Paradoxes and paradigms: on ambisaline ions of oxygen, fluorine, and related oxyfluorides

In this review, we discuss different ions of oxygen and fluorine and related oxyfluorides and isoelectronic species from the viewpoint of their potential ambisaline character, defined as a property of species X so that both X+ and X− may both be found in isolable salts. The term is applied to the ions as well as to the neutral precursor. Reactivity versus stability, reported and plausible synthetic approaches of well-established and probable species are discussed from the perspective of thermochemistry.