Organic/polymeric electroluminescence (EL) has attracted much attention because of their potential applications in larger-area full-color flat-panel displays. Since the first high efficient organic light emitting diode (OLED)

which used the aromatic diamine as the hole transport layer and tris(8-hydroxyquinoline) aluminum (Alq

3

) as the electron transport/emission layer

was demonstrated by C. W. Tang in 1987

Alq

3

is commonly used as the electron transport and/or emitting layer in OLEDs for its high fluorescent efficiency

high crystallizing temperature and stable performance. Recently

in order to get higher efficient and stable devices

many efforts have been made on the synthesis of high luminescence efficient materials

such as ZnqCl

2

have been synthesized and also its light-emitting devices were prepared by P. Y. Liu etc. Methods of calculation quantum chemistry are effective tools for studying the mechanism of photostimulated luminescence materials. To our knowledge

up to the present

there has not been any theoretical report on the spectrum of ZnqCl

2

. In this paper

two derivatives of ZnqCl

2

(MqCl

2

M=Mg

Be) are designed

and the structures of MqCl

2

(M=Zn

Mg

Be) and Znq

2

were optimized in the ground states using ab initio HF and B3LYP methods. At the same time

the molecular structures of the first singlet excited state for ZnqCl

2

and its derivatives were optimized by CIS/6-31G(d). The absorption and excite spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31G(d) basis set. The calculated results of luminescence originate from the electronic transition from the hydroxphenol ring to the pyridine ring. The calculated results of emission spectrum for ZnqCl

2

and its derivatives have good agreement with the experimental data. All compounds (MqCl

2

M=Zn

Mg

Be) are excellent electrontransporting materials

the luminescence peak wavelength of them can be tuned little by different metals on the ligand 8-hydroxyquinolinateo anion.