Jean-Claude Bunzli - 5f-Element complexes with a p-tert-butylcalix[4]arene bearing phosphinoyl pendant arms: Separation from rare earths and structural studies

Version 1

      Publication Details (including relevant citation   information):

      Ramirez,F.D., Varbanov,S., Bunzli,J.C.G., Scopelliti,R.   Inorganica Chimica Acta 2011  378 (1) 163-168

      Abstract: Phosphinoylated calixarenes feature   high coordination ability toward f elements and a great   potentiality toward actinide/rare earth separation. Here, we   report three characteristic properties of a tetra-phosphinoylated   p-tert-butylcalix[4]arene, B(4)bL(4) functionalized with   phosphinoyl pendant arms: (i) its coordination ability toward   Th(IV) complexation in organic medium, (ii) its ability to   separate thorium from yttrium, lanthanum, and europium in three   different organic media, and (iii) the X-ray crystal structure of   the La complex. Thorium(IV) forms 1:1 and 1:2 (M:L) complexes   with B(4)bL(4): Th(NO3)(4)(B(4)bL(4))(n)center dot xH(2)O (n = 1,   x = 1, 1; n = 2, x = 4, 2). Spectroscopic data point to the inner   coordination sphere of 1 and 2 containing nitrate ions and water   molecules. Molecular modeling of 1 yielded an 8-coordinate   species and its coordination polyhedron can be described as a   distorted square antiprism while that for 2, a 9-coordinate   species, as a distorted tricapped trigonal prism. The extraction   study of tetravalent thorium and trivalent rare-earth (Y, La, Eu)   ions from acidic nitrate media by B(4)bL(4) in chloroform shows   thorium being much more extracted than the rare earths, with   selectivity close to 100%. The extraction behavior can be easily   modulated by changing the initial conditions (pH, nitrate   concentration). The X-ray structure of [LaB(4)bL(4)(H2O)(5)]   CH3CN center dot(ClO4)(3) points to the La-III ion lying on a C-4   axis and being 9-coordinated by the four O(P) atoms and five O   atoms from water molecules. It is located in the middle of the   void formed by the four O-CH2-PO(Me)(2) pendant arms. (C) 2011   Elsevier B.V. All rights reserved

      Address (URL): WOS:000296538000024