Mao Fei-Fei, Hu Chun-Li, Li Bing-Xuan, Mao Jiang-Gao
University of the Chinese Academy of Sciences , Beijing 100039, P. R. China.
Inorg Chem. 2017 Nov 20;56(22):14357-14365. doi: 10.1021/acs.inorgchem.7b02508. Epub 2017 Nov 9.
Partial substitution of iodate anions in La(IO) by OH or NO anion led to acentric La(IO)(OH) and chiral La(IO)(NO). The structure of La(IO)(OH) can be seen as a complex three-dimensional (3D) network composed of two-dimensional [La(IO)(OH)] cationic layers that are further bridged by remaining iodate anions, or alternatively as a 3D network composed of one-dimensional [La(IO)(OH)] cationic columns being further interconnected by additional iodate anions, while the structure of La(IO)(NO) can be seen as a novel 3D structure with planar NO groups serving as linkage between the [La(IO)] triple layers. Compared to La(IO), both compounds show considerably wide band gaps and enhanced thermal stability. La(IO)(NO) shows a moderate second harmonic generation (SHG) response of ∼0.6 times that of KDP (KHPO), a wide band gap of 4.23 eV, and a high LDT value (22 × AgGaS). Optical property measurements, thermal analysis, as well as theoretical calculations on SHG origin, were performed. It can be deduced that partial substitution of iodate anions can be a facile route to design new noncentrosymmetric metal iodates with novel structure and potential application.
用OH或NO阴离子部分取代La(IO)中的碘酸根阴离子，得到了非中心对称的La(IO)(OH)和手性的La(IO)(NO)。La(IO)(OH)的结构可以看作是由二维[La(IO)(OH)]阳离子层组成的复杂三维（3D）网络，这些阳离子层通过剩余的碘酸根阴离子进一步桥连，或者也可以看作是由一维[La(IO)(OH)]阳离子柱组成的3D网络，这些阳离子柱通过额外的碘酸根阴离子进一步相互连接，而La(IO)(NO)的结构可以看作是一种新颖的3D结构，其中平面NO基团作为[La(IO)]三层之间的连接。与La(IO)相比，这两种化合物都表现出相当宽的带隙和增强的热稳定性。La(IO)(NO)表现出中等的二次谐波产生（SHG）响应，约为KDP（KHPO）的0.6倍，宽带隙为4.23 eV，以及高的激光损伤阈值值（22×AgGaS）。进行了光学性质测量、热分析以及关于SHG起源的理论计算。可以推断，碘酸根阴离子的部分取代可以是设计具有新颖结构和潜在应用的新型非中心对称金属碘酸盐的简便途径。
