Trimethylsulfonium

Trimethylsulfonium refers to the chemical cation with the formula [(CH3)3S]+. It is the conjugate acid of trimethylsulfonium hydroxide. This cation is characterized by a central sulfur atom bonded to three methyl groups and carrying a positive charge. Trimethylsulfonium salts are often encountered in organic chemistry. A common example is trimethylsulfonium iodide, [(CH3)3SI]. These compounds can be synthesized through the reaction of dimethyl sulfide with methyl halides. Trimethylsulfonium salts are known for their use as methylating agents, although they are generally less reactive than other common methylating agents like methyl iodide or dimethyl sulfate. They can also act as precursors in the synthesis of sulfur-containing organic compounds. In some instances, trimethylsulfonium hydroxide, [(CH3)3SOH], has been investigated as a milder and less toxic alternative to tetrabutylammonium hydroxide in phase-transfer catalysis. The stability of the trimethylsulfonium cation is influenced by the nature of the accompanying anion.