mercaptaner

Mercaptaner, commonly known as mercaptans, are a class of organosulfur compounds that contain the sulfhydryl group (-SH) bonded to a carbon atom. The general formula is R–SH, where R is an alkyl or aryl group. In modern chemistry these compounds are called thiols; the term mercaptan remains common in industry and in many languages.

The -SH group confers distinctive chemical behavior: thiols are weak acids with a pKa around 10 and readily oxidize to disulfides (R–S–S–R). They are typically volatile and have strong, often unpleasant odors, with methanethiol (CH3SH) and ethanethiol (C2H5SH) as notable examples. Some thiols contribute to flavors and fragrances, while others are primarily valued for their reactivity as intermediates in synthesis.

Uses and significance include odorization of natural gas and propane to enable leak detection, frequently using tert-butyl mercaptan or blends of mercaptans. They also serve as versatile intermediates in the manufacture of polymers, rubber additives, agrochemicals, and pharmaceuticals. Some thiols occur naturally in foods and beverages and contribute to aroma profiles.

Safety and handling: Mercaptans are flammable and can irritate the skin, eyes, and respiratory tract at sufficient exposures. Odor can provide a warning, but olfactory fatigue may occur. Handling requires adequate ventilation, proper containment, and appropriate personal protective equipment. They can form reactive byproducts and should be stored away from oxidizers.

Production and regulation: Industrial thiols are produced by methods such as hydrothiolation of alkenes and related routes. Due to their odor and hazard profiles, their use is subject to safety guidelines and occupational exposure limits, with odorization levels carefully controlled to ensure detectability without excessive exposure.