Synthese und Kristallstrukturen von Bromid—Thiosilicaten Ln3Br[SiS4]2 der Lanthanide (Ln = La,Ce, Pr,Nd, Sm,Gd)

Synthesis and Crystal Structures of Lanthanide Bromide Thiosilicates Ln₃BrSiS₄]₂ (Ln = La, Ce, Pr, Nd, Sm, Gd) Single crystals of the bromide—thiosilicates Ln₃BrSiS₄]₂ were prepared by reaction of lanthanide metal (Ln = La, Ce, Pr, Nd, Sm, Gd), sulfur, silicon and bromine in quartz glass tubes. The thiosilicates crystallize in the monoclinic spacegroup C2/c (Z = 4) isotypically to the iodide analogues Ln₃I(SiS₄)₂ and the A—type chloride—oxosilicates Ln₃ClSiO₄]₂ with the following lattice constants: La₃BrSiS₄]₂: a = 1583.3(4) pm, b = 783.0(1) pm, c = 1098.2(3) pm, β = 97.33(3)° Ce₃BrSiS₄]₂: a = 1570.4(3) pm, b = 776.5(2) pm, c = 1092.2(2) pm, β = 97.28(2)° Pr₃BrSiS₄]₂: a = 1562.6(3) pm, b = 770.1(2) pm, c = 1088.9(2) pm, β = 97.50(2)° Nd₃BrSiS₄]₂: a = 1561.4(4) pm, b = 766.0(1) pm, c = 1085.3(2) pm, β = 97.66(3)° Sm₃BrSiS₄]₂: a = 1555.4(3) pm, b = 758.5(2) pm, c = 1079.9(2) pm, β = 98.28(2)° Gd₃BrSiS₄]₂: a = 1556.5(3) pm, b = 750.8(1) pm, c = 1074.5(2) pm, β = 99.26(2)° In the crystal structures the bromide ions form chains along 001] with trigonal planar coordination by lanthanide cations, while the SiS₄]^4‐—building units display isolated distorted tetrahedra.