Sensitization and intra-molecular energy transfer of Eu³⁺ by Tb³⁺ in Eu-Tb binuclear complexes/PMMA

Abstract

A series of Eu_0.5Tb_0.5(TTA)₃Phen/PMMA (TTA=thenoyltrifluoroacetone, Phen=phenanthroline) and Eu_0.5Tb_0.5(TTA)₃Dipy/PMMA (Dipy=2,2′-dipyridyl) were prepared by in-situ polymerization. The structures of the composites were characterized by IR spectra and electron spectrum. Photoluminescence properties were investigated by UV-Vis spectra and fluorescence spectra. Meanwhile, the energy transfer models were set up. The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. Eu_0.5Tb_0.5(TTA)₃Phen/PMMA and Eu_0.5Tb_0.5(TTA)₃Dipy/PMMA emitted mostly characteristic fluorescence of europium ion and intense red fluorescence with peak wavelength at 611.8 nm and bandwidth of 10.4 nm under UV excitation at 365 nm. Fluorescence intensity of Eu_0.5Tb_0.5(TTA)₃Phen/PMMA was found to be influenced with the content of MMA. The fluorescence emission of europium ions was greatly sensitized by terbium ions and the enhancement of red emission was most likely due to the energy transfer enhancement from Tb³⁺ to Eu³⁺.

Keywords

sensitization / energy transfer / rare-earth polymer / in-situ polymerization

References

[1] Hasegawa M., Ishii A., Kishi S. Picosecond Time-Resolved Luminescence of Pr(III) Complexes: Intramolecular Excitation Energy Transfer from Ligand to Pr(III)[J]. Photobiol. A, 2006, 178(3): 220-224.

[2] Song H., Wang J. Dependence of Photoluminescent Properties of CubicY₂O₃:Tb³⁺ Nanocrystals on Particle Size Temperature [J]. J. Lumin., 2006, 118(2): 220-226.

[3] Laitala V., Ylikoski A., Raussi H.M., . Time-Resolved Detection Probe for Homogeneous Nucleic Acid Analyses in One-Step Format[J]. Anal. Biochem., 2007, 361(1): 126-131.

[4] Zhao D., Hong Z., Liang C., . Enhanced Electroluminescence of Europium(III) Complex by Terbium(III) Substitution in Organic Light Emitting Diodes[J]. J. Thin Solid Films, 2000, 363(2): 208-210.

[5] Zhao D., Li W., Hong Z., . White Light Emitting Organic Electroluminescent Devices Using Lanthanide Dinuclear Complexes[J]. J. Lumin., 1999, 82(2): 105-109.

[6] Yang C. Y., Srdanov V., Robinson M. R., . Orienting Eu(dnm)₃phen by Tensile Drawing in Polyethylene: Polarized Eu³⁺ Emission[J]. Adv. Mater., 2002, 14(14): 980-983.

[7] Wong W. H., Chan K. S., Pun E. Y. B. Ultraviolet Direct Printing of Rare-Earth-Doped Polymer Waveguide Amplifiers [J]. Appl. Phys. Lett., 2005, 87(1): 011 103-011 105.

[8] Han Y., Lin J. Luminescence and Energy Transfer of Organically Modified Silica Xerogels (OMSX) Doped and Undoped with Eu³⁺ and Tb³⁺[J]. J. Solid State Chem., 2003, 171(2): 396-400.

[9] Roman P., Oleg P., Vlad L., . Luminescent Properties of PP and LDPE Films and Rods Doped with the Eu(III)-La(III) Complex[J]. Polym. Adv. Technol., 2006, 17(1): 20-25.

[10] Chen Z. Q., Guo D. C., Xia L. S., . Interaction of Fluorescence Property of Complexes of Rare Earth (Eu-Tb)[J]. Chin. J. Appl. Chem., 2007, 24(10): 1 157-1 161.

[11] Liu H. G., Feng X. S., Jiang K., . Influences of Compositions and Ligands on Photoluminescent Properties of Eu(III) Ions in Composite Europium Complex/PMMA Systems[J]. J. Lumin., 2007, 127(2): 307-315.

[12] Fosberg J. H. Complexes of Lanthanide (III) Ions with Nitrogen Donor Ligands[J]. Coord. Chem. Rev., 1973, 10: 195-200.

[13] Sato S., Wada M. Relations between Intramolecular Energy Transfer Efficiencies and Triplet State Energies in Rare Earth β-Diketone Chelates[J]. Bull. Chem. Soc. Japan, 1970, 43(7): 1 955-1 958.

[14] Dexter D. L. A Theory of Sensitized Luminescence in Solids[J]. J. Chem. Phys., 1953, 21: 836-850.

[15] Chen L., Bao J., Gao C. Combinatorial Synthesis of Insoluble Oxide Library from Ultrafine/Nano Particle Suspension Using a Drop-on-Demand Inkjet Delivery System[J]. J. Comb. Chem. Soc., 2004, 6(5): 699-708.

[16] Jiu H. F., Ding J. J., Sun Y. Y. Fluorescence Enhancement of Europium Complex Co-Doped with Terbium Complex in a Poly(Methyl Methacrylate) Matrix[J]. J. Non-cryst.Solids., 2006, 352(3): 197-202.

[17] Luo Y., Qing Y., Wu S. Magnetic Field and Methylene Chain Length Effects on Photochemistry of Bichromophoric Chain Species Containing 7-Nitro-2-Fluorenyloxy and Anilino Chromophores[J]. J. Photochem. Photobiol. A-Chem., 2007, 191(3): 91-96.

[18] Lv Y., Zhang J., Wang L., . Enhanced Electroluminescence of Eu by Tb³⁺ in Complexes Tb_1−xEu_x(TTA)₃Dipy[J]. J. Lumin., 2008, 128(1): 117-122.