Die Kristallstruktur des dimeren Dimethylantimontrichlorids und des Tetramethylantimon-hexachloroantimonats [(CH3)2SbCl3]2 und [(CH3)4Sb] + [SbCl6]- / Crystal Structure of the Dimeric Dimethylantimony Trichloride and Tetramethylantimony Hexachloroantimonate [(CH3)2SbCl3]2 and [(CH3)4Sb]+[SbCl6]-

Abstract

Dimethylstibonium trichloride (CH3)2SbCl3 exists in two isomeric forms. In the dimeric "covalent" one, [(CH3)2SbCl3]2, two formula units are bridged by chlorine, building a fourmembered ring. It crystallizes in the orthorhombic space group Pnma with lattice constants a = 1212.9, b = 1910 and c = 610.2 pm. The mean value of bond length from antimony to the terminal chlorine atoms is 235.5 pm, to the bridging chlorine atoms 280.0 pm and the averaged Sb-C distance is 213.3 pm. The second form [(CH3)4Sb]+[SbCl6]- is an ionic one and crystallizes in the triclinic space group P1̅ with lattice constants a = 715.6, b = 744.2, c = 1415.2 pm, a = 90.01, β = 93.39 and γ = 106.4°. The mean values of bond lengths are Sb-C 211.5 pm and Sb-Cl 238.2 pm. The tetrahedrical as well as the octahedrical coordination polyhedra are only slightly distorted.