Accession Number:

AD0613486

Title:

THE CRYSTAL STRUCTURE OF ALPHA-DIMETHYLTELLURIUM DICHLORIDE,

Descriptive Note:

Corporate Author:

CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY

Report Date:

1958-03-25

Pagination or Media Count:

8.0

Abstract:

Alpha-dimethyltellurium dichloride crystallizes in the monoclinic system with the space-group symmetry P2 sub 1c. There are four molecules of CH32TeCl2 in the unit cell, the dimensions of which are a 9.552, b 6.180, c 11.314 A all 0.010 A, Beta 97.90.1 degrees. The trial structure was determined by use of Fourier syntheses on 010 and 001 based on Weissenberg photographs prepared with Cu K alpha radiation. The structure was refined by use of a three-dimensional Fourier synthesis and five three-dimensional leastsquares cycles based on Weissenberg photographs prepared with Mo K alpha radiation. The molecular symmetry approximates mm2 and may be described as a trigonalbipyramid with one equatorial position vacant. As in other molecules of the type R3SbX2, R2Se,TeX2, RICl2, ClF3, etc., the axial bonded distances to the halogen atoms are longer than the sums of the normal single covalent radii. An unusual feature of the dimethyltellurium dichloride structure is that the Cl-Te-Cl angle is bent toward the methyl groups. In the aromatic compounds such as diphenyltellurium dibromide the bending of these bonds is away from the organic groups. Fairly strong interaction between the tellurium atom of one molecule and one chlorine atom on each of two adjacent molecules is indicated. The positions of the additional chlorine atoms are approximately such as to complete the octahedron about the tellurium atom. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE