基于分子工程的方法设计首例具有Sr_(2)Be_(2)B_(2)O_(7)(SBBO)结构的深紫外氟碳酸盐双折射晶体AMgLi_(2)(CO_(3))_(2)F(A=K,Rb)  

Molecular Engineering Design of the First Sr_(2)Be_(2)B_(2)O_(7)-type Fluoride Carbonates AMgLi_(2)(CO_(3))_(2)F(A=K,Rb)as Deep-Ultraviolet Birefringent Crystal

作　　者：宋云霞 梁飞[3] 田皓天 吴燕 罗敏[2] Song Yunxia;Liang Fei;Tian Haotian;Wu Yan;Luo Min(School of Electronic,Electrical Engineering and Physics,Fujian University of Technology,Fuzhou 350108,China;Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China;Institute of Crystal Materials,Shandong University,Jinan 250100,China)

机构地区：[1]福建工程学院电子电气与物理学院,福州350108 [2]中国科学院福建物质结构研究所中国科学院光电材料化学与物理重点实验室,福州350002 [3]山东大学晶体材料研究院,济南250100

出　　处：《化学学报》2022年第2期105-109,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.21975255);福建省自然科学基金(Nos.2019J01020758,2021J011080);福建省教育厅项目(No.JT180331);福建工程学院科研启动基金(No.GY-Z20042);中国科学院青年创新促进会(No.2019303)资助.

摘　　要：分子结构设计是开发新化合物和通过原子尺度操纵优化晶体结构的一种引人注目的策略.在这个工作中,利用分子工程的思想,基于SBBO结构,成功设计并合成两个新型氟碳酸盐KMgLi_(2)(CO_(3))2F和RbMgLi_(2)(CO_(3))_(2)F.在两个结构中,a−b平面是由CO_(3)和LiO_(3)F阴离子基团组成的无限[Li_(3)C_(3)O_(6)F_(3)]_(∞)层,进一步相邻的层通过F原子连接形成一个独特的[Li_(6)C_(6)O_(12)F_(3)]_(∞)双层.这种结构特征对改善晶体的层状生长习性和消除晶体的多晶性有很大的帮助.光学测试表明,该系列晶体具有大的双折射和短的紫外截止边,是深紫外双折射晶体良好的候选材料.Molecular engineering design is an effective strategy to develop new compounds and optimize the crystal structure by atomic-scale manipulation.In this work,a novel series of fluoride carbonates AMgLi_(2)(CO_(3))_(2)F(A=K,Rb)are rationally developed by taking Sr_(2)Be_(2)B_(2)O_(7)(SBBO)as the parent compound.Their crystal structures are established by single crystal X-ray diffraction.KMgLi_(2)(CO_(3))_(2)F belongs to centrosymmetric hexagonal system and crystallizes in P63/m with a=b=0.4775 nm,c=1.4782 nm.RbMgLi_(2)(CO_(3))_(2)F crystallizes in the centrosymmetric trigonal space group P3̅1c with a=b=0.4787 nm,c=1.4966 nm.In all of their structures,the a−b plane is the infinite lattice layer[Li_(3)C_(3)O_(6)F_(3)]_(∞) made up of[CO_(3)]and[LiO_(3)F]anionic groups.The adjacent layers are further connected with fluorine bridge atoms to form[Li_(6)C_(6)O_(12)F_(3)]_(∞) dou-ble layers.In the structure of KMgLi_(2)(CO_(3))_(2)F,all the[CO_(3)]groups not only parallel to a−b plane but also align in the exactly same orientation in the same double layers.While the[CO_(3)]groups in RbMgLi_(2)(CO_(3))_(2)F are parallel to a−b plane but align in the different orientation.But anyway,their structural characteristic is greatly beneficial to improve the layering-growth habit and eliminate polymorphism of a crystal.Since AMgLi_(2)(CO_(3))_(2)F(A=K,Rb)inherit the beneficial layered structure of SBBO,AMgLi_(2)(CO_(3))_(2)F(A=K,Rb)should have superior optical properties including short ultraviolet(UV)absorption edges and large birefringences.In order to confirm inference,ultraviolet-visible diffuse reflectance spectroscopy data were recorded at room temperature using a powder sample with BaSO_(4) as a standard(100%reflectance)on a PerkinElmer Lambda-950 ultra-violet visible-near infrared spectrophotometer over the scan range 200-2500 nm.The results showed KMgLi_(2)(CO_(3))_(2)F and RbMgLi_(2)(CO_(3))_(2)F exhibited a wide transparency window,>80%,from 200 to 2500 nm,indicating that both of them had short UV cutoff edges b

关 键 词：结构设计 深紫外 氟碳酸盐 双折射晶体 

分 类 号：O76[理学—晶体学]