In organosulfur chemistry, thiosulfinate is a functional group consisting of the linkage R-S(O)-S-R (R are organic substituents). Thiolsulfinates are also named as alkanethiosulfinic (or arenethiosulfinic) acid esters. They are the first member of a family of compounds containing an oxidized disulfide bond. Other members of this family include thiosulfonates, R-SO₂-S-R, a-disulfoxides, R-S(O)-S(O)-R, sulfinyl sulfones, R-S(O)-SO₂-R, and a-disulfones, R-SO₂-SO₂-R, all of which are known. The thiosulfinate group can occur in cyclic as well as acyclic structures.