Thiol

In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl (–C–SH or R–SH) group (where R represents an alkane, alkene, or other carbon-containing group of atoms). Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl group of an alcohol), and the word is a portmanteau of "thion" + "alcohol," with the first word deriving from Greek θεῖον ("thion") = "sulfur." The –SH functional group itself is referred to as either a thiol group or a sulfhydryl group.

Quotes

• The most striking characteristic of thiols is their appalling odor. Skunk scent, for instance, is caused primarily by the simple thiols 3-methyl-1-butanethiol and 2-butene-1-thiol. Volatile thiols such as ethanethiol are also added to natural gas and liquefied propane to serve as an easily detectable warning in case of leaks.
  • John McMurry, Organic Chemistry 8th ed. (2012), Ch. 18. Ethers and Epoxides; Thiols and Sulfides

• Thiols can be oxidized by Br₂ or I₂ to yield disulfides (RSSR′). The reaction is easily reversed, and a disulfide can be reduced back to a thiol by treatment with zinc and acid.
  • John McMurry, Organic Chemistry 8th ed. (2012), Ch. 18. Ethers and Epoxides; Thiols and Sulfides