merkaptaner

Merkaptaner (commonly called mercaptans or thiols in English) are an organic functional class characterized by a sulfhydryl group (–SH) bound to an alkyl or aryl residue (general formula R–SH). The preferred IUPAC name for the group is "thiol." The common name "mercaptan" derives from historical observations that these compounds readily form strong complexes with mercury.

Thiols are typically more polar than hydrocarbons but less able to hydrogen-bond than comparable alcohols, and they often have lower boiling points than the corresponding alcohols. Many low-molecular-weight mercaptans possess very strong, unpleasant odors detectable at extremely low concentrations, a property exploited commercially: ethanethiol and similar compounds are added as odorants to otherwise odorless natural gas to aid leak detection.

Chemically, the sulfur atom makes thiols nucleophilic and easily oxidized; typical reactions include deprotonation to form thiolate anions (R–S–), alkylation, and oxidation to disulfides (R–S–S–R). These reactions underpin their roles in organic synthesis, polymer chemistry (including vulcanization), and the manufacture of pharmaceuticals and agrochemicals.

Biologically, thiol groups occur in amino acids (cysteine) and cofactors (glutathione), where they serve in redox chemistry, metal binding, and enzyme catalysis. Safety concerns with mercaptans center on strong odors, volatility, flammability, and potential toxicity at high concentrations. Environmental and industrial controls include odor management, monitoring, and oxidation or adsorption treatments to mitigate releases.