CALIXARENES WITH DIPHENYLPHOSPHORYL ACETAMIDE FUNCTIONS AT THE UPPER RIM - A NEW CLASS OF HIGHLY EFFICIENT EXTRACTANTS FOR LANTHANIDES AND ACTINIDES

Various calix[4]arene tetraalkyl ethers and a calix[5]arene pentaalkyl ether substituted at the upper rim by the CMPO-like functional group -NH-C(O)-CH2-P(O)Ph(2) as well as some linear model compounds have bee n synthesized for the first time. Their ability to extract europium, t horium, neptunium, plutonium and americium from 1 mol dm(-3) aqueous H NO3 into methylene chloride or o-nitrophenyl hexyl ether was studied u nder various conditions, All the new oligomeric ligands, but especiall y the calixarene derivatives, are tremendously strong extractants comp ared with the commonly used CMPO N,N-diisobutylcarbamoylmethyl)octylph enylphosphine oxide]. Also in transport studies through supported liqu id membranes their efficiency is higher than that of CMPO which shows lower transport rates even at a 10-fold concentration.