In order to study regularity of fluorescence of complexes about rare earth with different benzoic acid

we have prepared much of BA-compiexes

RC

6

H

4

COOH(R=o-NH

2

H

p-NH

2

o-OH

m-Cl

o-COOH

m-COOH

p-COOH

p-OH

m-NO

2

3

5-Dinitro

p-Br

o-I

2-OH-5-SO

3

H.They can be synthesized complexes with Sm

3+

Eu

3+

Tb

3+

Gd

3+

.Under UV-excitation the complexes with Eu

3+

Tb

3+

have higher emitting intensity than complexes with Sm

3+

Gd

3+

.There are some science bases about study a new luminophor.Spectra analyses of the complexes of europium with benzoic acid and its derivatives are discussed.The binary complexes of europium with benzoic acid and its derivatives benzene carbonic acid

phthalic acid

isophthahc acid

salicylic acid

o-aminobenzoic acid sulfosalicylic acid have been synthesized.They were characterized by elemental analysis

UV-Vis

IR

H NMR

fluorescence spectra and molar conductance.The UV spectra showed that the complexes' ultraviolet absorption were from the ligands(220-350 nm)

so that it could transfer energy to rare earth.The measurement results of the emission spectra of the complexes indicated as follows the emission of Eu(BA)

3

Eu(m-Phth)

3

·3H

2

O and Eu(o-Phth)

3

·3H

2

O consisted of three peaks at 582

596

and 618 nm which were caused from

5

D

0

→

7

F

J

(

J

=0

1

2)transition of Eu

3+

respectively.Among these peaks the emission from

5

D

0

→

7

F

2

is the shrongest.But the emission of Eu o-aminobenzoic acid consisted(of three)peaks at 399

452

547 nm

and that of sulfosalicylic acid-Eu only one peak at 407 nm

which(were caused)from ligands.Fluorescence spectra show that there aren't red-characteristic emission of Eu in Eu(o-Amino)

3

and Eu(Ssal)

3

.