LEWIS-ACID-BASE-REACTIONS OF GOLD TRIHALI DES WITH BISMUTH TRIHALIDES- SYNTHESIS AND STRUCTURES OF AUBIX6 (X = CL, BR)

Gold trihalides AuX3 (X = Cl, Br) react with bismuth trihalides in sea led glass ampoules to the 1:1 adducts AuBiX6 (X=Cl, Br). AuBiCl6 is ob tained by a chemical transport reaction at 220 degrees C, whereas AuBi Br6 was synthesized by solvothermal reaction in SiBr4 at 150 degrees C . Both compounds crystallize triclinic, space group <P(1)over bar>, Z= 4. AuBiCl6: a=698.3(4) pm; b=1009.3(5) pm; c=1381(1) pm; alpha=104.98( 5)degrees; beta=94.73(5)degrees; gamma=110.06(3)degrees; V=867(1).10(6 ) pm(3) AuBiBr6: a=735.7(4) pm; b=1055.7(5) pm; c=1445(1) pm; alpha=10 4.88(5)degrees; beta=94.25(5)degrees; gamma=110.18(4)degrees; V=1001(1 ).10(6) pm(3). The structures are build formally of square-planar [AuX 4](-) and chains of edge-connected ([BiX4/2](+))(n) units. Since each Bi ion is surrounded by eight halogenide ions in a square-antiprismati c form, the structure can alternatively be described as consisting of chains of edge sharing ([BiX4X4/2-](3-))(n) antiprisms connected by Au 3+ ions.