Fluorescence enhancement of rare earth Tb(III) by Tm(III) in benzyl benzoylmethyl sulphoxide complexes.

A series of rare earth complexes [(Tb(x) Tm(y))L5 (ClO4)2](ClO4)·3H(2) O (x:y = 1.000:0.000, 0.999:0.001, 0.995:0.005, 0.990:0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200, 0.700:0.300; L = C(6) H5 CH2 SOCH2 COC6 H5) (Tb(III) luminescence ion; Tm(III) doped inert ion) were synthesized and characterized by elemental analysis, infrared spectra (IR) and (1) H-NMR. The photophysical properties of these complexes were studied in detail using ultraviolet absorption spectra, fluorescent spectra and lifetimes. The fluorescence spectra of complexes indicated that the fluorescence emission intensity was significantly enhanced by Tm(III). The complexes showed the best luminescence properties when the mole ratio Tb(III):Tm(III) was 0.990:0.010. The fluorescence intensity could be increased to 390%. Additionally, phosphorescence spectra and the luminescence mechanisms are discussed.

Syntheses and fluorescence properties of two novel lanthanide (III) perchlorate complexes with bis(benzylsulfinyl)methane.

A novel ligand with double sulfinyl groups, bis(benzylsulfinyl)methane, was synthesized by a new method and its two lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, (1)HNMR and UV spectra. The results indicated that the composition of these complexes was REL(2.5)(ClO(4))(3)·3H(2)O (RE = Tb (III), Dy (III), L = C(6)H(5)CH(2)SOCH(2)SOCH(2)C(6)H(5)). The FT-IR results revealed that the perchlorate group was bonded with the lanthanide ion by the oxygen atoms, and the coordination was bidentate. The fluorescent spectra illustrated that both the Tb (III) and Dy (III) complexes displayed characteristic fluorescence in solid state, especially for the Tb (III) complex, the peak of (5)D(4) → (7)F(5) of the Tb (III) ion in 544 nm was stronger than that of others. It indicated that the Tb (III) complex could emit purer green fluorescence. By analysis fluorescence and phosphorescence spectra, it was found that the ligand had the advantage to absorb energy and transfer it to the Tb (III) and Dy (III) ions. The phosphorescence spectra and fluorescence lifetimes of the complexes were also measured.

Fluorescence emission mechanism and fluorescence properties of ternary Tb(III) complex with diphenyl sulphoxide and bipyridine.

A novel ternary complex, TbL(5) L'(ClO(4))(3) · 3H(2)O, two binary complexes, TbL(7) (ClO(4))(3) · 3H(2)O and TbL'(3.5) (ClO(4))(3) · 4H(2)O has been synthesized (using diphenyl sulphoxide as the first ligand L, bipyridine as the second ligand L'). Their composition was analysed by element analysis, coordination titration, IR spectra and (1) H-NMR, and the fluorescence emission mechanism, fluorescence intensities and phosphorescence spectra were also investigated by comparison. It was shown that the ternary rare-earth complex showed stronger fluorescence intensities than the binary rare-earth complexes in such material. The strongest characteristic fluorescence emission intensity of the ternary system was 8.23 times, 3.58 times as strong as that of the binary systems TbL(7) (ClO(4))(3) · 3H(2)O and TbL'(3.5) (ClO(4))(3) · 4H(2)O, respectively. By fluorescence analysis it was found that both diphenyl sulphoxide and bipyridine could sensitize the fluorescence intensities of rare-earth ions. In particular, in the ternary rare-earth complex, introduction of bipyridine was of benefit to the fluorescence properties of Tb(III).

Synthesis and luminescence properties of two novel lanthanide (III) perchlorate complexes with bis(benzoylmethyl) sulfoxide and benzoic acid.

Two novel ternary rare earth complexes of Tb(III) and Dy(III) perchlorates with bis(benzoylmethyl) sulfoxide (L) and benzoic acid (L') had been synthesized and characterized by elemental analysis, coordination titration analysis, molar conductivity, IR, TG-DSC, (1)HNMR and UV spectra. The results indicated that the composition of these complexes was REL(5)L'(ClO(4))(2) x nH(2)O (RE = Tb(III), Dy(III); L = C(6)H(5)COCH(2)SOCH(2)COC(6)H(5), L' = C(6)H(5)COO; n = 6,8). The fluorescence spectra illustrated that the ternary rare earth complexes presented stronger fluorescence intensities, longer lifetimes and higher fluorescence quantum efficiencies than the binary rare earth complexes REL(5) x (ClO(4))(3) x 2 H(2)O. After the introduction of the second ligand benzoic acid group, the relative fluorescence emission intensities and fluorescence lifetimes of the ternary complexes REL(5)L'(ClO(4))(2) x nH(2)O (RE = Tb(III), Dy(III)) enhanced more obviously than the binary complexes. This indicated that the presence of both organic ligands bis(benzoylmethyl) sulfoxide and the second ligand benzoic acid could sensitize fluorescence intensities of rare earth ions, and the introduction of benzoic acid group was resulted in the enhancement of the fluorescence properties of the ternary rare earth complexes. The phosphorescence spectra were also discussed.

The studies of enhanced fluorescence in the two novel ternary rare-earth complex systems.

Two novel ternary rare-earth complexes SmL(5).L'.(ClO(4))(2).7H(2)O and EuL(5).L'.(ClO(4))(2).6H(2)O (the first ligand L = C(6)H(5)COCH(2)SOCH(2)COC(6)H(5), the second ligand L' = C(6)H(4)OHCOO(-)) were synthesized and characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, (1)HNMR and UV spectra. The detailed luminescence studies on the rare-earth complexes showed that the ternary rare-earth complexes presented stronger fluorescence intensities, longer lifetimes, and higher fluorescence quantum efficiencies than the binary rare-earth materials. After the introduction of the second ligand salicylic acid group, the relative emission intensities and fluorescence lifetimes of the ternary complexes LnL(5).L'.(ClO(4))(2).nH(2)O (Ln = Sm, Eu; n=7, 6) enhanced more obviously than the binary complexes LnL(5).(ClO(4))(3).2H(2)O. This indicated that the presence of both organic ligand bis(benzoylmethyl) sulfoxide and the second ligand salicylic acid could sensitize fluorescence intensities of rare-earth ions, and the introduction of salicylic acid group was a benefit for the fluorescence properties of the ternary rare-earth complexes. The fluorescence spectra, fluorescence lifetime and phosphorescence spectra were also discussed.

Synthesis and fluorescence properties of lanthanide (III) perchlorate complexes with naphthyl-naphthalinesulphonylpropyl sulfoxide.

A ligand with double sulfinyl groups, naphthyl-naphthalinesulphonylpropyl sulfoxide(dinaphthyl disulfoxide, L), was synthesized by a new method and its several lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DTA, (1)HNMR and UV spectra. The composition of these complexes, were RE(2)(ClO(4))(6).(L)(5).nH(2)O (RE = La, Nd, Eu, Tb, Yb, n = 2 approximately 6, L = C(10)H(7)SOC(3)H(6)SOC(10)H(7)). The fluorescent spectra illustrated that the Eu (III) complex had an excellent luminescence. It was supposed that the ligand was benefited for transferring the energy from ligand to the excitation state energy level ((5)D(0)) of Eu (III). The Tb (III) complex displayed weak luminescence, which attributed to low energy transferring efficiency between the average triplet state energy level of ligand and the excited state ((5)D(4)) of Tb (III). So the Eu (III) complex displayed a good antenna effect for luminescence. The phosphorescence spectra and the relationship between fluorescence lifetime and fluorescence intensity were also discussed.