In chemistry, a thiyl radical has the formula RS, sometimes written RS^• to emphasize that they are

free radical A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing. Ageing Ailments of unknown cause Biogerontology Biological processes Causes of death Cellular processes Gerontology Life extension Metabo ...

s. R is typically an alkyl or aryl substituent. Because S–H bonds are about 20% weaker than C–H bonds, thiyl radicals are relatively easily generated from

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...

s RSH. Thiyl radicals are intermediates in the

thiol-ene reaction In organosulfur chemistry, the thiol-ene reaction (also alkene hydrothiolation) is an organic reaction between a thiol () and an alkene () to form a thioether (). This reaction was first reported in 1905, but it gained prominence in the late 1990s ...

, which is the basis of some polymeric coatings and adhesives. They are generated by hydrogen-atom abstraction from thiols using initiators such as AIBN: : RN=NR → 2 R^• + N₂ :R^• + R′SH → R′S^• + RH Thiyl radicals are also invoked as intermediates in some biochemical reactions.

References

Free radicals Organosulfur compounds {{organic-chemistry-stub