The Crystal Growth Of Iodate Nonlinear Optical Materials And Analyses Of Their Structures

Because the presence of electron lone pair, the iodate group may induce the compound to form the asymmetric structure. These polar iodates may exhibit a variety of technologically important properties including ferreoelectricity, piezoelectricity, pyroelectricity and nonlinear optical behavior.In this work six new metal iodates have been prepared by hydrothermal method at 170℃, and their crystal structures have been determined. The X-ray single-crystal structural analysis showed that NaIO3·H2O crystallizes in a monoclinic space group C2 with a = 14.175(3)?, b = 3.6688(3)?, c =9.666(1)?,β= 124.41(1)°, Z = 4. It represents a new structure type and it can be viewed as a layered compound consisting of two-dimensional layers of edge-sharing NaO7 monocapped octahedra that are capped by IO3- group. Al(IO3)3 crystallizes in a non-centrosymmetric group P63 with a = 9.003(1)?, c =5.2406(5)?, Z = 2 . Al(IO3)3 is characterized by the slightly distorted AlO6 octahedra that are bridged by IO3- group giving rise to a 3D polar network. Ga(IO3)3 crystallized in a polar space group P63, with cell parameters a = 9.0924(5)?, c =5.2862(8)?, V=378.47(6)? 3, Z = 2. In the structure of Ga(IO3)3, each Ga3+ ion is coordinated to six O atoms in a slightly distorted octahedral geometry. GaO6 octahedra are arranged around 63 screw axes and bridged by the IO3- group leading to an overal three-dimensional (3D) framwork. In(IO3)3 crystallizes in a hexagonal group P63 with a = 9.5463(8)?, c =5.2745(8) ?, Z = 2. It is a new compound containing slightly distorted InO6 octahedra that are bridged by IO3- groups giving rise to a three-dimensional polar net work. Ce(IO3)3 is a new polymorph, space group P21/n, with a = 13.56(2)?, b = 8.565(9)?, c =7.24(12)?,β= 99.7(3)°, V = 826(2)? 3. The crystal structure of Ce(IO3)3 consists of one-dimensional chains of edge-sharing CeO9 polyhedra which are crosslinked into two-dimensional layers through bridging IO3- groups. The layers are held together via long I…O contacts, resulting in an extented three-dimensional network. Nd(IO3)3 presented here is a new polymorph which crystallized in a monoclinic space group P21/n with a = 8.859(1)?, b = 5.9296(5) ?, c =15.301(3) ?,β= 96.95(1)°, Z = 4. The crystal structure of Nd(IO3)3 consisits of 1D chains of edge-sharing NdO9 polyhedra, which...