Synthesis and Extraction Behaviour of Calix[4]arenes Partially Substituted at the Wide Rim by Carbamoylmethylphosphine Oxide (CMPO) Functions

Abstract

Tetraethers of calix[4]arenes fixed in the cone conformation and substituted at their wide rim by one to three CMPO residues and hydrogen atoms or t-butyl moieties in the remaining position(s) were synthesized. Liquid/liquid extraction studies of selected lanthanides and actinides were undertaken with these calix[4]arenes, including also a linear trimer, in order to obtain a better understanding for the extraction properties of the corresponding calix[4]arene substituted by four CMPO functions. The structure of the 1,3-di-CMPO derivative was confirmed by single crystal X-ray analysis.