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The compounds tetrakis(trimethylstannyl)germane, Ge(SnMe3)4 (1), and tetrakis(trimethylstannyl)silane, Si(SnMe3)4 (2), have crystal structures with the quasispherical molecules in a closed-packed stacking. At room temperature both structures have the space group P
(Z = 2) with a = 9.94457 (5), b = 14.52927 (8), c = 9.16021 (5) Å, α = 90.53390 (30), β = 111.73080 (30), γ = 90.0049 (4)°, and V = 1229.414 (12) Å3 for (1) and a = 9.92009 (7), b = 14.51029 (11), c = 9.13585 (7) Å, α = 90.4769 (4), β = 111.6724 (4), γ = 89.9877 (6)°, and V = 1222.037 (16) Å3 for (2). The molecules are found to be ordered as a result of steric interactions between neighboring molecules, as shown by analyzing the distances between the atoms. Upon heating, both compounds undergo a first-order phase transition at temperatures Tc = 348 ± 5 K, as characterized by a relative jump of the lattice parameter of ∼16%. At 353 K, both structures have the space group P (Z = 4), with a = 14.2037 (2) Å, and V = 2865.52 (7) Å3 for (1) and a = 14.1346 (2) Å, and V = 2823.90 (7) Å3 for (2). Rietveld refinements were performed for the low-temperature phases measured at T = 295 K [Rwp = 0.0844 for (1), Rwp = 0.0940 for (2)] and for the high-temperature phases measured at T = 353 K [Rwp = 0.0891 for (1), Rwp = 0.0542 for (2)]. The combination of high-resolution X-ray powder diffraction measurements and variable-temperature magic-angle-spinning 13C, 29Si and 119Sn NMR experiments demonstrates low crystallographic and molecular (C1) symmetries for the low-temperature phases of (1) and (2) at temperatures T < 348 ± 5 K and high crystallographic symmetry due to rotational disorder for the high-temperature phases at temperatures T > 348 ± 5 K.
(Z = 2) with a = 9.94457 (5), b = 14.52927 (8), c = 9.16021 (5) Å, α = 90.53390 (30), β = 111.73080 (30), γ = 90.0049 (4)°, and V = 1229.414 (12) Å3 for (1) and a = 9.92009 (7), b = 14.51029 (11), c = 9.13585 (7) Å, α = 90.4769 (4), β = 111.6724 (4), γ = 89.9877 (6)°, and V = 1222.037 (16) Å3 for (2). The molecules are found to be ordered as a result of steric interactions between neighboring molecules, as shown by analyzing the distances between the atoms. Upon heating, both compounds undergo a first-order phase transition at temperatures Tc = 348 ± 5 K, as characterized by a relative jump of the lattice parameter of ∼16%. At 353 K, both structures have the space group P (Z = 4), with a = 14.2037 (2) Å, and V = 2865.52 (7) Å3 for (1) and a = 14.1346 (2) Å, and V = 2823.90 (7) Å3 for (2). Rietveld refinements were performed for the low-temperature phases measured at T = 295 K [Rwp = 0.0844 for (1), Rwp = 0.0940 for (2)] and for the high-temperature phases measured at T = 353 K [Rwp = 0.0891 for (1), Rwp = 0.0542 for (2)]. The combination of high-resolution X-ray powder diffraction measurements and variable-temperature magic-angle-spinning 13C, 29Si and 119Sn NMR experiments demonstrates low crystallographic and molecular (C1) symmetries for the low-temperature phases of (1) and (2) at temperatures T < 348 ± 5 K and high crystallographic symmetry due to rotational disorder for the high-temperature phases at temperatures T > 348 ± 5 K.Keywords: High-resolution X-ray powder diffraction; MAS NMR; symmetry; simulated annealing; tetrakis(trimethylstannyl)germane; tetrakis(trimethylstannyl)silane.
Supporting information
 | Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768101016688/os0078sup1.cif |
 | Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768101016688/os0078sisnmesup2.rtv |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768101016688/os0078gesnmesup3.rtv |
CCDC references: 1211608; 1211609
Computing details top
For both compounds, cell refinement: GSAS; program(s) used to solve structure: DASH; program(s) used to refine structure: GSAS.
(sisnme) top
Crystal data top
| SiSn4C12H36 | γ = 89.9877 (6)° |
| Mr = 683.3 | V = 1222.04 (2) Å3 |
| Triclinic, P1 | Z = 2 |
| a = 9.92009 (7) Å | Synchrotron radiation, λ = 0.491213(2) Å |
| b = 14.5103 (1) Å | µ = 8.09 mm−1 |
| c = 9.13585 (7) Å | T = 295 K |
| α = 90.4769 (4)° | white |
| β = 111.6724 (4)° | cylinder, 0.7 × 0.7 mm |
Data collection top
| ESRF BBM16 diffractometer | Data collection mode: transmission |
| Radiation source: synchrotron, bending magnet | Scan method: continuous |
| Si(111) double monochromator | 2θmin = 1.003°, 2θmax = 31.981°, 2θstep = 0.003° |
| Specimen mounting: lithiumborate glass capillary 0.7 mm diameter |
Refinement top
| Refinement on Inet | 46 restraints |
| Rp = 0.065 | 0 constraints |
| Rwp = 0.094 | H-atom parameters not defined |
| R(F2) = 0.1618 | (Δ/σ)max = 0.04 |
| Profile function: pseudo-Voigt | Background function: manual |
| 55 parameters |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
| x | y | z | Uiso*/Ueq | ||
| Si1 | 0.7645 (5) | 0.2509 (4) | 0.2435 (6) | 0.004 (4) | |
| Sn2 | 1.0211 (2) | 0.2495 (2) | 0.2364 (3) | 0.0601 (4) | |
| Sn3 | 0.7004 (3) | 0.0925 (2) | 0.3256 (3) | 0.0601 (4) | |
| Sn4 | 0.7435 (3) | 0.3693 (2) | 0.4387 (4) | 0.0601 (4) | |
| Sn5 | 0.5807 (3) | 0.2896 (2) | −0.0300 (3) | 0.0601 (4) | |
| C6 | 0.789 (2) | 0.5060 (7) | 0.370 (2) | 0.132 (3) | |
| C7 | 0.900 (1) | 0.3400 (9) | 0.671 (1) | 0.132 (3) | |
| C8 | 0.518 (1) | 0.366 (1) | 0.439 (2) | 0.132 (3) | |
| C9 | 0.850 (1) | 0.0617 (8) | 0.563 (1) | 0.132 (3) | |
| C10 | 0.474 (1) | 0.0970 (8) | 0.321 (2) | 0.132 (3) | |
| C11 | 0.720 (2) | −0.0128 (8) | 0.164 (2) | 0.132 (3) | |
| C12 | 0.589 (2) | 0.1849 (9) | −0.200 (1) | 0.132 (3) | |
| C13 | 0.360 (1) | 0.294 (1) | −0.022 (2) | 0.132 (3) | |
| C14 | 0.635 (2) | 0.4221 (8) | −0.103 (1) | 0.132 (3) | |
| C15 | 1.181 (1) | 0.225 (1) | 0.460 (1) | 0.132 (3) | |
| C16 | 1.036 (1) | 0.1456 (9) | 0.079 (2) | 0.132 (3) | |
| C17 | 1.066 (1) | 0.3783 (8) | 0.153 (2) | 0.132 (3) |
Geometric parameters (Å, º) top
| Si1—Sn2 | 2.570 (5) | Sn3—C10 | 2.24 (1) |
| Si1—Sn3 | 2.575 (5) | Sn3—C11 | 2.18 (1) |
| Si1—Sn4 | 2.529 (5) | Sn4—C6 | 2.18 (1) |
| Si1—Sn5 | 2.557 (5) | Sn4—C7 | 2.16 (1) |
| Sn2—C15 | 2.11 (1) | Sn4—C8 | 2.24 (1) |
| Sn2—C16 | 2.12 (1) | Sn5—C12 | 2.18 (1) |
| Sn2—C17 | 2.13 (1) | Sn5—C13 | 2.22 (1) |
| Sn3—C9 | 2.18 (1) | Sn5—C14 | 2.17 (1) |
| Sn2—Si1—Sn3 | 110.7 (2) | C9—Sn3—C10 | 109.5 (3) |
| Sn2—Si1—Sn4 | 111.3 (2) | C9—Sn3—C11 | 109.2 (3) |
| Sn2—Si1—Sn5 | 109.4 (2) | C10—Sn3—C11 | 110.4 (7) |
| Sn3—Si1—Sn4 | 107.7 (2) | Si1—Sn4—C6 | 109.3 (3) |
| Sn3—Si1—Sn5 | 108.9 (2) | Si1—Sn4—C7 | 109.7 (3) |
| Sn4—Si1—Sn5 | 108.7 (2) | Si1—Sn4—C8 | 109.1 (3) |
| Si1—Sn2—C15 | 112.0 (3) | C6—Sn4—C7 | 108.5 (3) |
| Si1—Sn2—C16 | 109.9 (3) | C6—Sn4—C8 | 109.4 (7) |
| Si1—Sn2—C17 | 109.9 (3) | C7—Sn4—C8 | 110.7 (3) |
| C15—Sn2—C16 | 108.7 (3) | Si1—Sn5—C12 | 109.7 (3) |
| C15—Sn2—C17 | 108.6 (3) | Si1—Sn5—C13 | 109.3 (3) |
| C16—Sn2—C17 | 107.6 (3) | Si1—Sn5—C14 | 109.4 (3) |
| Si1—Sn3—C9 | 109.3 (3) | C12—Sn5—C13 | 109.8 (7) |
| Si1—Sn3—C10 | 108.9 (3) | C12—Sn5—C14 | 108.5 (3) |
| Si1—Sn3—C11 | 109.3 (3) | C13—Sn5—C14 | 110.3 (3) |
(gesnme) top
Crystal data top
| GeSn4C12H36 | V = 1229.41 (1) Å3 |
| Mr = 727.9 | Z = 2 |
| Triclinic, P1 | Synchrotron radiation, λ = 0.491213(2) Å |
| a = 9.94457 (5) Å | µ = 10.5 mm−1 |
| b = 14.52927 (8) Å | T = 295 K |
| c = 9.16021 (5) Å | white |
| α = 90.5339 (3)° | cylinder, 0.7 × 0.7 mm |
| β = 111.7308 (3)° | Specimen preparation: Prepared at 248 K |
| γ = 90.0049 (4)° |
Data collection top
| ESRF BBM16 diffractometer | Data collection mode: transmission |
| Radiation source: synchrotron, bending magnet | Scan method: continuous |
| Si(111) double monochromator | 2θmin = 1.003°, 2θmax = 29.995°, 2θstep = 0.003° |
| Specimen mounting: lithiumborate glass capillary 0.7 mm diameter |
Refinement top
| Refinement on Inet | 46 restraints |
| Rp = 0.067 | 0 constraints |
| Rwp = 0.084 | H-atom parameters not defined |
| R(F2) = 0.1378 | (Δ/σ)max = 0.03 |
| Profile function: pseudo-Voigt | Background function: manual |
| 55 parameters |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
| x | y | z | Uiso*/Ueq | ||
| Ge1 | 0.7615 (3) | 0.2490 (2) | 0.2412 (3) | 0.016 (1) | |
| Sn2 | 1.0232 (2) | 0.2487 (2) | 0.2356 (3) | 0.0641 (5) | |
| Sn3 | 0.7019 (3) | 0.0891 (2) | 0.3246 (3) | 0.0641 (5) | |
| Sn4 | 0.7440 (3) | 0.3700 (2) | 0.4415 (3) | 0.0641 (5) | |
| Sn5 | 0.5792 (2) | 0.2897 (2) | −0.0346 (3) | 0.0641 (5) | |
| C6 | 0.798 (1) | 0.5050 (4) | 0.379 (1) | 0.136 (3) | |
| C7 | 0.893 (1) | 0.3349 (7) | 0.6751 (8) | 0.136 (3) | |
| C8 | 0.5239 (9) | 0.3709 (7) | 0.438 (2) | 0.136 (3) | |
| C9 | 0.849 (1) | 0.0601 (6) | 0.5614 (9) | 0.136 (3) | |
| C10 | 0.4815 (9) | 0.0890 (5) | 0.317 (2) | 0.136 (3) | |
| C11 | 0.724 (1) | −0.0152 (5) | 0.165 (1) | 0.136 (3) | |
| C12 | 0.588 (2) | 0.1867 (6) | −0.2035 (7) | 0.136 (3) | |
| C13 | 0.3621 (8) | 0.294 (1) | −0.032 (1) | 0.136 (3) | |
| C14 | 0.634 (1) | 0.4236 (6) | −0.1001 (9) | 0.136 (3) | |
| C15 | 1.1783 (6) | 0.2159 (9) | 0.4661 (9) | 0.136 (3) | |
| C16 | 1.0353 (7) | 0.1470 (8) | 0.067 (1) | 0.136 (3) | |
| C17 | 1.0715 (7) | 0.3837 (6) | 0.168 (2) | 0.136 (3) |
Geometric parameters (Å, º) top
| Ge1—Sn2 | 2.622 (3) | Sn3—C10 | 2.169 (6) |
| Ge1—Sn3 | 2.588 (3) | Sn3—C11 | 2.163 (6) |
| Ge1—Sn4 | 2.582 (3) | Sn4—C6 | 2.170 (6) |
| Ge1—Sn5 | 2.580 (3) | Sn4—C7 | 2.170 (6) |
| Sn2—C15 | 2.161 (6) | Sn4—C8 | 2.176 (6) |
| Sn2—C16 | 2.161 (6) | Sn5—C12 | 2.168 (6) |
| Sn2—C17 | 2.170 (6) | Sn5—C13 | 2.170 (6) |
| Sn3—C9 | 2.166 (6) | Sn5—C14 | 2.170 (6) |
| Sn2—Ge1—Sn3 | 110.0 (1) | C9—Sn3—C10 | 109.4 (5) |
| Sn2—Ge1—Sn4 | 110.1 (1) | C9—Sn3—C11 | 109.6 (2) |
| Sn2—Ge1—Sn5 | 108.9 (1) | C10—Sn3—C11 | 109.4 (2) |
| Sn3—Ge1—Sn4 | 108.3 (1) | Ge1—Sn4—C6 | 109.6 (2) |
| Sn3—Ge1—Sn5 | 110.4 (1) | Ge1—Sn4—C7 | 109.5 (2) |
| Sn4—Ge1—Sn5 | 109.09 (9) | Ge1—Sn4—C8 | 108.9 (2) |
| Ge1—Sn2—C15 | 109.6 (2) | C6—Sn4—C7 | 109.6 (2) |
| Ge1—Sn2—C16 | 109.4 (2) | C6—Sn4—C8 | 109.5 (2) |
| Ge1—Sn2—C17 | 109.4 (2) | C7—Sn4—C8 | 109.4 (5) |
| C15—Sn2—C16 | 109.4 (2) | Ge1—Sn5—C12 | 109.6 (2) |
| C15—Sn2—C17 | 109.5 (5) | Ge1—Sn5—C13 | 109.6 (2) |
| C16—Sn2—C17 | 109.5 (5) | Ge1—Sn5—C14 | 109.1 (2) |
| Ge1—Sn3—C9 | 109.6 (2) | C12—Sn5—C13 | 109.3 (6) |
| Ge1—Sn3—C10 | 109.4 (2) | C12—Sn5—C14 | 109.7 (2) |
| Ge1—Sn3—C11 | 109.5 (2) | C13—Sn5—C14 | 109.3 (5) |
