N. V. Alekseev

Electron diffraction study of the molecular structure of trimethylcyclopentadienylsilane

Abstract The molecular structure of trimethylcyclopentadienylsilane, C 5 H 5 Si(CH 3 ) 3 , has been studied by electron diffraction in the vapour phase. The Si atom is found to be bonded by the localized σ-bond with one of the cyclopentadienyl carbon atoms. The SiC bond distances are 1.90±0.01 A. The cyclopentadienyl ring has an “envelope” conformation, the dihedral angle between planar four- and three-membered fragments of the ring being 22±4°. The SiC bond makes an angle of 56±4° with the plane of the bent-out “envelope flap”. Assuming the equality of all CH bond lengths and also of three CC bond lengths within the planar four-membered fragment of the cyclopentadienyl ring, the following values are obtained: r (C-H) = 1.11± 0.02, r (CC) = 1.53±0.03, r (CC) = 1.40±0.02 A

Molecular structure of dirhenium decacarbonyl

Abstract The molecular structure of Re 2 (CO) 10 has been determined by electron diffraction methods and the following bond lengths found: ReRe 3.04, ReC 2.01 and CO 1.16 A. Equatorial CO groups of neighbouring rhenium atoms are found to be in an eclipsed conformation.

Molecular structure of (tribromogermyl)manganese pentacarbonyl, Br3GeMn(CO)5

The Molecular Structure Of Br3gemn(co)5 Was Determined By Electron Diffraction and the following bond lengths were found: Mn–Ge 2.44, Ge–Br 2.31, Mn–C 1.84, C–O 1.16 A.

Electron diffraction study in the vapor phase of the molecular structure of dicyclopentadienylzirconium dichloride

Abstract The molecular structure of (C 5 H 5) ) 2 ZrCl 2 has been studied by electron diffraction in the vapor phase. The molecule is a wedge-like sandwich with the interring angle of 46° and bond distances of: ZrCl 2.309, ZrC 2.522, CC 1.42, CH 1.13 A

Electron diffraction study in the vapour phase of the molecular structure of dicyclopentadienylnickel

Abstract The molecular structure of nickelocene, (C 5 H 5 ) 2 Ni, has been studied by electron diffraction in the vapour phase. The molecule has eclipsed configuration with NiC 2.160, CC 1.41 and CH 1.10 ». CH bonds are bent out of the planes of the cyclopentadienyl rings towards the metal atom by 5°. This effect, which is general for dicyclopentadienyl sandwich compounds, is interpreted in terms of the new electron gas model as being a result of the repulsion between the electron clouds of the CH bonds and the π-electron density of the cyclopentadienyl ring.

Electron-diffraction study of the molecular structure of gem-difluorocyclopropyltrichlorosilane

The present paper describes a continuation of a cycle of studies of the structure of cyclopropyl derivatives of silicon [1-3], involving the study of the structure of the molecule of gem-difluorocyclopropyltrichlorosilane. The compound was synthesized by the published method [4] under the direction of Professor V. F. Mironov (to whom the authors express their thanks), and had the following characteristics: bp = 121-122 ~ n; ~ = 1.4185, d~ ~ = 1.4420. The electron diffraction patterns were obtained on a specialized electron diffraction apparatus for the study of the structure of molecules at room temperature, accelerating voltage 60 kV, volatilizer jet-photographic plate distance ~185 and ~392 mm, angle of opening of the blades of the sector assembly proportional to S 3. The method of measuring the accelerating voltage, the apparatus for the photometric measurements of the electron diffraction patterns of the molecules, and the procedure for processing the results of the photometeric measurements were described in [5-7]. The experimental curve for the molecular component of the intensity of scattering was separated by graphical construction of the background line. The SM(s)exp: curve was obtained in the range 2.3-32.0 ~-~ In the range 0-5 min, the experimental curve of the molecular component of the intensity was supplemented by the section of the theoretical curve for the most suitable model of the molecule. The SM(s)expt and f(r)exp t curves are given in Figs. 1 and 2 (in the calculation of the experimental radial distribution curve, the index of the exponent was taken as 0.002).