Preparation and structures of two anionic antimony(III) mixed halides, Hpy[SbBr2Cl2] and [HPY](8)[Sb4Br12Cl8]

Structures are reported for two anionic antimony(III) bromide chlorides, Hp y[SbBr2Cl2] and [Hpy(4)][Sb4Br12Cl8] both of which are subject to halogen d isorder. The first compound has an infinite chain structure in which antimo ny coordination is raised to six by the formation of double halogen bridges by atoms with high bromine content. The structure of the second compound i s based on a distorted square of antimony atoms, again in distorted octahed ral coordination. The antimony atoms are linked together by single bromine bridges and chlorine atoms or atoms with high chlorine content occupy the t rans positions. The pattern of Sb Br bridging distances suggests that the s tructure is derived by interconnection of two singly bridged [Sb2Br5Cl4](3- ) units by two bridging B-r- ions. (C) 1998 Elsevier Science Ltd. All right s reserved.