Complexation of trivalent lanthanoid ions with 4-benzoyl-3-phenyl-5-isoxazolone and p-tert-butylcalix[4]arene fitted with phosphinoyl pendant arms in solution during synergistic solvent extraction and structural study of solid complexes by IR and NMR

Coordination chemistry of a para-tert-octylcalix[4]arene fitted with phosphinoyl pendant arms towards 4f-elements: Extraction, synergism, separation

“…The most shifted protons upon coordination are methyl group and o-Ph protons from one of the phenyl ring in HP ( Figure 6). There is no change in the symmetry of ligand S upon coordination and all resonances of S remain in the same form as for free S ligand, which indicates uniform interaction of all P=O with Eu 3+ ion, as already observed in our previous investigations (26,27,30). The 31 P { 1 H} NMR spectra of EuP 3 ·S complex at 298, 313 and 333 K consist of a single resonance, which supports the conclusion of uniform interaction of all P=O with Eu 3+ ion ( Figure 6).…”

“…It is well known that P=O groups show a high affinity for f-elements. Tetra-phosphinoylated para-tertbutylcalix [4]arene (25)(26)(27) and octa-phosphinoylated para-tert-octylcalix [8]arene (28) compounds have been demonstrated to be useful synergistic agents for the solvent extraction of lanthanoids in combination with chelating or neutral (4) ligands using molecular diluent (CHCl 3 ) and ionic liquid (29). It has been established that the physicochemical properties of lower rim phosphinoylated reagents mainly depend on the size, the number of functional groups and the compound conformation whereas this dependency is not so clear for upper rim phosphoruscontaining ligands.…”

Coordination Chemistry of Europium(III) Ion Towards Acylpyrazolone Ligands

“…of mononuclear β-dicarbonyl lanthanoid complexes are generally high, varying from 6 to 12, and depend on the ionic radii of ions (La 3+ , Gd 3+ and Lu 3+ : 103.2, 93.8 and 86.1 pm, respectively), the ligand, the reaction medium, diluent, and conditions, such as temperature or ligand to metal ratio, with 8 and 9 being rather common. [22][23][24] Another fact responsible for the large C.N. is the large ionic radius of the lanthanoid elements, (Eu 3+ : 94.7 pm).…”

“…However, the coordination sphere of the trivalent ion is unsaturated in this six-coordinate chelate complex, so the lanthanoid ion can expand its coordination sphere by adduct formation, depending on the preparation protocol, with water for example LnL3·(H2O)x, x = 2 or 3. 22,23 The two solid europium(III) complexes synthesized in the present work using HPPMBP and HPMMBP as chelating ligands are of type a) as described above, with a change from water to EtOH for completion of the coordination sphere, when passing from one ligand to another, Fig. 3.…”

“…Furthermore, depending on the IL nature, the Tf2N -transfer may be below the detection limits of the NMR technique. 29 Another way that is different from the classical slope analysis 11,14,22,23 to determine the stoichiometry of the extracted species and can give insight into the first coordination sphere, is EXAFS. Distinction between oxygen atoms arising from H2O or Tf2N -or the ligand could be made provided model compounds with known X-ray structure and EXAFS spectra.…”