Polynuclear complexes with d

10

metals

which often possess unique structures and properties

have drawn a lot of attention. For the preparation of tetranuclear zinc carboxylate

four methods have been used: (a) by the reaction between zinc oxide and the carboxylic acid in the appropriate proportion; (b) by the thermal decomposition of the neutral carboxylate Zn(RCO

2

)

2

; (c) by the reaction of zinc oxide with the neutral carboxylate and (d) by the hydrolysis of the neutral zinc carboxylate. In the present work

a tetranuclear zinc benzoate Zn

4

O(C

6

H

5

CO

2

)

6

was synthesized by the thermal decomposition of zinc benzoate Zn(C

6

H

5

CO

2

)

2

in an inert atmosphere. Its electronic absorption

infrared

excitation and emission spectra were investigated. The nature of luminescence and the relationship between structure and luminescent property were discussed. Structure refinement showed that Zn

4

O(C

6

H

5

CO

2

)

6

has a cubic structure

space group

Ia

-3

d

with great crystal cell:

a

=41.0063(18)Å

V

=68953(5)Å

3

Z

=48. In the crystal all benzoates coordinate with zinc atoms in a bidentate bridging mode

four zinc atoms form a regular tetrahedron. Each Zn

4

O(C

6

H

5

CO

2

)

6

molecule is in an octahedron geometry and every four adjacent molecules constitute a slightly distorted tetrahedron. The complex Zn

4

O(C

6

H

5

CO

2

)

6

possesses an infinitely extended three-dimensional supramolecular structure. It emits a green luminescence under the excitation of UV/blue light in solution or in the solid state. Its excitation and emission bands at 290～330 and 370nm are attributed to the ligand-centered transition. The excitation bands at about 460nm and the emission band at about 530nm are assigned to the LMCT (ligand to metal charge transfer) transition of

p

π

*

(L

O

2-

)-4sσ(Zn

2+

). The luminescent property has relation with its particular structure. In the nature of its excitation and emission spectra

a leading role is played by the arrangement of Zn

4

O tetrahedron around the central oxygen atom because of the absence of similar bands for the simple mononuclear complex Zn(C

6

H

5

CO

2

)

2

. Furthermore

in addition to the Zn

4

O unit

the OZn

4

O

12

one is needed to explain the nature of experimental bands. The green emission of complex Zn

4

O(C

6

H

5

CO

2

)

6

makes it a possible candidate for luminescent material.