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...

The enthalpies of solution of the cyclic ethers 1,4-dioxane, 12-crown-4 and 18-crown-6 in mixtures of ethanol and water have been measured within the whole mole fraction range at T = 298.15 K. The enthalpy of solvation has been calculated. In pure ethanol and pure water, the solvation enthalpy of the investigated cyclic ethers depends linearity on the number of -CH2CH2- groups in the cyclic eth...

The reaction of 4-bromo-3-methyl-anilinium perchlorate and 18-crown-6 in methanol solution yielded the title compound, C(7)H(9)BrN(+)·ClO(4) (-)·C(12)H(24)O(6). The protonated 4-bromo-3-methyl-amine unit contains one -NH(3) (+) substituent, resulting in a 1:1 supra-molecular rotator-stator structure, (C(7)H(9)Br-NH(3) (+))(18-crown-6), through three bifurcated N-H⋯(O,O) hydrogen bonds between t...

The reaction of 4-fluoro-aniline hydro-chloride, 18-crown-6 and ferric chloride in methano-lic solution yields the title compound, (C(6)H(7)FN)[FeCl(4)]·C(12)H(24)O(6), which has an unusual supramolecular structure. N-H⋯O hydrogen-bonding inter-actions between the NH(3) (+) substituents of the 4-fluoro-anilinium cations and the O atoms of the crown ether mol-ecules result in a rotator-stator-li...

In the title compound, C(7)H(10)N(+)·BF(4) (-)·C(12)H(24)O(6), the proton-ated 4-methyl-anilinium cation inter-acts with 18-crown-6 forming a rotator-stator structure, (C(6)H(4)CH(3)NH(3) (+))(18-crown-6), through three bifurcated N-H⋯(O,O) hydrogen bonds between the ammonium groups of the cations (-NH(3)) and the O atoms of the crown ether mol-ecule. The BF(4) (-) anions, the methyl group and ...

A novel [2]pseudorotaxane was successfully constructed by the complexation of dibenzo[24]-crown-8 (DB24C8) derivative bearing terpyridine moiety (1) with lanthanide ion (Tb(3+)) and fullerene-containing ammonium salt (2), exhibiting the controlled photophysical behaviors as a reversible luminescent lanthanide switch in the presence of K(+) or 18-crown-6 (18C6).

A 1,2-bis(pyridinium)ethane type axle containing a terpyridine chelate group, when combined with 24-membered crown ethers, forms [2]pseudorotaxanes, the stability of which can be controlled by coordination of metal ions with different geometries.

Sixteen lipophilic N-(X)sulfonyl carbamoyl lariat ethers with polyether ring sizes of 12-crown-4, 14-crown-4, 15-crown-5, and 18-crown-6 are utilized for competitive alkali metal cation extractions from aqueous solutions into chloroform. Variation of the electron-withdrawing properties of X in the series of methyl, phenyl, 4-nitrophenyl, and trifluoromethyl allows the influence of the acidity o...

A conductance study of the interaction between Cs+, Rb+, NH4+, K+, T1+ and Ag+ ions and18-crown-6 (18C6), benzo-18-crown-6 (B18C6), dicyclohexyl-18-crown-6 (DC18C6),dicyclohexyl-24-crown-8 (DC24C8), dibenzo-24-crown-8 (DB24C8) in different binarymixtures of acetonitrile (AN) with dimethylsulfoxide (DMSO) and dimethylformamide (DMF)at 25 °C has been carried out. Formation constants of the result...

In this article, a six-component self-sorting process that involves three types of crown ether macrocycle and three types of cation guest molecule was carefully and thoroughly investigated. The six components include three kinds of crown ether, namely bis(p-phenylene-34-crown-10) (BPP34C10), dibenzo-24-crown-8 (DB24C8) and benzo-21-crown-7 (B21C7), and their corresponding cation guest molecules...