Nicole Simon

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)Ph2 as well as some linear model compounds have been synthesized for the first time. Their ability to extract europium, thorium, neptunium, plutonium and americium from 1 mol dm–3 aqueous HNO3 into methylene chloride or o-nitrophenyl hexyl ether was studied under various conditions. All the new oligomeric ligands, but especially the calixarene derivatives, are tremendously strong extractants compared with the commonly used CMPO [(N,N-diisobutylcarbamoylmethyl)octylphenylphosphine oxide]. Also in transport studies through supported liquid membranes their efficiency is higher than that of CMPO which shows lower transport rates even at a 10-fold concentration.

A solution for cesium removal from high-salinity acidic or alkaline liquid waste: The crown calix[4]arenes

ABSTRACT The scientific literature abounds with articles on the extraction of cesium from liquid waste. From the 1940s, several classes of inorganic exchangers were used for cesium removal, such as zeolites, hexacyanoferrates, zirconium phosphate, ammonium phosphomolybdate, and, more recently, crystalline silicotitanate. Later, organic compounds like formophenolic resins, tetraphenylboron, or extractants such as dicarbollides or crown ethers were proposed. Generally, these compounds were only able to efficiently remove cesium under restrictive conditions (alkaline medium, low salinity, etc.) The performances of most of these compounds strongly decreased as the acidity (or salinity) of the liquid waste increased. Artifices had to be implemented to improve the performances of extractants. A restricted number of inorganic exchangers allowed the cesium removal, but often they could not be eluted or needed prohibitive volumes of saline eluent, leading to large volumes of secondary waste. Calix[4]arenes monocro...

EXTRACTION OF TRIVALENT LANTHANIDES AND ACTINIDES BY “CMPO-LIKE” CALIXARENES

ABSTRACT Extractive properties of calix[4]arenes bearing carhamoylmethylphosphine oxide moieties on their upper rim toward trivalent lanthanide and actinide cations were investigated. The study revealed that these molecules selectively extract light lanthanides and actinides from heavy lanthanides. All parameters present in the extraction system were varied to determine the origin of the selectivity. It was found that this selectivity requires a calix[4]arene platform and acetamidophosphine oxide groups containing phenyl substituents on the four phosphorus atoms.

‘CMPO-substituted’ calix[4]arenes, extractants with selectivity among trivalent lanthanides and between trivalent actinides and lanthanides

Calix[4]arenes substituted by acetamidophosphine oxide groups at their wider (upper) rim not only exhibit excellent extraction efficiency towards trivalent cations but also show pronounced selectivity for the light lanthanides and actinides in their extraction from highly saline or acidic media.

Calix[n]arene phosphine oxides. A new series of cation receptors for extraction of europium, thorium, plutonium and americium in nuclear waste treatment

A novel class of calixarene derivatives with phosphine oxide residues [Calix-(OCH2CH2POPh2)n] attached to the lower rim showing high efficiency in extraction of EuIII, ThIV, PuIV, and AmIV from simulated nuclear waste is reported.