|Preferred IUPAC name
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||308.371 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
21-Crown-7 is an organic compound with the formula [C2H4O]7 and the IUPAC name of 1,4,7,10,13,16,19-heptaoxacycloheneicosane. Like other crown ethers, 21-crown-7 functions as a ligand for some metal cations with a particular affinity for caesium cations. The dipole moment of 21-crown-7 varies in different solvents and under different temperatures.