Gold(V) fluoride

This fluoride compound features gold in its highest known oxidation state.

This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine.

It is the only known dimeric pentafluoride, although sulfur can form disulfur decafluoride; other pentafluorides are monomeric (P, As, Sb, Cl, Br, I), tetrameric (Nb, Ta, Cr, Mo, W, Tc, Re, Ru, Os, Rh, Ir, Pt), or polymeric (Bi, V, U).

[1] In the gas phase, a mixture of dimer and trimer in the ratio 82:18 has been observed.

Gold pentafluoride is the strongest known fluoride ion acceptor, exceeding the acceptor tendency of even antimony pentafluoride; and is also the strongest known Lewis acid.

Gold(V) fluoride
Gold(V) fluoride