ZHAO Yong-liang, ZHAO Feng-ying. Strengthen Effects of La<sup>3+</sup> and Tb<sup>3+</sup> on Luminescence of Eu<sup>3+</sup> in the Dilnuclear Complexes of Rare Earth with Phthalate and 2,2&rsquo;-Dipyridyl[J]. Chinese Journal of Luminescence, 2000,21(2): 150-155
ZHAO Yong-liang, ZHAO Feng-ying. Strengthen Effects of La<sup>3+</sup> and Tb<sup>3+</sup> on Luminescence of Eu<sup>3+</sup> in the Dilnuclear Complexes of Rare Earth with Phthalate and 2,2&rsquo;-Dipyridyl[J]. Chinese Journal of Luminescence, 2000,21(2): 150-155DOI:
Two series of dinuclear complexes of phthalate and 2
2'-dipyridyl with different molar ratio of Eu
3+
to Tb
3+
and Eu
3+
to La
3+
have been synthesized
respectively
Their IR absorption spectra
fluorescence spectra and TG-DTA curves have been studied.The synthesis of the complexes(Eu
x
Tb1-x)
2
L
3
L'(L=phthalate group
L'=2
2-dipyridyl)was performed through the reaction of the two ligands L' and L with the mixture of EuCl
3
and TbCl
3
in solution
and by the reaction of both ligands with EuCl
3
and LaCl
3
the complex of (Eu
y
La1-y)2L
3
L' was prepared.The luminescence spectra were taken on a F-3010 fluorescence spectrophotometer at room tempreture.The IR spectra were recorded on a Mattson Alpha Centauri FT-IR spectrophotometer with KBr pellet.The thermal analysis data were recorded on a Shimadau DT-40 thermal analysis instrument.The IR absorption spectra for all the complexes are similar.The spectra are obviously different with those of phthalate(KHL) and 2
2-dipyridyl. When the complexes were formed
the absorption peaks of COOH(1677cm
-1
)and C-OH(1287cm
-1
)disappeared.The anti-symmetric stretching vibrations of carboxylate group(as) shifted to lower frequencies
whereas the symmetric stretching vibrations(s)shifted to higher frequencies.These facts showed that phthalate was coordinated to the rare-earth ions.By comparison
there are two strong absorption peaks(1452.3cm
-1
and 1578.0cm
-1
)in 2
2'-dipyridly
whereas they shifted to about 1523cm
-1
and 1 616cm
-1
in the complexes. It indicates that the chemical bonds have been formed between rare earth ions and nitrogen atoms of 2