crown ether

== English == === Etymology === So called because its structure is shaped like a crown (the royal headgear). === Noun === crown ether (plural crown ethers) (organic chemistry) any of a class of macrocyclic compounds containing repeat units of -CH2CH2O- (organic chemistry) any similar compound containing atoms of nitrogen, sulfur, phosphorus or silicon instead of, or as well as, oxygen === See also === cryptand lariat ether