Acta Phys. -Chim. Sin. ›› 1991, Vol. 7 ›› Issue (03): 362-365.doi: 10.3866/PKU.WHXB19910321

• Note • Previous Articles     Next Articles

Study on Rare Earth-Hedta-Serine Ternary System by Potentiometry and Fluorescence Spectroscopy

Gao Feng; Niu Chun-Ji; Ni Jia-Zuan   

  1. Changchun Institute of Applied Chemistry, Academia Sinica, Changchun 130022
  • Received:1990-02-28 Revised:1990-08-26 Published:1991-06-15
  • Contact: Niu Chun-Ji

Abstract: In this paper a rare earth-HEDTA-serine (Ser) ternary system has been studied by potentiometric titration at 25 ℃ with an ionic strength of 0.15 mol·L~(-1)(NaCl). The excitation and fluorescence spectra of TbCl_3, Tb-Ser,Tb-HEDTA and Tb-HEDTA-Ser have been determined at room temperature. The stability constants of these ternary complexes have been obtained. It has been found that Tb-HEDTA-Ser ternary system exhibit scharacteristic fluorescence spectrum of Tb~(3+) sensitized by two ligands. The results mean that the chemical bond tetween the central ion and the ligand in this ternary system is predominantly ionic in character, and the energy transfer from ligand to Tb~(3+) is performed by a kind of short-range electron exchange action.

Key words: Rare earth-HEDTA-Serine ternary, Potentiometric titration, Fluorescence