Über Tetrabromothallate MTlBr4 (M = K, Rb, Cs, NH4)

Die Tetrabromothallate MTlBr4 (M = K, Rb, Cs, NH4) sind durch Entwassern der entsprechenden Hydrate MTlBr4. nH2O oder durch Umsetzung von TlBr, MBr und Br2 bei 400°C in geschlossenen Glasampullen zu erhalten. KTlBr4 und NH4TlBr4 kristallisieren orthorhombisch im Ga[GaCl4]-Typ mit den Gitterkonstanten a = 795,2(3), b = 1036,0(4), c = 1042,1(5) pm, (KTlBr4) bzw. a = 812,6(3), b = 1070,1(13), c = 1110,6(10) pm (NH4TlBr4). On the Tetrabromothallates MTlBr4 (M = K, Rb, Cs, NH4) The tetrabromothallates MTlBr4 (M = K, Rb, Cs, NH4) were obtained by dehydratisation of the appropriate hydrates MTlBr4 · nH2O and by the reaction of TlBr, MBr, and Br2 in closed glass tubes at 400°C. KTlBr4 and NH4TlBr4 crystallize orthorhombic in the Ga[GaCl4]-type with the following lattice constants a = 795.2(3), b = 1036.0(4), c = 1042.1(5) pm (KTlBr4), and a = 812.6(3), b = 1070.1(13), c = 1110.6(10) pm (NH4TlBr4), respectively.