In recent years

there has been considerable interest in the study on the luminescence enhancement effects of the rare earth complexes.An effective approach to increase the luminescent efficiency is to modify the complexes with different kinds of counter ions

such as Cl

-

NO

-

3

ClO

-

4

.Another way is to mix certain anion rare earth ions

such as La

3+

Gd

3+

and Y

3+

could significantly enhance the luminescence intensities of the complexes of Eu

3+

Tb

3+

and Sm

3+

.In order to study the luminescence enhancement effects of anion ions

a series of europium complexes of 2-thiopheneglyoxylic acid(HL)

o-phenathroline(phen) and triphenyl phosphine oxide(TPPO) with different molar ratios of Eu

3+

to Y

3+

and Gd

3+

have been synthesized.The luminescence spectra were taken on WGY-10 fluorescence spectrophotometer.Enhancement of Eu

3+

fluorescence in Eu-L-phen complex system has been observed by addition of Y

3+

and reach maximum when the molar ratio of Eu

3+

:Y

3+

is 0.7:0.3.Then the(luminescence) intensity of the complexes decreases with a further increase of the Y

3+

content.Concluded from R=

I

t

/

I

p

(

I

t

=theoretical values of the fluorescence emission intensity

I

p

=practical values) is all above(1.0).When Y

3+

ions added to Eu-L-TPPO complex system

weak sensitization even extinguishment to some extent could be observed.In this system

R values of each complex approach 1.0.When a little amount of Gd

3+

ions added to Eu-L-TPPO complex system

it can extinguish the fluorescence intensity.R values are(below) 1.0 when molar ratio of Eu

3+

: Gd

3+

is 1:0

6

:4

only the R value for peaks at 699 nm is 1.3 when molar ratio of Eu

3+

:Gd

3+

is 6:4.But adding a large amount of Gd

3+

ions can sensitize obviously.This kind of luminescence enhancement due to the energy transfer process between ligands and lanthanum ions.The luminescence enhancement effects of counter ions(NO

-

3

Cl

-

ClO

-

4

) were also studied.In binary complexes

the fluorescence intensity of chloride system is the largest of all

and that of nitrate system the(largest) in ternary complexes.Luminescence properties of lanthanide ions could be great influenced by the(geometry) of their complexes

respectively.