Cryptand
In chemistry, cryptands are a family of synthetic, bicyclic and polycyclic, multidentate ligands for a variety of cations. The Nobel Prize for Chemistry in 1987 was given to Donald J. Cram, Jean-Marie Lehn, and Charles J. Pedersen for their efforts in discovering and determining uses of cryptands and crown … See more The most common and most important cryptand is N[CH2CH2OCH2CH2OCH2CH2]3N; the systematic IUPAC name for this compound is 1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane. … See more Cation binding The three-dimensional interior cavity of a cryptand provides a binding site – or host – for "guest" ions. The complex between the cationic guest … See more • Clathrate • Clathrochelate • Cryptophane • Cyclodextrin See more Cryptands enjoy no commercial applications but are reagents for the synthesis of inorganic and organometallic salts. Although more expensive and more difficult to prepare than crown ethers, cryptands bind alkali metals more strongly. They are especially … See more • IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "cryptand". doi:10.1351/goldbook.C01426 • Lee, J.D. (1991). … See more WebCryptand In chemistry, cryptands are a family of synthetic, bicyclic and polycyclic, multidentate ligands for a variety of cations. The Nobel Prize for Chemistry in 1987 was …
Cryptand
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WebMar 12, 2024 · Cryptand 5 did not complex viologen derivatives 11 – 13 to an extent detectable by 1 H NMR. We attribute the lack of complexation between viologen derivatives and 5 to its lack of conformational flexibility … WebHans Joachim Gais, Juergen Mueller, Juergen Vollhardt, Hans J. Lindner: Structure of a free, unassociated alkyl-substituted .alpha.-sulfonyl carbanion: isolation and x-ray crystal structure analysis of the inclusive lithium cryptate (Me2CSO2Ph)(Li.cntdot.[2.1.1]cryptand). In: Journal of the American Chemical Society. Band 113, Nr.
Web1 Laboratory of Plant Stress Biology and Biotechnology, Division of Crop Genetics and Breeding, Crop Research Institute, Drnovská 507/73, 16106 Prague, Czech Republic WebJul 12, 2024 · Cryptand hosts for encapsulated chloride ions have developed from the first reported example of a cryptand anion host in 1968 (1) to the triazole-based cryptand reported by Liu et al. (6).Only several key cryptands have been selected, including widely used amines (1 to 3), an amide (4), a mixed calixpyrrole-amide (5), and a triazole …
WebOct 22, 2024 · 14) R. Brachvogel, H. Maid, M. von Delius NMR Studies on Li +, Na + and K + Complexes of Orthoester Cryptand o-Me 2-1.1.1 International Journal of Molecular Sciences 2015, 16, 20641-20656 13) R. Brachvogel, F. Hampel, M. von Delius Self-assembly of dynamic orthoester cryptates Nature Communications 2015 , 6 , 7129 WebMar 26, 2024 · Cryptands are named x.y.z.-crypt after the number of oxygen binding sites in each of the chains connecting the two amine groups. Thus 2.2.2-crypt consists of two …
WebCryptands were introduced by Jean-Marie Lehn in 1969 as cage-shaped selective ligands for alkali and alkaline-earth metal ions, which lie at the heart of supramolecular …
WebAbstract. The design of supramolecular hosts for anions began with simple diaza bicycles, named katapinands, and has evolved over the last 40 years to a number of elegantly designed receptors capable of binding many different anions. About the same time the term cryptand appeared in reference to another bicyclic compound that was selective for ... how many newtons in a newton meterWebA simple definition of a cryptand is a bicyclic (or polycyclic) ligand.1 This definition was derived from Lehn's observations of the behavior of cryptands with alkali metals. Lehn noticed that a 3D structure with flexible linkers having donor groups capable of encapsulating cations would be analogous to the first solvation shell of cations. how big is a bathroom sinkWebA study of complex formation between the octa-substituted zinc porphyrinate with the cryptand showed that the stability of the 1:1 complexes (79-Cr1) that are formed as a result is much higher than that of the similar zinc tetraphenylporphyrinate complex with the cryptand (82-Cr1) . Evidently, the intramolecular complexing cavity formed by the ... how big is a beach hutWebFeb 21, 2006 · The complexes are commonly named cryptates 23 First discovered by Donald Cram, spherands are another group of macrocyclic cation hosts, synthesized … how big is a beagleWebMay 25, 2024 · The acid–base equilibria of cryptand[2.2.2] in aqueous solutions have been studied quite well [3–10]. The constants of protonation of cryptand[2.2.2] in non-aqueous and mixed solvents are known for 95% methanol , 100% methanol , and water–ethanol solvents of variable composition . In this work, we studied the effect the composition of ... how many newtons is 1 poundWebFeb 2, 2024 · A solution of 1.5 mL (1.0 mL acetonitrile, 0.5 mL water) containing cryptand 222 (15 mg of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) and 3.0 mg … how many newtons is 100gWebJul 4, 2024 · Cryptands are cages (also of basic nature), they also develop acid base interactions towards electrodeficient counterparts, but they interact each other in two or more planes depending on the... how big is a beacon