The studies on the luminescence property of complexes of rare earth benzoate are attracting people's more interest increasingly.The luminescence of both complexes of Eu-Tb benzoate and complexes of Eu-La benzoate have been reported already;a high efficient Tb-Gd benzoate luminescence material was obtained by replacing a part of Tb

3+

with Gd

3+

;also fluorescence intensity can be enhanced by replacing a proportion of Eu

3+

with La

3+

.But interrelated report about Ca

2+

and Ba

2+

alkaline earth ions effecting fluorescence intensity of Eu

3+

was not seen yet.So group members decided to complete this work by choosing facile alkaline earth metal and it has significant value if corking effect was gotten.Aim at this

a series of complexes of benzoic acid with europium-calcium and europium-barium were synthesized by the reaction of europium chloride and calcium chloride(or barium chloride) with sodium benzoate in aqueous solution.Their composition is expressed with the general formula(Eu

1-x

Ca

x

)

L

3-x

and(Eu

1-x

Ba

x

)

L

3-x

where

L

=C

6

H

5

COO

-

x=0~1.0).Their infrared and fluorescence spectra were investigated.The characteristic asymmetric(ν

as

) vibrations of carboxyl group for Eu

L

3

(Eu

1-x

Ca

x

)

L

3-x

and(Eu

1-x

Ba

x

)

L

3-x

(x

<

0.7) shift to lower frequency and the other complexes shift to higher frequency;in comparison with symmetric(ν

s

) shift to lower frequency for EuL

3

and the other complexes shift to higher frequency.What is more

both the absorption bands(ν

as

and ν

s

) show splitting.From above analysis

we could draw a conclusion that the coordinating pattern of the carboxyl groups in the complexes is the form of chelating-bidentate and the tridentate chelating-bridging.The dependence of the relative fluorescence intensity of the complexes upon the content for Ca

2+

ion and Ba

2+

ion was discussed.The results showed that the emission intensity for Eu

3+

ions can be greatly enhanced if a part of Eu

3+

ion in europium benzoate was substituted by Ca

2+

ion or Ba

2+

ion.When x=0.1

the fluorescence intensity of the complexes is the highest.So it can be saying that not only the reserves abundant and inexpensive alkaline earth metallic ions were adulterated into complexes but higher fluorescence intensity than pure europium-benzoate complexes was achieved.These research results are very successful and will have wider application foreground.