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Updated: Oct 14, 2025
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
K3Na(TaF7)(SiF6): a mixed-anion pentanary fluoride with zero-dimensional anions exhibiting a large band gap
Ru-Ling Tang1, Xin Lian1, Wen-Dong Yao1
1School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, P. R. China. spguo@yzu.edu.cn.
Abstract:
Metal halides have potential applications in many optics-related fields, such as birefringence materials. Here, a pentanary fluoride K3Na(TaF7)(SiF6) has been obtained through a facile hydrothermal route. It crystallizes in the orthorhombic space group Immm, and its zero-dimensional framework features isolated SiF6 octahedra and TaF7 monocapped trigonal prisms, a new type of combination representing a new structure-type. It exhibits two wide optical band gaps of 4.46 eV and 5.67 eV which is consistent with DFT calculation. K3Na(TaF7)(SiF6) exhibits a larger birefringence (0.045 at 253.7 nm) compared with the commercial MgF2 crystal.
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