Synthesis, characterisation and extraction behaviour of calix[4]arene-based phosponic acids
| Authors | |
|---|---|
| Year of publication | 2002 |
| Type | Article in Periodical |
| Magazine / Source | Journal of the chemical society. Perkin transactions II, Physical organic chemistry |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.rsc.org/CFmuscat/intermediate_abstract.cfm?FURL=/ej/P2/2002/b105489a.PDF |
| Field | Analytic chemistry |
| Keywords | synthesis; extraction agent; calix[4]arene |
| Description | Three new bis(phosponic) acids were prepared by derivatization of p-tert-butylcalix[4]arene on the lower rim by -(CH2)x-PO3H2 groups and were fully characterized by NMR spectroscopy; some of them were further investigated by X-ray analysis. The compounds obtained were tested as extractants for La3+, Eu3+, Yb3+ and Th4+ in 0.1 - 1 M HNO3. Structural details of the complex HLn(H2L1)2 where Ln = Y, La, Eu were elucidated by NMR techniques in solution. The extraction efficiencies decrease with increasing length of the CH2 spacer; the dependence is not monotonic, and an extraordinary selectivity was observed for Yb. The extraction efficiency of Ln3+ for all of the ligands studied increased significantly with decreasing ionic radius. |
| Related projects: |