The first alkali metal and magnesium mixed borate fluoride, Li 0.8Mg2.1B2O5F, was prepared by the high-temperature solution method. It crystallizes in the monoclinic space group P21/n (no. 14) with lattice constants a = 3.0881(4) A˚, b = 13.6020(2) A˚, c = 9.6563(1) A˚, β = 91.744(9)°, Z = 4. In the structure, a special magnesium-oxygen-fluorine octahedral chain is found in borates for the first time. The octahedral chains are linked into a three-dimensional framework containing tunnels with 1 ∞[LiO4]7- chains and isolated B 2O5 groups filling in. The differences of octahedral chains in Li0.8Mg2.1B2O5F and magnesium inosilicate minerals are discussed. The TG-DSC curves, IR spectrum and UV-Vis-NIR diffuse reflectance spectrum were measured.
Chinese Acad Sci, Xinjiang Tech Inst Phys & Chem, Key Lab Funct Mat, Key Lab Funct Mat & Devices Special Environm CAS, Urumqi 830011, Peoples R China;Univ Chinese Acad Sci, Beijing 100049, Peoples R China
Wang, Zheng,Zhang, Min,Pan, Shilie,et al. Li0.8Mg2.1B2O5F: the first borate fluoride with magnesium-oxygen-fluorine octahedral chains[J]. Dalton Transactions,2014,43(7):2828-2834.