Extraction compounds bearing CMPO

Selective Extraction of Actinides by Compounds Bearing CMPO Moieties... 

Since in the case of p-H calixarenes, a precipitate occurred at the water/organic interphase, extraction tests were carried at a concentration of 10" M for these compounds. The presence of tert-butyl or benzyloxy at the wide rim helps to solubilize the complexes. The distribution ratios are compared to wide-rim CPw3 and narrow-rim CPn3 (Table 4.34).179 For all CMPO-calix[6,8]arenes, distribution ratios of the two cations studied (Eu and Am) increase with increasing HN03 concentration, in agreement with what is observed with tetramers bearing CMPO residues... 

The wide-rim CMPO calix[4]arenes are the most efficient compounds for the extraction of trivalent actinides and lanthanides. They are also the compounds that display the highest selectivity along the lanthanide series, provided that phosphorus atoms are linked to phenyl groups. They also display a higher selectivity than the calixarene-bearing diphosphine oxide, where the phosphorus atom is linked to phenyl units CPo21.176- ... 

GRAPH 19.3 Comparison of the extraction properties (dependence of log on logarithm of nitric acid concentration) of low-rim calix[4]arenes bearing two ions and two CMPO groups in opposite positions of the platform. The compounds differ in length of the alkyl spacer (for Via = CjlT, VIb = C3Hg, Vic = C Hg, VId = CjH,o, Vie = CgH,2, Vlf = CjH, ) between the platform and CMPO function. Extractants are at very low concentrations 1 x 10 M in HMK/TPH (1 1). (T, the log value were determined as higher than 2.)... 

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