Die kristallstrukturen von tetramethylarsonium-dichlorodimethylgallat [(CH 3) 4As] + [(CH 3) 2GaCl 2] − und tetramethylarsonium-trichloromonomethylgallat [(CH 3) 4As] + [CH 3GaCl 3] −

Abstract

Tetramethylarsonium dichlorodimethylgallate [(CH 3) 4As] + [(CH 3) 2GaCl 2] − crystallizes in the monoclinic space group P2 1/ c. The unit cell with lattice constants a  7.511, b  11.734, c  14.908 Å and β  99.75° includes four formula units. The mean values of the bond lengths are: AsC 1.923, GaCl 2.277 and GaC 1.980 Å. Tetramethylarsonium trichloromonomethylgallate [(CH 3) 4As] + [CH 3GaCl 3] − also crystallizes in the monoclinic space group Pc with two formula units in the cell. The lattice constants are a  7.104, b  6.640, c  13.385 Å and β  93.82°. Mean bond lengths: AsC 1.941, GaCl 2.223 and GaC 1.934 Å. In both compounds both As and Ga are tetrahedrally surrounded; the anionic tetrahedra are markedly distorted.