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 Feb 19;70(Pt 3):i14. doi: 10.1107/S1600536814003043. eCollection 2014 Mar 1.
Single crystals of Rb2Lu[Si4O10]F (dirubidium lutetium tetra-silicate fluoride) were obtained in flux-synthesis experiments in the system SiO2-Lu2O3-RbF. The compound belongs to the group of tubular chain silicates, i.e. it is based on multiple chains of condensed [SiO4] tetra-hedra forming closed columns. The periodicity of the unbranched multiple chains is four and corresponds to the length of the b axis. Adjacent columns are connected by Lu(3+) cations, which are coordinated by four oxide and two fluoride anions in the form of slightly distorted octa-hedra. By sharing common fluoride corners, the single octa-hedra are linked into chains running parallel to the silicate tubes. Electroneutrality is achieved by the incorporation of additional Rb(+) cations. All four symmetrically independent rubidium ions, four out of twelve oxide as well as the two fluoride anions are located on mirror planes. The remaining atoms reside on general positions.
在SiO₂-Lu₂O₃-RbF体系的助熔剂合成实验中获得了Rb₂Lu[Si₄O₁₀]F（二铷镥四硅酸盐氟化物）的单晶。该化合物属于管状链硅酸盐类，即它基于多个缩合的[SiO₄]四面体链形成封闭柱体。无分支的多链的周期性为4，与b轴长度相对应。相邻柱体由Lu(3+)阳离子连接，这些阳离子以轻微扭曲的八面体形式由四个氧化物和两个氟阴离子配位。通过共享共同的氟角，单个八面体连接成平行于硅酸盐管的链。通过引入额外的Rb(+)阳离子实现电中性。所有四个对称独立的铷离子、十二个氧化物中的四个以及两个氟阴离子位于镜面平面上。其余原子位于一般位置。
