Calix[4]arenes with CMPO functions at the narrow rim. Synthesis and extraction properties
- 1 January 1999
- journal article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 4,p. 719-724
- https://doi.org/10.1039/a900210c
Abstract
The synthesis of three new derivatives of tert-butylcalix[4]arene bearing four carbamoylmethylphosphine oxide (CMPO) groups as ligating functions on the narrow rim is described. These are easily prepared in 65–80% yield via acylation of the corresponding fixed cone aminoalkoxy (C2 to C4) derivatives with p-nitrophenyl (diphenylphosphoryl)acetate. Extraction studies of selected lanthanides (La3+, Eu3+, Yb3+) and thorium (Th4+) from 1 M HNO3 to CH2Cl2 show a strong increase of the percentage extracted (%E) with increasing length of the spacer. Extraction of Am3+, La3+, Nd3+, Sm3+ and Eu3+ from (0.1–4) M HNO3 into o-nitrophenyl hexyl ether shows, in contrast to the wide rim CMPO derivative, no decrease of the distribution coefficient for higher concentrations of nitric acid.Keywords
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