Sulfone is the general name for compounds formed by the combination of sulfonyl and hydrocarbyl, of which the general formula is R-SO2-R. The hydrocarbyl groups (R) can be identical or different, such as dimethyl sulfone (CH3 • SO2 • CH3), ethyl phenyl sulphone (C6H5 • SO2 • C2H5), diethyl sulfone, diphenyl sulfone, sulfolane, bisphenol S, etc. The sulfur in sulfones is of high valence; and sulfone is a stable crystalline organic compound which can’t be reduced into R2S. Sulfolane, dimethyl sulfone and bisphenol S are the most important sulfones in the industry. Sulfone is generally colorless and odorless stable solid. Lower carbon sulfone is soluble in water and most organic solvents. Sulfone can be prepared generally by the oxidation of thioether, the alkylation of sulfonate, the Diels-Alder reaction of sulfur dioxide or the reaction of aromatic hydrocarbons with sulfoxide chloride, etc.

Sulfone is widely used in pharmaceutical, plastics and basic organic synthesis industry. For example, solasulfone and dapsone are drugs for leprosy; bisphenol A polysulfone is a kind of plastic with excellent properties and sulfolane is an excellent solvent which can be used to clean industrial gases such as the removal of carbon dioxide and hydrogen sulfide; it’s also used as a solvent in the polymerization of acrylonitrile as well as in the extraction of aromatics from petroleum. Some sulfones have sedative and hypnotic effects, but with side effects. In addition to a heat resistance, oxidation resistance and light stability of bisphenol S, the hydroxyl in it has strong acidity because of the strong electron-withdrawing of the sulfonyl. Bisphenol S is mainly used as a fixative as well as the material of leather tanning agents, dyes, heat-resistant engineering plastics and crosslinking agents. It also can be used as a substitute for bisphenol A as the raw material of polycarbonate, epoxy resin, polyester resin and phenol resin.

Sulfoxide is the general name for compounds formed by the combination of sulfinyl and hydrocarbyl (R), such as dimethyl sulfoxide, diethyl sulfoxide, benzyl phenyl sulfoxide. The oxygen atom in sulfoxide is in an anion state with a strong polarity and a strong oxidizability. Sulfoxides may be optically active. They are solid at low temperatures and generally soluble in water, alcohol and ether. Sulfoxide can be reduced into sulfide, oxidized into the sulfone and salified with nitrate. It can be prepared generally by the oxidation of sulfide or the Friedel-Crafts reaction of an aromatic hydrocarbon with thionyl chloride.

Sulfoxide can take part in many important reactions.
1, The α-carbanion in sulfinyl can easily react with haloalkane, carbonyl compounds and olefins due to its high reactivity;
2, Sulfoxide along with acid anhydride can induce the Pummerer rearrangement;
3, Olefins and sulfinic acid can be generated after the thermal decomposition of sulfoxide with a β site containing hydrogen.