What is "tetrafluoroborate"

n. (context inorganic chemistry English) The anion BF₄^- and any salt containing this ion; they have a number of uses in synthetic chemistry

Tetrafluoroborate is the anion BF. This tetrahedral species is isoelectronic with tetrafluoromethane, CF and tetrafluoroammonium NF, and is valence isoelectronic with many stable and important species including the closely related anion perchlorate, ClO. It arises by the reaction of fluoride salts with the Lewis acid BF, treatment of tetrafluoroboric acid with base, or by treatment of boric acid with hydrofluoric acid.