The performance of selenium dioxide

Selenium dioxide is a polar molecule, with the dipole moment pointed from the midpoint of the two oxygen atoms to the selenium atom. Solid Selenium dioxide is a one-dimensional polymer, the chain consisting of alternating selenium and oxygen atoms. Each Se atom, which is pyramidal, bears a terminal oxide group. The relative stereochemistry at Se alternates along the polymer chain . The solid sublimes readily. The vapour has an odour resembling horseradish sauce and can burn the nose and throat on inhalation. Gaseous selenium dioxide adopts a bent structure very similar to that of sulfur dioxide. Dissolution of SeO2 in selenium oxydichloride give the trimer [Se(O)O]3. Whereas SO2 tends to be molecular and SeO2 is a one-dimensional chain, TeO2 is a cross-linked polymer.
Selenium dioxide is considered an acidic oxide: it dissolves in water to form selenous acid. Often the terms selenous acid and selenium dioxide are used interchangeably. It reacts with base to form selenite salts containing the SeO2−3 anion.