Difluorophosphate as ligand for the synthesis of luminescent lanthanide complexes

The thesis describes the synthesis, characterization and photoluminescent behaviour of Group 3 and lanthanide difluorophosphate complexes. Such an anion was poorly investigated as ligand for trivalent metal centres belonging to this family. The difluorophosphate anion was obtained as ammonium salt by reacting ammonium fluoride and P4O10. The synthesis of complexes having general formula [Ln(PO2F2)3] was carried out under mild conditions by reacting ammonium difluorophosphate with the proper metal chloride in ethanol. Addition of a bidentate N- or O-donor ligand (L) to the reaction mixture afforded the related [Ln(PO2F2)3L] derivatives. The proposed formulations were confirmed by heteronuclear NMR and IR spectroscopy and magnetic measurements. The coordinated difluorophosphate ligand resulted stable towards hydrolysis. Among the investigated metal centers, high quantum yields were measured for the Eu(III) complexes, that exhibited noticeable antenna-effect from the coordinated ligands. The high chemical stability and the good luminescent features prompted to investigate the preparation of doped polymeric materials. As an example, fibrous poly(methylmetacrilate) with embedded [Eu(PO2F2)3(phen)] (phen = 1,10-phenanthroline) was obtained through electrospinning techniques. Materials of this type are of potential interest for development of advanced lighting and optic devices.