Cyclen

Cyclen is a macrocyclic tetraamine. Cyclen is the aza analogue of crown ether, used as a precursor for MRI contrast agents, and is an intermediate for the preparation of effective macrocyclic chelates. Cyclen is employed as a structural regulator through interfacial polymerization of polyethleneimine (PEI) and trimesoyl chloride (TMC) to develop polyamide NF membrane with efficient Li+/Mg2+ separation performance. Cyclen has specific cavity structure and exhibits selective coordination properties for Li+ ions[1][2].