Two　metal　iodates.　(NaIO3H2O)-H-.　and　In(IO3)(3),　have　been　prepared　by　hydrothermal　reactions　at　170　degrees　C.　The　X-ray　structural　analysis　showed　that　(NaIO3H2O)-H-.　crystallizes　in　a　inonoclinic　space　group　C2　with　a　=　14.175(3)　angstrom,　b　=　3.6688(3)　angstrom,　c　=　9.666(1)　angstrom,　beta　=　124.41　(1)degrees,　Z　=　4　and　In(IO3)(3)　in　a　hexagonal　group　P6(3)　with　a　=　9.5463(8)　angstrom,　c=　5.2745(8)　angstrom,　Z　=　2.　(NaIO3H2O)-H-.　represents　anew　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)　S　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.　(c)　2005　Elsevier　B.V.　All　rights　reserved.