Iodate is pyramidal in structure. The O-I-O angles range from 105-97°, somewhat smaller than the O-Cl-O angles in chlorate.
Iodate is one of several oxyanions of iodine. It participates in several redox reactions, e.g. the iodine clock reaction. Iodate show no tendency to disproportionate to periodate and iodide, in contrast to the situation for chlorate.
Iodate is reduced by sulfite:
Iodate oxidizes iodide:
Similarly chlorate oxidizes iodide:
Iodate is unusual in that it forms a strong hydrogen bond with its parent acid:
The anion H[IO3]2- is referred to as biiodate.
Minerals containing iodate are found in the caliche deposits of Chile. The most important iodate minerals are lautarite and brüggenite, but also copper-bearing iodates (e.g., salesite) are known.
Thioethers can be oxidized to sulfoxides by periodate, and periodate is reduced to iodate