Compounds having the structure, $\ce{RS(=O)2R}$ ($\ce{R} \neq \ce{H}$), e.g. $\ce{C2H5S(=O)2CH3}$ ethyl methyl sulfone.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1369 [Terms] [Paper]