Tetramethylammonium chloride

Tetramethylammonium chloride (CAS 75-57-0) is a quaternary ammonium salt commonly abbreviated as TMAC or TMACL. It carries no assigned E-code and is supplied as a hygroscopic crystalline powder. Procurement teams may encounter it under the synonyms TMA chloride or tetramethyl ammonium chloride across supplier catalogues and technical datasheets.

In pharmaceutical synthesis, TMAC functions as a phase-transfer catalyst, accelerating reactions between reagents in immiscible phases by shuttling anions across the interface. In polymer processing, it acts as a catalyst in epoxy curing systems and polymerisation reactions. Life science laboratories also use it in nucleic acid hybridisation buffers, where its ionic strength reduces non-specific binding.

TMAC is available in technical and high-purity grades, with the latter meeting REACH registration requirements for supply within the EU. It is classified under HS code 29239000 for customs purposes. Standard packaging formats include multi-layer moisture-barrier bags and drums suited to the compound's hygroscopic nature.