Einkristalle von Y3F[Si3O10] im Thalenit-Typ

Single Crystals of Y₃FSi₃O₁₀] with Thalenite-Type Structure Colourless, diamond-shaped single crystals of Y₃FSi₃O₁₀] (monoclinic, P2₁/n; a = 730.38(5), b = 1112.47(8), c = 1037.14(7) pm, β = 97.235(6)°, Z = 4) with thalenite-type structure are obtained upon the reaction of YF₃ with Y₂O₃ and SiO₂ (1 : 4 : 9 molar ratio) in evacuated silica tubes at 700 °C in the presence of CsCl as flux within seven days. The crystal structure consists of triangular FY₃]⁸⁺ cations and catena-trisilicate anions Si₃O₁₀]^8–, which exhibit a horseshoe-shape resulting from two vertex-shared terminal SiO₄] tetrahedra with both staggered and eclipsed conformation relative to the central one. The Y³⁺ cations have coordination numbers of seven plus one (Y1) or seven (Y2 and Y3), but only one F^– anion belongs to each and vice versa, the remainder ligands being oxygen members of Si₃O₁₀]^8– anions.