CROWN ETHERS AND p-tert-BUTYLCALIX[4]ARENE MIXTURES AT THE CHLOROFORM / WATER INTERFACE.

The study presents the effect of adding p-tert-butylcalix[4]arene, benzo ether crowns and their equimolecular mixture in the organic phase on the interfacial tension for the chloroform water interface. It was found that addition of macrocyclic ligands to the organic phase has different effects on the interfacial tension. The higher the number of oxygen atoms in the ethereal ring of the benzo crown ethers, the higher the values of interfacial tension, while same modification of the ethereal ring produces an opposite effect in the case of amino benzo ethers, indicating different arrangements of molecules in the interface. The simultaneous presence of p-tert-butylcalix[4]arene and benzo crown ethers in the interface leads, in some situations, to significant changes in the interfacial tension values, a phenomenon explained by the modification of the macrocyclic ligands assembly in the interface. Also, composition of the aqueous phase influences the value of measured interfacial tension, type of the alkaline cation from the aqueous solution leading to different behavior of macrocyclic ligands in the interface. [ABSTRACT FROM AUTHOR]