Preparation and photoluminescent behaviors of bipyrimidine bridged dinuclear Eu (III) complexes and their PMMA polymer films

Four bipyrimidine bridged dinuclear Eu (III) complexes of fluorinated beta-diketones were synthesized and their photoluminescence behaviors in solution, solid powder state and poly(methylmethacrylate) (PMMA) films were investigated in detail. The results showed that Eu (III) complexes and their PMMA polymer films all exhibited strong characteristic emissions of the corresponding Eu (III) ion and highly monochromatic red emissions. Ac-cording to the emission spectra and luminescence decay curves, the Judd-Ofelt intensity parameters (Omega(2), Omega(4)), lifetime (tau) and quantum efficiency were calculated. Their high Omega(2) values suggested that the Eu (III) ion was in a highly polarizable ligand field in these complexes. Meanwhile the proposed energy transfer mechanisms of these complexes were also investigated and analyzed. In their PMMA polymer films, the luminescent lifetimes, quantum efficiencies were increased significantly as compared to their precursor Eu (III) complexes. Especially, the PMMA@Eu-2(TMPD)6.Bpm polymer film displayed the longest lifetime (tau = 0.946 ms) and highest quantum efficiency (Phi(Ln) = 71.9%). These results suggested that photoluminescence behaviors of dinuclear Eu (III) complexes doped in PMMA polymer films had been improved remarkably.

Automated summary

Four bipyrimidine bridged dinuclear Eu (III) complexes of fluorinated beta-diketones were synthesized and investigated for their photoluminescence behaviors in solution, solid powder state and PMMA films. The results showed strong characteristic emissions and highly monochromatic red emissions in both the complexes and their PMMA films. The photoluminescence behaviors of the complexes were significantly improved in the PMMA films, with increased luminescent lifetimes and quantum efficiencies.