Two New Crystals in LimCsnBm+nO2(m+n) (m + n = 5, 7; m > n) Series: Noncentrosymmet

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• 作者：Lin Li ; Shujuan Han ; Binghua Lei ; Xiaoyu Dong ; Hongping Wu ; Zhongxiang Zhou ; Zhihua Yang ; Shilie Pan
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：August 3, 2015
• 年：2015
• 卷：54
• 期：15
• 页码：7381-7387
• 全文大小：495K
• ISSN：1520-510X

文摘

With the introduction of an alkali metal into the B鈥揙 framework, two new alkali metal borate crystals, Li₅Cs₂B₇O₁₄ and Li₄CsB₅O₁₀, have been obtained for the first time. Both compounds obey a general formula of Li_mCs_nB_m+nO_2(m+n) (m + n = 5, 7; m > n). The two crystals have different three-dimensional (3D) framework structures composed by LiO_n (n = 4, 5), CsO₁₀, BO₃, and BO₄ units. Li₅Cs₂B₇O₁₄ crystallizes into the polar and noncentrosymmetric space group Ama2, while Li₄CsB₅O₁₀ belongs to the nonpolar and centrosymmetric space group P2₁/c. Detailed structure comparison analysis indicates that the different arrangements of the anionic groups in Li_mCs_7鈥?i>mB₇O₁₄ (m = 4, 5) and Li_mCs_5鈥?i>mB₅O₁₀ (m = 3, 4) may arise from the cation size effects, bond-valence requirements, and differences of coordination environment. In addition, in order to get better understandings of electronic structures and linear optical properties, we also carried out first-principle theoretical studies.