In the S2F10 molecule, the oxidation state of each sulfur atoms is +5, but their valency is 6 (they are hexavalent).

It is a colorless liquid with a burnt match smell similar to sulfur dioxide.

It is produced by the electrical decomposition of sulfur hexafluoride (SF6)—an essentially inert insulator used in high voltage systems such as transmission lines, substations and switchgear.

In the presence of excess chlorine gas, S2F10 reacts to form sulfur chloride pentafluoride (SF5Cl): The analogous reaction with bromine is reversible and yields SF5Br.

[9] S2F10 was considered a potential chemical warfare pulmonary agent in World War II because it does not produce lacrimation or skin irritation, thus providing little warning of exposure.