Kahlenberg Volker, Manninger Tanja
University of Innsbruck, Institute of Mineralogy & Petrography, Innrain 52, A-6020 Innsbruck, Austria.
Acta Crystallogr Sect E Struct Rep Online. 2014 Jan 25;70(Pt 2):i11. doi: 10.1107/S1600536814001470. eCollection 2014 Feb 1.
Single-crystals of the title compound, nona-potassium triyttrium dodeca-silicate difluoride, were obtained from flux synthesis experiments in the system SiO2-Y2O3-KF. The crystal structure belongs to the group of single-layer silicates and is based on silicate sheets parallel to (110). A single layer contains secondary (Q (2)) and tertiary (Q (3)) silicate tetra-hedra in the ratio 1:2 and is build up from six-, eight- and twelve-membered rings. The linkage between neighboring layers is achieved by two crystallographically independent Y(3+) cations, which are coordinated by six oxygen ligands in form of distorted octa-hedra. Charge compensation is accomplished by incorporation of additional F(-) anions and K(+) cations in the structural channels, forming anion-centred [F2K7] groups. Apart from one K(+) and one Y(3+) cation (each with site symmetry -1), the 30 crystallographically independent atoms reside on general positions.
通过在SiO₂-Y₂O₃-KF体系中的助熔剂合成实验，获得了标题化合物九钾二氟十二钇硅酸盐的单晶。其晶体结构属于单层硅酸盐类，基于平行于(110)的硅酸盐片层。单层中二级(Q(2))和三级(Q(3))硅酸盐四面体的比例为1:2，由六元环、八元环和十二元环构成。相邻层之间的连接是通过两个晶体学独立的Y(3+)阳离子实现的，它们以扭曲八面体的形式由六个氧配体配位。电荷补偿通过在结构通道中引入额外的F(-)阴离子和K(+)阳离子来完成，形成以阴离子为中心的[F₂K₇]基团。除了一个K(+)和一个Y(3+)阳离子（每个具有对称位点-1）外，30个晶体学独立原子位于一般位置。
