Many organic complexes of rare earth(Sm

Eu

Tb

Dy) have a fine luminescent properties. Because the homochromatism theirs fluorescence is good

the intensity of luminescent and their interior quantum efficiency are higher

that is benefit to the panchromatic display. In recent year it caused denseness interest in high-tech industry and the application foreground is very vast. For looking for the good photoluminescence and electroluminescence materials

in our work three ternary complexes of Tb were synthesized with o

m

p-methoxybenzoic acid (o-MOBA

m-MOBA

p-MOBA) as the first ligand and 1

10-phenanthroline(phen) as the second ligand.The content of Tb

C

H and N were measured by using EDTA titration method and a Flash-EA model 1112 elemental analyzer. The constitution of the three complexes was confirmed respectively as follows:(Tb(o-MOBA)

3

phen·H

2

O

Tb(m-MOBA)

3

phen·H

2

O and Tb(p-MOBA)

3

phen.The IR spectra of free ligands and complexes were recorded by model 1730 Fourier transform infrared spectroscopy with KBr pellet in the range of 350

3

500 cm

-1

. The results show that two characteristic absorption peak(υ

C=O

δ

O—H

) of methoxybenzoic acid disappeared and the anti-symmetric and symmetric (stretching) vibration absorption peak of carboxyl(υ

as

υ

s

) appeared in the complexes. These reveals that (methoxybenzoate) took part in the coordination. The characteristic absorption peak of phen(υ

C=N

δ

C—H

) shifted to lower frequencies at different degree in the title complexes

which shows two nitrogen atoms in the phen also took part in the coordination.Excitation and luminescence spectra of the title complex were carried out and recorded by using a Hitachi F-4500 fluorescence spectrophotometer. Excitation spectra of the title complexes were obtained in a rang e of 200

4

50 nm. Fluorescence spectra was observed in a range of 400-700 nm. The fluorescence spectra data shows four characteristic emission peak centered at 489

545

582 and 621 nm

which originated from the (

5

D

4

→

7

F

J

(

J

=6-3) transition of Tb

3+

ion respectively. The intensity of the transition fluorescence centered at 545 nm is the highest. The intensity of the transition fluorescence of the three complexes at 489 and 545 nm decreases according to the order o

m

p-methoxybenzoic acid. In a conclusion

three complexes of the terbium

Tb(o-MOBA)

3

phen·H

2

O

Tb(m-MOBA)

3

phen·H

2

O and Tb(p-MOBA)

3

phen were synthesized in C

2

H

5

OH solution. They result in strong emission with green color

among them the luminescent intensity of Tb(o-MOBA)

3

phen·H

2

O is the highest.