Improvements of and Insights into the Isolation of Bismuth Polycations from Benzene Solution – Single‐Crystal Structure Determinations of Bi 8 [GaCl 4 ] 2 and Bi 5 [GaCl 4 ] 3

The synthesis, crystal growth and structure are reported for the two salts Bi 5 [GaCl 4 ] 3 and Bi 8 [GaCl 4 ] 2 . The compounds are prepared from a solution of BiCl 3 and GaCl 3 in benzene, using gallium metal as reducing agent. Bi 8 [GaCl 4 ] 2 contains a Bi 8 2+ polycation that, essentially, adopts an ideal square antiprismatic geometry. The compound crystallizes in the P 6 3 space group; a = 17.760(2) Å and c = 12.979(3) Å. Bi 5 [GaCl 4 ] 3 crystallizes in the R 3 c space group, a = 11.814(2) Å, c = 29.974(3) Å, and contains a Bi 5 3+ cation adopting a trigonal‐bipyramidal geometry. The cation is slightly distorted from the ideal D 3 h symmetry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)