ChemInform Abstract: Rb₂LnGaSi₄O₁₂ (Ln: Y, Eu, Gd, Tb): Luminescent Mixed‐Anion Double Layer Silicates Containing Chains of Edge‐Sharing LnO₇ Pentagonal Bipyramids.

Abstract

Lanthanoids I 2800 Rb2LnGaSi4O12 (Ln: Y, Eu, Gd, Tb): Luminescent Mixed-Anion Double Layer Silicates Containing Chains of Edge-Sharing LnO 7 Pentagonal Bipyramids. -The four new rare earth gallosilicates (V) and (VII) are isotypic and crystallize in the monoclinic space group I2/a with Z = 8 (single crystal XRD). They are the first examples of rare earth gallosilicates that contain individually occupied tetrahedral Ga 3+ and Si 4+ sites. Characteristic building units of the structure are unbranched achter single silicate chains, infinite chains of edge-sharing LnO 7 pentagonal bipyramids, and the unprecedented mixed-anion double layers of composition [GaSi4O12]. The photoluminescence properties of (Vb) and (VII) are studied. The Y 3+ ion in (Va) can be partially replaced by Eu 3+ and Tb 3+ to produce luminescent materials.