Polychelates of Phenolic Ion-exchange Resin: Synthesis and Characterization

The polymeric ligand (resin) was prepared from 2-hydroxy-4-methoxybenzophenone with 1,2-propylene glycol in presence of polyphosphoric acid as a catalyst at 160ºC for 13 h. The poly[(2-hydroxy-4-methoxybenzophenone) 1,2- propylene glycol] (HMBP-1,2-PG) form 1:2 metal:ligand chelates with La(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III) and Dy(III). The polymeric ligand and its polychelates were characterized on the basis of elemental analyses, electronic spectra, magnetic susceptibilities, IR spectroscopy, NMR and thermogravimetric analyses. The molecular weight was determined using number average molecular weight (Mn) by vapour pressure osmometry method. All the polychelates are paramagnetic in nature except La(III) which is diamagnetic. Ion-exchange studies at different electrolyte concentrations, pH and rate have been carried out for lanthanides (III) metal ions.