Anionit

Anionit is a term used in theoretical chemistry to denote a hypothetical monovalent anion. It has no verified chemical species by that name in peer‑reviewed literature, and there is no confirmed synthesis or isolation. In model studies, anionit is described as a negatively charged species whose charge is delocalized over a framework of ligands or lattice sites, potentially formed from a central atom surrounded by electronegative ligands in an overall −1 charge. The exact composition and geometry are intentionally variable in order to explore how a single negative charge can be stabilized in solid‑state lattices or solvated clusters.

In proposed models, anionit is predicted to be highly reactive with cations, capable of forming salts with alkali and alkaline‑earth metals. Stability depends on lattice energy, solvent, counterions, and temperature. Anionit is often described as a weakly coordinating anion with a large coordination environment and substantial polarizability; its optical and electronic properties are shown to depend on the substituents used in the model.

Occurrence and uses: There is no confirmed natural occurrence of anionit. It appears in theoretical papers and in science fiction as an example of an unusual monoanion. In computational chemistry, it serves as a test case for charge localization, stability of monoanions, and the behavior of highly delocalized charge carriers in extreme environments.

Etymology: The name blends "anion" with the suffix -it, following a common convention in fictional and speculative chemical nomenclature.