Begum Tabakci

New diamino derivatives of p-tert-butylcalix[4]arene for oxyanion recognition: synthesis and complexation studies

We have prepared new diamino derivatives of p-tert-butylcalix[4]arene from the reduction of corresponding amide derivatives. The examination of their recognition abilities towards some selected oxyanions shows that the new calix[4]arene amines are mostly more effective receptors than their amide derivatives for dichromate anions and nitrite, and capable of extracting these anions in yields as high as 95%. However, neither the calix[4]arene amines nor their corresponding amides were capable of extracting phosphate or nitrate at pH 1.5.

Facilitated Transport of Cr(VI) Through a Bulk Liquid Membrane Containing p-tert-Butylcalix[4]arene Amine Derivative as a Carrier

The facilitated transport of Cr(VI) through a bulk liquid membrane (BLM) is investigated, using the by p-tert-butylcalix[4]arene amine derivative as mobile carrier. The transport efficiency of Cr(VI) by p-tert-butylcalix[4]arene amine derivative was investigated under various experimental conditions such as the influence of pH on the donor and the acceptor phase, effect of Cr(VI) and carrier concentration, the type of solvent, the stirring speed, and the temperature. The kinetic parameters (k 1, k 2, , t max , , ) were calculated for the interface reactions assuming two consecutive, irreversible first order reactions. The activation energy values are calculated as 5.94 and 12.51 kJ mol−1 for extraction and reextraction, respectively. The values of the calculated activation energy indicate that the process is diffusionally controlled by species.