0056 (8)0.0015 (10)
C180.0222 (10)0.0337 (13)0.0206 (14)0.0018 (9)0.0066 (8)0.0094 (10)
C190.0176 (9)0.0242 (11)0.0133 (12)0.0031 (8)0.0001 (7)0.0047 (8)
Geometric parameters (Å, º) top
Mg—C1i2.1816 (18)C8—C91.403 (3)
Mg—C12.1816 (18)C9—C101.385 (3)
Mg—Ni2.2545 (17)C9—H91.00 (3)
Mg—N2.2545 (17)C10—C111.378 (4)
Mg—Sii3.1752 (8)C10—H100.95 (3)
Mg—Si3.1752 (9)C11—C121.376 (4)
Si—C11.818 (2)C11—H110.97 (3)
Si—C21.886 (2)C12—C131.389 (3)
Si—C81.895 (2)C12—H120.97 (3)
Si—C141.9200 (19)C13—H130.98 (3)
N—C191.486 (3)C14—H14A0.98 (2)
N—C151.490 (2)C14—H14B0.98 (3)
N—C141.498 (2)C15—C161.517 (3)
C1—H1A1.01 (3)C15—H15A0.96 (3)
C1—H1B0.99 (3)C15—H15B0.97 (2)
C2—C31.398 (3)C16—C171.518 (3)
C2—C71.401 (3)C16—H16A0.98 (2)
C3—C41.381 (3)C16—H16B0.95 (3)
C3—H30.96 (3)C17—C181.520 (3)
C4—C51.381 (4)C17—H17A0.95 (3)
C4—H40.92 (3)C17—H17B0.98 (3)
C5—C61.383 (4)C18—C191.520 (3)
C5—H50.89 (3)C18—H18A1.02 (3)
C6—C71.390 (3)C18—H18B1.01 (3)
C6—H60.93 (2)C19—H19A0.95 (2)
C7—H71.03 (2)C19—H19B1.03 (3)
C8—C131.395 (3)
C1i—Mg—C1123.39 (11)C13—C8—C9116.4 (2)
C1i—Mg—Ni89.60 (7)C13—C8—Si123.08 (16)
C1—Mg—Ni124.81 (7)C9—C8—Si120.50 (16)
C1i—Mg—N124.81 (7)C10—C9—C8121.7 (2)
C1—Mg—N89.60 (7)C10—C9—H9117.6 (15)
Ni—Mg—N107.02 (9)C8—C9—H9120.7 (15)
C1i—Mg—Sii33.62 (5)C11—C10—C9120.3 (2)
C1—Mg—Sii154.02 (6)C11—C10—H10120.2 (17)
Ni—Mg—Sii60.85 (4)C9—C10—H10119.4 (17)
N—Mg—Sii113.83 (4)C10—C11—C12119.5 (2)
C1i—Mg—Si154.02 (6)C10—C11—H11118.2 (18)
C1—Mg—Si33.62 (5)C12—C11—H11122.2 (18)
Ni—Mg—Si113.83 (4)C11—C12—C13120.2 (2)
N—Mg—Si60.85 (4)C11—C12—H12120.8 (18)
Sii—Mg—Si171.99 (3)C13—C12—H12119.0 (19)
C1—Si—C2112.43 (10)C12—C13—C8121.9 (2)
C1—Si—C8118.24 (9)C12—C13—H13120.1 (17)
C2—Si—C8106.45 (8)C8—C13—H13117.9 (17)
C1—Si—C14106.79 (8)N—C14—Si113.14 (12)
C2—Si—C14107.42 (9)N—C14—H14A106.0 (12)
C8—Si—C14104.81 (9)Si—C14—H14A109.0 (12)
C1—Si—Mg41.64 (6)N—C14—H14B109.8 (14)
C2—Si—Mg117.08 (6)Si—C14—H14B111.2 (14)
C8—Si—Mg136.36 (6)H14A—C14—H14B107.5 (19)
C14—Si—Mg65.95 (6)N—C15—C16111.73 (16)
C19—N—C15108.19 (15)N—C15—H15A107.9 (15)
C19—N—C14108.46 (14)C16—C15—H15A109.7 (15)
C15—N—C14109.23 (14)N—C15—H15B106.5 (13)
C19—N—Mg107.54 (12)C16—C15—H15B113.0 (12)
C15—N—Mg120.30 (12)H15A—C15—H15B108 (2)
C14—N—Mg102.59 (11)C15—C16—C17111.94 (17)
Si—C1—Mg104.73 (9)C15—C16—H16A109.3 (13)
Si—C1—H1A114.6 (13)C17—C16—H16A110.4 (15)
Mg—C1—H1A116.1 (13)C15—C16—H16B107.5 (13)
Si—C1—H1B110.3 (16)C17—C16—H16B111.6 (14)
Mg—C1—H1B99.4 (15)H16A—C16—H16B105.8 (19)
H1A—C1—H1B111 (2)C18—C17—C16110.51 (18)
C3—C2—C7117.26 (18)C18—C17—H17A110.6 (17)
C3—C2—Si119.86 (15)C16—C17—H17A111.3 (17)
C7—C2—Si122.83 (16)C18—C17—H17B109.2 (15)
C4—C3—C2121.4 (2)C16—C17—H17B107.8 (16)
C4—C3—H3117.7 (15)H17A—C17—H17B107 (2)
C2—C3—H3120.9 (15)C17—C18—C19111.34 (19)
C5—C4—C3120.4 (2)C17—C18—H18A113.9 (16)
C5—C4—H4120 (2)C19—C18—H18A109.3 (15)
C3—C4—H4120 (2)C17—C18—H18B108.4 (15)
C4—C5—C6119.7 (2)C19—C18—H18B109.8 (16)
C4—C5—H5120.7 (17)H18A—C18—H18B104 (2)
C6—C5—H5119.5 (17)N—C19—C18112.19 (16)
C5—C6—C7119.9 (2)N—C19—H19A110.7 (14)
C5—C6—H6120.0 (15)C18—C19—H19A108.7 (13)
C7—C6—H6120.1 (15)N—C19—H19B109.0 (15)
C6—C7—C2121.3 (2)C18—C19—H19B108.5 (13)
C6—C7—H7118.5 (13)H19A—C19—H19B107.7 (19)
C2—C7—H7120.2 (13)
Symmetry code: (i) x, y, z+1/2.

Experimental details

(I)(II)
Crystal data
Chemical formula[Cd(C19H24NSi)2][Mg(C19H24NSi)2]
Mr701.36613.27
Crystal system, space groupMonoclinic, C2/cMonoclinic, C2/c
Temperature (K)173173
a, b, c (Å)27.277 (5), 6.439 (1), 19.675 (4)27.215 (5), 6.410 (1), 19.576 (4)
β (°) 94.06 (3) 93.38 (3)
V3)3447.0 (11)3409.1 (11)
Z44
Radiation typeMo KαMo Kα
µ (mm1)0.730.15
Crystal size (mm)0.5 × 0.2 × 0.20.6 × 0.2 × 0.1
Data collection
DiffractometerStoe IPDS
diffractometer
Stoe IPDS
diffractometer
Absorption correctionNumerical
(FACEIT in IPDS; Stoe & Cie, 1997)
Numerical
(FACEIT in IPDS; Stoe & Cie, 1997)
Tmin, Tmax0.810, 0.8680.905, 0.975
No. of measured, independent and
observed [I > 2σ(I)] reflections
17317, 3736, 3346 13184, 3223, 2453
Rint0.0570.059
(sin θ/λ)max1)0.6390.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.103, 1.04 0.044, 0.115, 1.00
No. of reflections37363223
No. of parameters291291
H-atom treatmentAll H-atom parameters refinedAll H-atom parameters refined
Δρmax, Δρmin (e Å3)1.71, 1.370.34, 0.38

Computer programs: EXPOSE in IPDS (Stoe & Cie, 1997), CELL in IPDS, INTEGRATE in IPDS, SHELXS86 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 2001), SHELXL97.

Selected geometric parameters (Å, º) for (I) top
Cd—C12.202 (2)Si—C21.880 (2)
Cd—N2.5409 (17)Si—C81.892 (2)
Si—C11.832 (2)Si—C141.912 (2)
C1i—Cd—C1140.53 (12)C1—Cd—N84.56 (7)
C1i—Cd—N122.80 (8)Ni—Cd—N97.15 (8)
Symmetry code: (i) x, y, z+1/2.
Selected geometric parameters (Å, º) for (II) top
Mg—C12.1816 (18)Si—C21.886 (2)
Mg—N2.2545 (17)Si—C81.895 (2)
Si—C11.818 (2)Si—C141.9200 (19)
C1i—Mg—C1123.39 (11)C1i—Mg—N124.81 (7)
C1i—Mg—Ni89.60 (7)Ni—Mg—N107.02 (9)
Symmetry code: (i) x, y, z+1/2.
 

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