In the title compound, 2C(15)H(17)NOS·C(12)H(24)O(6), the asymmetric unit consists of one N-oxide derivative and one-half of the 18-crown-6 ether, which lies on an inversion centre. In the crown ether, the O-C-C-O torsion angles indicate a gauche conformation of the ethyl-eneoxy units, while the C-O-C-C torsion angles indicate planarity of these segments. In the N-oxide unit, the dihedral angle...

Abstract Crown ethers containing an acridone or acridine unit are successfully applied opto- and electrochemical cation sensors. The heteroaromatic of these macrocycles can be in different forms during the applications, which have a strong influence on sensing behavior. Moreover, case acridono-macrocycles prototropic equilibrium takes place upon complexation, is effected by physicochemical char...

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.