The synthesis, photoluminescence and energy transfer mechanism of a reactive Eu(III)-complex intermediate of white light phosphor

Abstract

A reactive Eu(III)-complex intermediate of white light phosphor was synthesized using benzoylactone, 1,10-phenanthroline and undecylenic acid as ligands. The structure of the complex was characterized by elemental analysis and FT-IR spectra. The luminescent properties were investigated by fluorescence spectra and UV–vis absorption spectra. The results indicate that the complex emitted the characteristic peaks of the Eu(III) ion when being excited at 367 nm, revealing that the complex can be excited by 365 nm of ultraviolet. The energy of the highest occupied molecular orbital and the lowest unoccupied molecular orbital as well as the singlet state and triplet state energy level of the ligands were calculated with the Gaussian03 program package. Intramolecular energy transfer mechanism was studied and an energy transfer diagram was sketched to illuminate the energy transfer process. The Eu(III)-copolymer was synthesized by the free radical copolymerization of the Eu(III)-complex and methyl methacrylate. XRD analysis indicates that the Eu(III)-complex in the copolymer was dispersed much more uniformly into the polymer matrix than that in the doped polymer. The photoluminescent properties of the Eu(III)-polymer suggest that the Eu(III)-complex is a good candidate of red light moiety in white light phosphor.