Used primarily as a phase-transfer catalyst in organic synthesis, facilitating reactions between reagents in different phases by transferring ions into organic solvents. It is also employed in electrochemistry as a supporting electrolyte due to its high solubility and stability in polar solvents. In neuroscience research, it acts as a potassium channel blocker, helping to study ion channel function in nerve cells. Additionally, it finds use in the preparation of conductive materials and ionic liquids for specialized industrial applications.