Molecular Design of Crown Ethers. VII. Syntheses and Cation Selectivities of Unsubstituted 12- to 16-Crown-4
نویسندگان
چکیده
منابع مشابه
Molecular recognition and conductance in crown ethers.
Crown ethers have the remarkable property of recognizing and binding specific metal cations in complex mixtures. We propose to combine molecular recognition with molecular electric conductance. The question we address is: can the event of binding a cation be sensed by a change in conductance? Specifically, we study a short molecular wire (MW) containing a crown-6 molecule connected via sulfur a...
متن کاملLiquid crystalline crown ethers.
In this chapter, a comprehensive review over the entire reserarch on liquid crystalline crown ethers since their discovery will be given. Monomeric and polymeric molecules containing crown ethers as well as aza crown ethers, thia crown ethers and crown ethers with several different heteroatoms will be presented. Liquid crystallinity is, in most cases, caused by the substituents attached to the ...
متن کاملThe discovery of crown ethers.
The discovery of the crown ethers stemmed from efforts to control the catalytic activity of vanadium and copper by complexation with multidentate ligands. The first crown ether, 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclo-octadeca-2,11-diene, was obtained in 0.4% yield during an attempt to prepare a phenolic ligand from catechol and bis(2-chloroethyl)ether. This compound, which complexed with...
متن کاملSynthesis and structure of [ K – ( 12 - crown - 4 ) 2 ] 2 [ K – ( 12 - crown - 4 ) ] 2 [ Sn 9 ] · 4 en †
The new compound [K–(12C4)2]2[K–12C4]2[Sn9]·4en (1), where 12C4 is 12-crown-4 polyether, was crystallized from an ethylenediamine solution of an intermetallic precursor with nominal composition K4Li2Sn8. The structure of the compound (orthorhombic, Cmca, a = 21.763(4), b = 16.030(3), c = 51.85(1) Å, Z = 8) contains isolated deltahedral clusters of [Sn9]4−. The clusters are of Cs symmetry and ar...
متن کاملMagnetic nanoparticle-supported crown ethers.
Magnetic nanoparticle (MNP)-supported crown ethers were successfully prepared and evaluated as catalysts for solid-liquid phase-transfer reactions; the catalytic activities of the MNP-supported crown ethers were not inferior to those of non-supported crown ethers; after the reactions, the catalysts could be readily separated using an external magnet and reused without significant loss of cataly...
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ژورنال
عنوان ژورنال: Bulletin of the Chemical Society of Japan
سال: 1990
ISSN: 0009-2673,1348-0634
DOI: 10.1246/bcsj.63.3044