Tetraoxygen difluoride
Tetraoxygen difluoride is an inorganic chemical compound of oxygen, belonging to the family of oxygen fluorides. It consists of two OF units bound together with a weak O-O bond, and is the dimer of the OF radical. Preparation. Tetraoxygen difluoride can be prepared in two steps. In the first step, a photochemically generated fluorine atom reacts with oxygen to form the dioxygen fluoride radical. This radical subsequently undergoes dimerization, entering an equilibrium with tetraoxygen difluoride at temperatures under −175 °C: At the same time, the dioxygen fluoride radicals decompose into dioxygen difluoride and oxygen gas, which  shifts the above equilibrium with OF to the left. Properties. Tetraoxygen difluoride is dark red-brown as a solid and has a melting point around −191 °C. It is a strong fluorinating and oxidizing agent, even stronger than dioxygen difluoride, so that it can, for example, oxidize Ag(II) to Ag(III) or Au(III) to Au(V). This process creates the corresponding anions AgF and AuF. With non-noble substances this oxidation can lead to explosions even at low temperatures. As an example, elemental sulfur reacts explosively to form sulfur hexafluoride even at −180 °C. Similar to [OF] or OF, tetraoxygen  difluoride tends to form salts with the oxygenyl cation O when it reacts with fluoride acceptors such as boron trifluoride (BF). In the case of BF, this leads to the formation of O•BF: Similarly, for arsenic pentafluoride it reacts to create OAsF.