18-crown ether-6, also known as crown ether, belongs to macrocyclic ether organic compounds, the main use is high-efficiency phase transfer catalyst for fine organic synthesis, complexing agent, precious metal and rare earth element separation and extraction of extract Chemicalbook extractor. It can be used for ion enrichment, separation and masking in chemical analysis, and can also be used in medicine, biochemistry and electronics industry as ion conductive materials and liquid crystal display element production materials.