苯甲酸-镝-钇配合物的发光

LUMINESCENCE OF Dy-Y-BENZOATE COMPLEXES

合成了苯甲酸-镝-钇固体配合物并研究了它们的光致发光性质.实验结果表明,当苯甲酸镝中部分Dy^(3+)离子被Y^(3+)离子取代时,可以便配合物中Dy^(3+)离子的发光增强.

Dysprosium-Yttrium-benzoate solid complexes, (Dy1-x Yx)L3, have been synthesized with homophase precipitation method in aqueous solution. Their luminescence properties and the influence of concentration of Y3+ ions added on luminescence intensity of the complexes were studied. According to the IR absorption spectra of (Dy1-xYx)L3 and the results investigated by Taylor to the structure of anhydrous rare earth ben-zoates, the supposed coordination structure for the complexes is as followThe emission spectra of EuL3, DyL3 and (Dy1-xYx)L3 show that Dy3+ ion in rare earth benzoate occupies the similar site of Eu3+ ion which is not a centre of symmetry in benzoate.Because the occurrence of concentration quenching with higher concentration of Dy3+ ions, the f→f transition for Dy3+ ion in pure DyL3 is very weak. It was found in experiments that if Y3+ ions as a reactent were added in synthetic process of DyL3, the luminescence intensity of Dy3+ ions could be substantialy enhanced and was obtained with satisfactory result when the substitution of 85 mole% Dy3+ for Y3+ ions. The energy transfer between benzoic group and Dy3+ ion through the excitation and emission spectra of NH4L and complexes the absorption spectra of DyL3, as well as the quenching of TTA to the Dy3+ ions emission were observed.The luminescence of physical mixture of DyL3 with YL3 in any propotion is weaker than the pure DyL3. Only the doped Y3+ ions in a way of common precipitation can raise the omission intensity of Dy3+ ions. From this fact, it may be supposed that (Dy1-xYx)L3 is a kind of solid solution, besides the dilution to Dy3+ ions, and the YL3 'should play a role of intermolecular transfer of energy in the complexes. The Y/B ratio of Dy3+ ions in aqueous complexes is greater than that in anhydrous complexes.The Y/B ratio of Dy3+ ions in anhydrous complexes is not changed with the change of the concentration of Dy3+ ions.