Improvements of and insights into the isolation of bismuth polycations from benzene solution -: Single-crystal structure determinations of Bi8[GaCl4]2 and Bi5[GaCl4]3

The synthesis, crystal growth and structure are reported for the two salts Bi-5[GaCl4](3) and Bi-8[GaCl4](2). The compounds are prepared from a solution of BiCl3 and GaCl3 in benzene, using gallium metal as reducing agent. Bi-8[GaCl4](2) contains a Bi-8(2+) polycation that, essentially, adopts an ideal square antiprismatic geometry. The compound crystallizes in the P6(3) space group; a = 17.760(2) Angstrom and c = 12.979(3) Angstrom. Bi-5[GaCl4](3) crystallizes in the R3c space group, a = 11.814(2) Angstrom, c = 29.974(3) Angstrom, and contains a Bi-5(3+) cation adopting a trigonalbipyramidal geometry. The cation is slightly distorted from the ideal D-3h symmetry. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.