Hao Xia, Luo Min, Lin Chensheng, Peng Guang, Yan Tao, Lin Donghong, Cao LiLing, Long Xifa, Yang Guangsai, Ye Ning
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China.
Inorg Chem. 2020 Jul 20;59(14):10361-10367. doi: 10.1021/acs.inorgchem.0c01502. Epub 2020 Jun 28.
The first alkali-metal nitrate isocyanurates, A(HCNO)(NO) (A = K, Rb), were synthesized by the tactic of introducing (NO) into isocyanurate with a mild hydrothermal technique. They crystallized into the same monoclinic centrosymmetric (CS) space group 2/, which featured a 2D [(HCNO)(NO)] layered structure separated by K and Rb cations, respectively. Both compounds exhibited short ultraviolet cutoff edges (λ = 228 and 229 nm) and large birefringences (Δ = 0.253 and 0.224 at 546.1 nm). More importantly, in comparison with most of the isocyanurates and nitrates, they have better thermal stability with decomposition temperatures up to 319.8 and 324.4 °C. In addition, our theoretical calculations reveal that the π-conjugated groups play significant roles in improving the optical anisotropy. Remarkably, introducing a π-conjugated inorganic acid radical (NO) into isocyanurate is an extremely meaningful strategy to explore new UV birefringent crystals.
通过温和水热技术将(NO)引入异氰尿酸酯的策略合成了首例碱金属硝酸异氰尿酸酯A(HCNO)(NO)（A = K、Rb）。它们结晶为相同的单斜中心对称（CS）空间群2/，其特征是分别由K和Rb阳离子分隔的二维[(HCNO)(NO)]层状结构。两种化合物均表现出短的紫外截止边（λ = 228和229 nm）以及大的双折射（在546.1 nm处Δ = 0.253和0.224）。更重要的是，与大多数异氰尿酸酯和硝酸盐相比，它们具有更好的热稳定性，分解温度高达319.8和324.4 °C。此外，我们的理论计算表明，π共轭基团在改善光学各向异性方面起重要作用。值得注意的是，将π共轭无机酸根(NO)引入异氰尿酸酯是探索新型紫外双折射晶体的极具意义的策略。
