HexafluoroarsenateV

Hexafluoroarsenate(V) is an anion with the chemical formula AsF6-. It consists of a central arsenic atom in the +5 oxidation state, surrounded by six fluorine atoms in an octahedral geometry. This anion is a strong oxidizing agent and a relatively weak coordinating anion. It is typically found as a salt with various cations, such as potassium hexafluoroarsenate(V), KAsF6, or silver hexafluoroarsenate(V), AgAsF6.

Hexafluoroarsenate(V) salts are often used in inorganic chemistry due to their stability and their ability to stabilize unusual oxidation states or reactive cations. For instance, the hexafluoroarsenate(V) anion is often employed as a non-coordinating counterion in the synthesis of highly reactive cationic species, as it is less likely to interact with and stabilize these species compared to more coordinating anions like chloride or nitrate. This property makes it valuable in studies of reaction mechanisms and in the preparation of novel chemical compounds.

The preparation of hexafluoroarsenate(V) salts typically involves the reaction of arsenic pentafluoride (AsF5) with a fluoride source or with a metal fluoride. For example, reacting AsF5 with a metal fluoride like KF can yield KAsF6. Due to the reactivity and toxicity of arsenic compounds, handling hexafluoroarsenate(V) and its precursors requires appropriate safety precautions.