Used as a phase-transfer catalyst in organic synthesis, facilitating reactions between reagents in different phases by transferring ions into organic solvents. Commonly applied in methylation processes where it serves as a source of methyl groups under mild conditions. Also utilized in the preparation of fine chemicals and pharmaceuticals due to its high solubility and reactivity in non-aqueous environments. Shows utility in electrochemical applications, including as an electrolyte component in certain fuel cells and sensors. Its low thermal stability can be advantageous in controlled decomposition processes to release carbon dioxide and trimethylamine.