Computational and experimental studies on the use of p-tert-butylcalix[4]crown-6 ether as an extractor for cesium

A new p-tert-butylcalix[4]crown-6 ether derivative was synthesized as a potential extractant for cesium and other alkali metal ions from water. The synthesized p-tert-butylcalix[4]crown-6 ether derivative was characterized via spectroscopic methods. The p-tert-butylcalix[4]crown-6 ether derivative was employed for the extraction of alkali metal ions as picrate and witnessed selective cesium ion extraction from the aqueous to organic phase with high efficiency. Both UV–Vis and atomic absorption spectrometry were used to assess the extraction efficiency. This material can be used in water purification systems for removing nuclear radioisotope cesium. The p-tert-butylcalix[4]crown-6 ether derivative was also analyzed using M06-2X/6-31G(d)/LANL2DZ methods. The computational method suggested the role of O–H⋯O and O–H⋯π interactions in the stability of different conformers of p-tert-butylcalix[4]crown-6 ether derivative. Moreover, it was witnessed through calculations that three conformers of p-tert-butylcalix[4]crown-6 ether derivative (cone, partial cone, and 1,3-alternate) can form a complex with cesium ion.