Calixcrowns: synthesis and properties

A perspective to resorcinarene crowns

“…Since the previous review on calix [n]arene crowns mentioning also resorcinarene crowns published in 2008, 7 a lot of progress has been accomplished with the latter group of supramolecular hosts. As their structural characteristics are already well defined, the basic synthesis methods are explored and the primary application studies have been promising it is likely that study of resorcinarene crowns will continue with the aim of creating yet larger functional nanosized assemblies as well as potential applications, for example, in the fields of transportation and separation.…”

“…6 The crown ether moieties have subsequently been employed as a part of a structure of other supramolecular hosts such as calix [4]arenes to form a group of calix[n]crowns, which have shown to exhibit remarkable ionophoric properties as hosts for alkali and alkali earth metals as well as tertiary amines. 7 The subclass of calixarene family, namely calix[4]resorcinarenes, or simply resorcinarenes share lot of common features with their close relatives, calix[4]arenes. 8 Therefore resorcinarenes provide a good but relatively little explored alternative for crown ether functionalization with sufficiently different properties to calix crowns in respect to binding properties and structural features.…”

Cation binding resorcinarene bis-crowns: the effect of lower rim alkyl chain length on crystal packing and solid lipid nanoparticles

“…18 Depending on the number of 65 oxygen donors and thus the length and geometry of the crown bridge, calixcrowns have very good affinity towards alkali and alkaline earth metal cations and ammonium ions. 19 20-22 Therefore, we have been interested in studying the effect of alkyl chain length in the crystal packing of the resorcinarene bis-crowns and their metal complexes, where it can (a) influence the twisting of the resorcinarene framework and (b) induce a layer or bilayer 75 packing when the hydrophobic effect of the alkyl chains becomes strong enough. The alkyl chain length also affects the amphiphilic properties and self-assembly in water, which was studied by preparing SLNs out of series of resorcinarene bis-crowns with short, medium and long alkyl chains.…”

Synthesis, Structure, and Exctraction Ability of Tetrasubstituted Thiacalix[4]Arenes with Crown Ether Fragments on the Lower Rim

“…These compounds have the receptor ability towards alkali and alkaline-earth metal cations and their binding selectivity mainly depends on the number of oxygen atoms in polyethylene glycol chain and calixarene stereoisomeric form. [1] Among them very selective receptor molecules were discovered. For example, calix [4]crown-6-ether in 1,3-alternate conformation demonstrated high Cs + /Na + selectivity (more than 30000).…”