CMPO-substituted calix[6]- and calix[8]arene extractants for the separation of An(3+)/Ln(3+) from radioactive waste

Three calix[6]arene derivatives (1a-c) and two calix[8]arene derivatives (2a,b), with six and eight CMPO residues, respectively, attached to the narrow/lower rim via ether links, were synthesised. Preliminary liquid-liquid extraction studies for Eu(III) and Ann(III) from aqueous nitric acid to o-nitrophenylhexyl ether reveal remarkable properties with respect to efficiency and selectivity, especially for the tertbutylcalix[6]arene derivative with a -(CH2)(3)-spacer