polonide

Polonide is the term used in inorganic chemistry to describe compounds containing the polonide ion, Po2−, the polonium analogue of sulfide, selenide, and telluride. In these salts, polonium exists effectively in the −II oxidation state and is balanced by more electropositive cations such as alkali metals or alkaline earth metals. The concept also corresponds to the Po2− ion itself, which is the fundamental building block in polonide chemistry.

Polonides are typically binary compounds formed by direct reaction of polonium with suitable metals. Common examples include alkali polonides such as sodium polonide (Na2Po) and potassium polonide (K2Po), as well as alkaline-earth polonides like calcium polonide (CaPo), strontium polonide (SrPo), and barium polonide (BaPo). The precise stoichiometry depends on the charges of the participating cations. Polonides can also be produced by solid-state reactions at elevated temperatures in controlled atmospheres, or by reactions of polonium with pre-formed polonide precursors.

Properties of polonides are predominantly ionic and solid-state in nature. They tend to be highly radioactive due to the polonium component, and their stability can be sensitive to air and moisture. Because polonium is an α-emitter with significant radiotoxicity, polonide compounds are mainly of interest within specialized research settings for fundamental studies of polonium chemistry and radiochemistry.

Safety and handling: polonides require strict radiological controls, specialized facilities, and trained personnel. They are not commercially or publicly available in any ordinary sense and are used only under appropriate regulatory oversight in research laboratories.