Crown and Lariat Ethers

Abstract

AbstractCrown ethers first came to prominence in the late 1960s through the pioneering work of Charles Pedersen. The discovery that they bind cations based on complementarity between the crown ether cavity and the size of the cation has been a driving force in macrocyclic and supramolecular chemistry ever since. Many derivatives have been synthesized, including those with side arms known collectively as lariat ethers, and their cation selectivity used in molecular sensors. The history of crown and lariat ethers is discussed together with their syntheses, structural and binding evidence for size selectivity, and their industrial and clinical applications. Crown and lariat ethers have found use as phase‐transfer catalysts, modifiers for chromatographic media, sensors for numerous chemical species, critical analyte detectors, and can even enhance insecticide activity. They have been used to probe important biological phenomena, including enzyme specificity, the nature ofin vivocation‐π interactions in proteins and transmembrane ion transport, through the synthesis of model compounds.