Extraction equilibrium and thermodynamics of cesium with a new derivative of calix[4]biscrown

Abstract

A new supermolecular recognition agent named tetra-tert-butyl-calix[4]-bis[(4-methly-1,2-phenylene-crown-6] (TertButylCalixC) was synthesized. Batchwise experiments of extraction of Na(I), K(I), Rb(I), Cs(I), Sr(II), Ba(II), Ru(III) and Fe(III) from aqueous solution with TertButylCalixC/o-nitroanisole were carried out. Effects of HNO 3 concentration, contact time and temperature on the extraction behavior were examined. The equilibrium established within 30 min implied a fast extraction kinetics. The optimal operation temperature was 298 K. Stoichiometry of TertButylCalixC and Cs(I) by electrospray ionization mass spectrometry characterization revealed 1:1 molar ratio. It was observed that the extraction system of TertButylCalixC/o-nitroanisole was effective for selective removal of Cs(I), showing remarkable separation performance.

Extraction Equilibrium of Typical Alkali Metals with a Macrocyclic Calixbiscrown Derivative in Two-Phase System HNO3/o-Nitroanisole and HNO3/HCCl3

“…This showed that in TTCalixB6/HCCl 3 extraction, one Cs­(I) was recognized only by one TTCalixB6. This was in agreement with the investigations carried out previously . It might reflect much higher stability of 1:1 type of the complex of Cs­(I) with TTCalixB6 than that of 1:2 type of the complex.…”

“…This was in agreement with the investigations carried out previously. 42 It might reflect much higher stability of 1:1 type of the complex of Cs(I) with TTCalixB6 than that of 1:2 type of the complex. On the other hand, a peak at m/z = 1239.7 was ascribed to TTCalixB6• HNO 3 , a 1:1 type of the associated species formed by one TTCalixB6 and one HNO 3 , implying the protonation of TTCalixB6 with HNO 3 .…”