Hydrothermal synthesis and crystal structures of two NLO compounds, NaIO3·H2O and In(IO3)3

Two metal iodates, NaIO3·H2O and In(IO3)3, have been prepared by hydrothermal reactions at 170 °C. The X-ray structural analysis showed that NaIO3·H2O crystallizes in a monoclinic space group C2 with a = 14.175(3) Å, b = 3.6688(3) Å, c = 9.666(1) Å, β = 124.41(1)°, Z = 4 and In(IO3)3 in a hexagonal group P63 with a = 9.5463(8) Å, c = 5.2745(8) Å, Z = 2. NaIO3·H2O 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− groups, while In(IO3)3 is a new compound containing slightly distorted InO6 octahedra that are bridged by IO3− groups giving rise to a three-dimensional polar network. Both compounds crystallize in non-centrosymmetric, chiral space groups.