Crystal structure of dimethyl-bis(trimethylsilylethynyl) germanium

Ovchinnikov, Yu. É.; Struchkov, Yu. T.; Yarosh, O. G.; Воронков, М. Г.

doi:10.1007/bf02578296

Cited by 2 publications

(10 citation statements)

References 2 publications

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“…Atom C(42) is disordered between two opposite ªflapº positions with occupancy ratios of 0.70/0.30. The same type of disorder was found for 1-(2'-methoxyphenyl)-3,7,10-trimethylstannatrane [13]. Fortunately, the nonequivalent occupation of the positions C(42 A) and C(42 B) allows unambiguous assignment of the isomers, the major one having (S (at C22), R (at C32), S (at C42 A)) and the minor (S (at C22), R (at C32), R (at C42 B) configuration.…”

Section: Molecular Structure Ofsupporting

confidence: 68%

“…This pattern is a general feature of the ªatraneº framework for a variety of germatranes. The composition of mixtures can be examined by 13 C NMR spectroscopy as described earlier for other 1-substituted 3,7,10-trimethylgermatranes [3±6]. Chemical shifts of the protons and carbon atoms of the Me 3 M and fluorenyl groups are in the expected range.…”

Section: Methodsmentioning

confidence: 99%

“…NMR spectra were recorded at 25°C on Varian VXR-400 and Bruker AC 300 spectrometers, CDCl 3 was used as a solvent and for internal deuterium lock. The chemical shifts (d) of the 1 H and 13 C NMR resonances are given in ppm relative to internal TMS. Assignments of the 13 C NMR data were supported by APT experiments.…”

Section: Methodsmentioning

confidence: 99%

“…The coordination polyhedron at the germanium atom in 1 is typical for germatrane derivatives (all in b-position to the nitrogen atom) occupy ªflapº sites while C-α atoms sit on the base envelope planes; this seems to be a characteristic feature for all structures of 3,7,10-methylsubstituted atranes [7,8,13]. Atom C(42) is disordered between two opposite ªflapº positions with occupancy ratios of 0.70/0.30.…”

Section: Molecular Structure Ofmentioning

confidence: 99%

“…Before we started our work only a few 1-substituted 3,7,10-trimethylgermatranes had been reported [3±6]. Analysis of the available spectral data, preferably 1 H and 13 C NMR, clearly shows that mixtures of two diastereomers were obtained in any case. These isomers differ in the orientations of the methyl groups relative to the N → Ge bond axis and the asymmetric stereoisomer is always formed as the major product.…”

Section: Introductionmentioning

confidence: 96%

See 4 more Smart Citations

Synthesis and Characterisation of 1-[9-(H, Me3Si, Me3Ge, Me3Sn)9-Fluorenyl]-3,7,10-trimethylgermatranes. The Crystal Structure Analysis of 1-(9-Fluorenyl)-3,7,10-trimethylgermatrane

Зайцева

Karlov

Pen'kovoy

et al. 1999

Z. anorg. allg. Chem.

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Section: Molecular Structure Ofsupporting

confidence: 68%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Molecular Structure Ofmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 3 more Smart Citations

Synthesis and Characterisation of 1-[9-(H, Me3Si, Me3Ge, Me3Sn)9-Fluorenyl]-3,7,10-trimethylgermatranes. The Crystal Structure Analysis of 1-(9-Fluorenyl)-3,7,10-trimethylgermatrane

Зайцева

Karlov

Pen'kovoy

et al. 1999

Z. anorg. allg. Chem.

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An enormous vibrational motion: the gas-phase structure of dimethyl-bis(methoxyethynyl) germanium

et al. 2004

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The structure of dimethyl-bis(methoxyethynyl) germanium has been determined in the gas phase by electron diffraction utilising flexible restraints from quantum chemical calculations. Theoretical methods (B3LYP/6-311+G* and MP2/6-311+G*) predict a low barrier to rotation of the methoxy groups in the molecule in addition to low-frequency vibrations of the long ethynyl chains. In the equilibrium structure the Ge-C[triple bond]C angles of the two methoxyethynyl fragments in the molecule are computed to deviate by up to 4 degrees from the linear arrangement. As a consequence of low-frequency large-amplitude vibrational motion the experimental structure of these fragments without applying vibrational corrections deviates considerably from linearity, while the structure corrected for vibrational effects using the harmonic approximation and taking into account a non-linear transformation between internal and Cartesian coordinates (r(h1)) shows closer agreement with theory. The main experimental structural parameters of dimethyl-bis(methoxyethynyl) germanium (r(h1)) are: r(Ge-C)(mean), 192.5(1) pm; DeltaGeC =r(Ge-C(methyl))-r(Ge-C(ethynyl)), 4.5(5) pm, r(C[triple bond]C)(mean), 122.8(2) pm; r(C-O)(mean), 138.9(3) pm; DeltaCO =r(C(methyl)-O)-r(C(ethynyl)-O), 14.5(2) pm, r(C-H)(mean), 109.1(4) pm; [angle](X-C-H)(mean)(X = Ge,O), 109(1) degree; [angle]C(ethynyl)-Ge-C(ethynyl), 108.1(4) degree; [angle]C(methyl)-Ge-C(methyl), 113.4(5) degree; [angle]Ge-C[triple bond]C, 163(1) degree; [angle]C[triple bond]C-O, 176(2) degree; [angle]C-O-C, 115.2(6) degree; methoxy group torsion, tau, 36(9) degree from the position in which the C-O bond eclipses the further Ge-C(ethynyl) bond.

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Crystal structure of dimethyl-bis(trimethylsilylethynyl) germanium

Cited by 2 publications

References 2 publications

Synthesis and Characterisation of 1-[9-(H, Me3Si, Me3Ge, Me3Sn)9-Fluorenyl]-3,7,10-trimethylgermatranes. The Crystal Structure Analysis of 1-(9-Fluorenyl)-3,7,10-trimethylgermatrane

Synthesis and Characterisation of 1-[9-(H, Me3Si, Me3Ge, Me3Sn)9-Fluorenyl]-3,7,10-trimethylgermatranes. The Crystal Structure Analysis of 1-(9-Fluorenyl)-3,7,10-trimethylgermatrane

An enormous vibrational motion: the gas-phase structure of dimethyl-bis(methoxyethynyl) germanium

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