The coordination compounds between rare earth nitrates and bis- Schiff bases derived from o-vanillin (2-hydroxy-3-methoxy-benzadehyde) and ethylenediamine, benzidine, o-phenylenediamine, m- phenylenediamine were synthesized in non-aqueous system. The Schiff bases are indicated as L^1, L^2, L^3, L^4 respectively. The compositions of the coordination compounds have been given by elementary analysis to be LnL(NO~3)~3 (L=L^1, Ln=La, Ce, Eu; L=L^2, Ln=La, Tb; L=L^3, Ln=La, Eu; L=L^4, Ln=La). The coordination modes of the bonding in these compounds were given on the basis of infrared spectra, molar conductance, X-ray powder diffraction analysis, X-ray photoelectron spectra studies. Their possible structures were proposed. Two nitrogen atoms and two oxygens in a ligand, four oxygen in two nitrate groups are bound to a rare earth ion. The lanthanide ions in the coordination compounds exhibit eight coordination numbers. The thermal analytical results indicate that the coordination compounds are stable up to 230℃. The thermal stability of the coordination compounds for the same ligands increases with decrease of lanthanide ionic radius. The excitation and fluorescent spectra of Eu(III) coordination compounds were also measured at 77K. The characteristic emission peak of Eu^3^+ was observed.

Key words: SYNTHESIS, BONDED, COMPLEX COMPOUNDS, SCHIFF BASE, DIAMINE, VANILLIN, RARE EARTH, BENZENEDIAMINE P, ETHANEDIAMINE, INFRARED SPECTROPHOTOMETRY