What is "sulfonyl"

alt. (context American spelling chemistry English) the bivalent radical or functional group -SO₂- n. (context American spelling chemistry English) the bivalent radical or functional group -SO₂-

A sulfonyl group can refer either to a functional group found primarily in sulfones or to a substituent obtained from a sulfonic acid by the removal of the hydroxyl group similarly to acyl groups. Sulfonyl groups can be written as having the general formula R-S(=O)-R', where there are two double bonds between the sulfur and oxygen.

Sulfonyl groups can be reduced to the hydrocarbon with lithium aluminium hydride (LiAlH).

In inorganic chemistry, when the group -S(=O)- is not connected to any carbon atoms, it is referred to as sulfuryl.