The Structures of M2X93−(M = Bi ; X = Cl, Br) Ions Determined by Rietveld Analysis of X-Ray Powder Diffraction Data

The results of the Rietveld analysis of X-ray powder diffraction data for title compounds show that the space group for (CH3NH3)3Bi2Cl9 is Pnma with Z = 4 and its lattice constants are a = 2040.6, b = 770.0, c = 1324.6 pm. It consists of one–dimensional double chains of Bi2Cl93− polyanions. The space group for [N(CH3)4]3Bi2X9 (X = Cl, Br) is P63/mmc with Z = 2 and its lattice constants are a = 926.2, c = 2192.2 pm for X = Cl and a = 951.8, c = 2245.9 pm for X = Br. It contains ioslated Bi2X93− anions with a triple bridged bioctahedral structure.