Mixed‐Valence Thallium(I,III) Bromides. The Crystal Structure of α‐Tl₂Br₃.

Abstract

Structure Structure D 2000Mixed-Valence Thallium(I,III) Bromides. The Crystal Structure of α-Tl 2 Br 3 . -Single crystals of α-Tl 2 Br 3 are prepared by reaction of aq. solutions of TlBr 3 and Tl 2 SO 4 in agarose gel. β-Tl 2 Br 3 is obtained by rapid crystallization of aq. TlBr 3 /TlBr solutions or from TlBr/TlBr 2 melts. The structures of both modifications are very similar and can be described as mixed-valent thallium(I) hexabromothallates(III), Tl 3 [TlBr 6 ]. The α-Tl 3 [TlBr 6 ] modification crystallizes in the monoclinic space group C2/c with Z = 32, while the β-modification shows almost hexagonal metric (space group P2 1 /m, Z = 12). Both structures are composed of Tl 2 [TlBr 6 ]and Tl 4 [TlBr 6 ] + multilayers alternating parallel (001). -(ACKERMANN, R.; HIRSCHLE, C.; ROTTER, H. W.; THIELE*, G.; Z.