Oxoanions

Part of speech: noun

Definitions

1. Polyatomic ions consisting of a central atom bonded to one or more oxygen atoms carrying a net negative charge; often found in inorganic chemistry as fundamental species in salts or acids; characterized by their variable oxidation states and structures
2. Negatively charged ions formed by a central element linked to oxygen atoms, common in coordination chemistry and environmental compounds; these species exhibit diverse geometries and are important in redox reactions and acid-base chemistry
3. Ions composed of a central nonmetal or metal atom covalently attached to oxygen atoms resulting in an overall negative charge; essential in mineralogy and biogeochemical cycles; their properties depend on the oxidation number of the central atom and number of oxygen atoms attached

Etymology: Oxoanions are a compound of two older English coinages. "Anion" was introduced by Michael Faraday in the 1830s, when he needed a name for the ion that travels toward the anode during electrolysis, and he built it from the Greek "ion," meaning "going." The "oxo-" part is a much more recent piece of chemical shorthand, drawn from "oxygen," the element whose name itself was coined by Antoine Lavoisier from Greek roots meaning "acid-former." So "oxoanion" literally means something like "oxygen-containing anion." The "-o-" that links the two parts is a standard connecting vowel in chemical naming, the same device that appears in words like "carbonate" and "sulphate" in chemical nomenclature. The surprising twist is that the Greek word behind "oxygen" does not describe oxygen's chemistry well at all. Lavoisier believed that oxygen was the essential element of all acids, an idea that later proved mistaken, so the name preserved a theory that chemists abandoned. Oxoanions, in contrast, really do form the acids that give the theory its name.

Synonyms: oxo ions, oxoacid anions, oxygen-containing anions, acid radicals, oxoacid radicals