Merkaptánok

Merkaptánok, also known as thiols, are a class of organosulfur compounds with the general formula R-SH, where R is an alkyl or aryl group and SH is the thiol functional group. They are structurally similar to alcohols, with the oxygen atom replaced by a sulfur atom. Merkaptánok are often characterized by their strong, unpleasant odors, which can be detectable at very low concentrations. This distinctive smell is the reason why mercaptans are deliberately added to natural gas and propane to act as odorants, allowing leaks to be easily detected.

The sulfur atom in the thiol group is larger and less electronegative than oxygen, which influences the chemical properties of mercaptans. The S-H bond is weaker and more polarizable than the O-H bond in alcohols. This makes thiols more acidic than alcohols, although still weak acids. They can participate in various chemical reactions, including oxidation to disulfides (R-S-S-R), which are important in protein structure. Mercaptans also form salts called thiolates with strong bases.

Naturally occurring mercaptans are found in various biological sources, including amino acids like cysteine and methionine, and in volatile compounds produced by some plants and animals, contributing to their characteristic smells. Industrially, mercaptans are used as intermediates in the synthesis of pharmaceuticals, pesticides, and polymers. They also find applications as antioxidants and as chain transfer agents in polymerization processes.