The Molecular Structure of Tetramethylgermane Determined by Gas Phase Electron Diffraction

1975 ◽  
Vol 53 (23) ◽  
pp. 3542-3544 ◽  
Author(s):  
J. Lawrence Hencher ◽  
Frank J. Mustoe
Keyword(s):  
Molecular Structure ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Interatomic Distance ◽  
Structural Parameters ◽  
Random Errors ◽  
Tetrahedral Symmetry ◽  
Interatomic Distances ◽  
Systematic And Random Errors ◽  
Gas Phase Electron Diffraction

The molecular structure of tetramethylgermane has been determined by vapor phase electron diffraction. The structural parameters, based on rg interatomic distances are r(GeC) = 1.945 ± 0.003 Å, r(CH) = 1.12 ± 0.02 Å, and [Formula: see text] Tetrahedral symmetry of the GeC4 skeleton was preserved in the analysis by including a shrinkage correction for the C … C interatomic distance. The quoted uncertainties were estimated to include both systematic and random errors.

An Electron-Diffraction Investigation of the Molecular Structure of Toluene

1977 ◽  
Vol 32 (9) ◽  
pp. 1063-1064 ◽  
Author(s):  
Takao Iijima
Keyword(s):  
Molecular Structure ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Structural Parameters ◽  
Electron Diffraction Investigation ◽  
Gas Phase Electron Diffraction

AbstractThe structural parameters of toluene have been deter­ mined by gas-phase electron diffraction. The bond distances in rg are as follows: C-C(ring) 1.399± 0.002 Å, C-C (me­thyl) 1.524± 0.007 Å, C -H(ring) 1.11 ± 0.01 Å. and C-H-(methyl) 1.10 ±0.02 Å.

scholarly journals MOLECULAR STRUCTURE OF TRYPTOPHAN: GAS PHASE ELECTRON DIFFRACTION AND QUANTUM-CHEMICAL STUDIES

2020 ◽  
Vol 63 (3) ◽  
pp. 37-45
Author(s):  
Valeriya V. Dunaeva ◽  
Georgiy V. Girichev ◽  
Nina I. Giricheva
Keyword(s):  
Molecular Structure ◽  
Amino Acids ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Structural Parameters ◽  
Electron Diffraction Data ◽  
Geometrical Parameters ◽  
Intramolecular Hydrogen ◽  
Gas Phase Electron Diffraction

The molecular structure and conformational properties of tryptophan have been investigated by gas-phase electron diffraction and theoretical methods. Quantum chemical calculations realized by program Gaussian 03 (B3LYP/cc-pVTZ) have been predicted the existence of six conformers at the temperature of experiment (T = 495 K). The ability of gas-phase electron diffraction method to distinguish the structure of conformers was estimated theoretically. Conformers have different orientations of carboxylic and amine group, backbone and indole fragment to each other. These conformers can be divided on two groups: distinguishable parameters (with different torsion angle C(OOH)-C(HNH2)-C(H2)-C(ind)) and weekly distinguishable ones (with different torsion angles H-N-C-C and H-O-C-C) by gas-phase electron diffraction. The molecular parameters of the conformers were determined. The conformers have intramolecular hydrogen bonding of the H2N···HO. The analysis of the gas-phase electron diffraction data have been carried out assuming the saturated vapor of tryptophan at T = 495 K consists of mixture at least of two conformers with lowest energy. It was shown that optimal ratio between conformers I : II was 50 : 50, respectively. The geometrical parameters of amino acids molecules (glycine, alanine, tryptophan) obtained by gas-phase electron diffraction were compared. The influence of the intramolecular hydrogen bond was established onto the structural parameters of the backbone of the above amino acids molecules.

The Molecular Structure of (Dichloromethyl)-trichlorosilane

1980 ◽  
Vol 35 (12) ◽  
pp. 1402-1407 ◽  
Author(s):  
V. Typke ◽  
M. Dakkouri ◽  
M. Schiele
Keyword(s):  
Molecular Structure ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Error Propagation ◽  
Structural Parameters ◽  
Structural Data ◽  
Systematic Errors ◽  
In Parenthesis ◽  
Gas Phase Electron Diffraction ◽  
Angle Of Rotation

Abstract The molecular structure of (dichloromethyl)-trichlorosilane has been determined by gas phase electron diffraction. It has been found that the effective structure of the molecule has C1-symmetry with an angle of rotation τ and a tilt angle ψ of the SiCl3-group. Several vibrational amplitudes were fixed at values calculated from transferred Urey-Bradly force constants.Systematic errors resulting from the uncertainties of the fixed parameters have been calculated applying the rules of error propagation. The most important structural parameters (rg in Å, angles in degrees) are: r(Si-C) = 1.905(10), r(Si-Cl) = 2.019(1), r(C-Cl) = 1.774(4), r(C-H) = 1.16(4), ∢ (C-Si-Cl) = 109.8(3), ∢(Si-C-Cl) = 111.4(8), ψ= 4.1(1.0), τ= 6.7(1.4) (the errors in parenthesis include the systematic contributions).Comparison is made with structural data of other representatives of the series CH3-mClmSiCl3 (m = 0, 1, 2, 3).

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