Part 1 Introduction to macrocycle chemistry: crown ether precursor work Pedersen's discovery of crown ethers Simmons' in-out bicyclic amines Lehn's cryptands cram and carbanions classes of crown ethers and cryptands naturally occurring relatives of crown ethers nomenclature and its problems toxicity of crown ether compounds. Part 2 Syntheses of crowns, cryptands and their relatives: Pedersen's first crowns the ethylencoxy structural unit the template effect early syntheses of crowns syntheses of crown ethers incorporation of aromatic subunits nitrogen-containing macrocycles crown ethers containing sulfur syntheses of cryptands spherands, cavitands, and carcerands. Part 3 Complexation by crowns and cryptands: the extraction technique homogeneous cation binding constants binding dynamics cation transport complexation of organic cations anions. Part 4 Structural aspects of crowns, cryptands, and their complexes: uncomplexed crown and cryptand ligands simple crown ether complexes of metal cations complexes of cryptands crown ether complexes of other ions and molecules podand complexes. Part 5 Applications of crowns and cryptands: solubilization phenomena cation deactivation anion activation - phase transfer catalysis sensors and switching polymeric crown systems membranes and channels chirality, complexation and enzyme models receptor molecules miscellaneous applications and developments the future of crown ether chemistry. Part 6 Additional reading: books crown ethers cryptands, and polyethers monographs on phase transfer catalysis reviews and articles.

Crown Ethers and Cryptands

Von molekularen Wirten und Gästen sowie ihren Komplexen: Nobel-Vortrag

The Na+ or K+ cation−π interaction has been experimentally probed by using synthetic receptors that comprise diaza-18-crown-6 lariat ethers having ethylene sidearms attached to aromatic π-donors. T...

Alkali metal cation-pi interactions observed by using a lariat ether model system.

Comprehensive coordination chemistry of alkali and alkaline earth cations with macrocyclic multidentates: latest position

Although the antibiotics nigericin and lasalocid as first representatives of the naturally occurring ionophores were isolated as early as 1951 from Streptomyces cultures 1), it was only in the late sixties that the function of these membranes affecting compounds as complexing and transporting agents for alkali metal ions was established 2–4). Once their outstanding properties as selective alkali cation carriers had been understood, however, they attracted the attention of numerous investigators, and many details have been learnt about their structures, complex formation and physiological activity. Furthermore, a considerable number of model compounds were synthesized, above all the so-called polyether ligands which did not only help to understand the mechanism of action of the naturally occurring ionophores but also led to the rapid development of phase-transfer techniques in organic chemistry, to mention only one application.

M. Dobler

Papers

Potassium thiocyanate complex of 1,4,7,10,13,16-hexaoxacyclooctadecane