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).