The synthesis and NOE-based structural characterization is described of thiacalix[4]arene tricarboxylic acid (7), thiacalix[4]crown-5 and -6 monocarboxylic acids (2 and 5), and the bis(N-methylsulfonyl)thiacalix[4]crowns-5 and -6 (4a,b). The 226Ra2+ selectivity coefficients, log(K(Ra)ex/K(M)ex), of the new thiacalix[4]arene derivatives are compared directly with those of thiacalix[4]crown-5 and...

Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the larg...

A new templating motif for the formation of [2]pseudorotaxanes is described in which rigid, Y-shaped axles with an imidazolium core and aromatic substituents at the 2-, 4- and 5-positions interact with [24]crown-8 ether wheels ([24]crown-8 and dibenzo[24]crown-8). The Y-shape of the axle significantly enhances the association between axle and wheel when compared to simple imidazolium cations.

The reaction of 4-bromo-aniline, 18-crown-6, and perchloric acid in methanol yields the title compound, C(6)H(7)BrN(+)·ClO(4) (-)·C(12)H(24)O(6), in which the protonated -NH(3) (+) group forms three bifurcated N-H⋯O hydrogen bonds to the O atoms of the crown ether.

A supramolecular lithium cation assemblies of crown ether, [Li 12-crown-4](+), has been used to replace conventional tetraalkylammonium counterion in thiolate/disulfide (ET(-)/BET) mediated dye-sensitized solar cells (DSCs), which exhibit high stability and efficiency of 6.61% under 100 mW·cm(-2) simulated sunlight illumination.

The title compound, [Fe(C(10)H(20)O(5))(H(2)O)(2)][Fe(2)(C(4)N(2)S(2))(4)]·2C(10)H(20)O(5), consists of an [Fe(II)(15-crown-5)(H(2)O)(2)](2+) cation, sandwiched between and O-H⋯O hydrogen bonded by two additional 15-crown-5 ether mol-ecules and two independent [Fe(III)(mnt)(2)](-) anions, where 15-crown-5 ether denotes 1,4,7,10,13-penta-oxacyclo-penta-decane and mnt denotes cis-1,2-dicyano-1,2-...

In this study two solid supports, silica and florisil, were impregnated with crown ether (dibenzo-18-crown-6) and Fe(III) ions and their efficiency was compared in the adsorption process of As(V) from aqueous solutions. The solid supports were impregnated with crown ether due to their ability to build complexes with positives ions. Fe(III) was used because of As(V) affinity for it. The impregna...

Crown ether complexation solubilizes organic and inorganic salts in nonpolar media. Induction of crystallization from such solutions can result in crystallization of the free salt rather than the complex. This affords the opportunity to examine solvent effects on the crystallization of salts and other polar materials, leading to the modification of crystal shape and lattice. This approach, whic...