Fluorides of Copper,Silver, Gold,and Palladium

Fluorine, by far the most reactive of the non-metals, is capable of forming a large number of compounds with nearly all other elements (exceptions (so far): He, Ne, and Ar), even under comparatively “mild” reaction conditions. These compounds usually differ markedly from those of the heavier halogens in composition, structure, and chemical and physical properties. Thus, for example, it is generally quite easy to prepare fluorides containing elements in high oxidation states (often their maximum), as in AgF₂, CsAgF₄, PdF₃, CsAuF₆ etc., whereas the corresponding chlorides, bromides or iodides are in many cases (still) unknown. Conversely, the synthesis of fluorides containing these elements in middle or low oxidation states often meets with considerable difficulty, even where it is possible at all, as, e.g., in the case of CuF, AuF, PtF₂, SeF₂. Finally, there are also some examples of compounds MX_n, which with X = F are stable, but with X = Cl are unstable or decompose easily (e.g. CoF₃/CoCl₃, VF₄/VCl₄, PbF₄/PbCl₄, AsF₅/AsCl₅). Consequently, fluorine compounds are of great general interest.