Zur Stereochemie des freien Elektronenpaares in Verbindungen des vierwertigen Tellurs: Verzerrtes TeCI62-Oktaeder in [H3N(CH2)3NH3TeCI6 regulär oktaedrisches Anion in H3N(CH2)3NH3SnCI6

Abstract

Using 293 K diffractometer intensity data, the structures of [H3N(CH2)3NH3]TeCl6 and [H3N(CH2)3NH3]SnCl6 have been determined by single crystal X-ray technique and refined to a final of 0.027 and 0,029, respectively. The yellow crystals of the tellurate are orthorhombic (space group Pnma) with a = 22.952(2), b = 7.5414(4), c - 7.801(1) Å and Z = 4. This structure contains distorted TeCl62- octahedra (distances Te - Cl min. 2.426(1), max. 2.672(1) Å ) with approximate 2mm point symmetry. In contrast, the SnCl62- ion in the second title com pound is octahedral with only small deviations from m 3m symmetry (distances Sn -Cl mean: 2.438(3) Ä ). The colourless crystals of this tin com pound are orthorhombic (space group Pnma) with a - 17.6082(9), b = 7.1809(3), c = 10.190(1) Å and Z = 4. Considering the TeX62- (X = Cl, Br, I) salts known to date, a distorted species is an exception, although a distortion is predicted by the VSEPR theory. The results agree with the rules for the appearance of a static stereochemical effect of the lone pair electrons in the TeX62- species.