Blue electroluminescent emitter is essential for the development of a full-color display.However

blue emitting organic materials are rare compared to those of green.Lithium complex with 8-hydroxyquinoline with high yield and purity

which is a blue emitter

was synthesized by liquid-phase reaction and characterized by FTIR spectra

UV absorption spectra

XRD spectra

fluorescence spectra and its structure of energy band was studied by UV absorption spectra

cyclic voltammetry and fluorescence spectra.Results show that pH value and solvent have high influence on yield of Liq.From IR spectra of Liq

the broad characteristic peak at 3180cm

-1

corresponding to OH

-

stretching vibration peak(ν

OH

)and OH

-

bending vibration peak at 1223cm

-1

disappear in complex

the new peak appear at 483cm

-1

520cm

-1

which correspond to Li-Obond

which is ion bond.Liq is a thermally stable material

whose melting point is 365℃

which can form easily high quality amorphous film at glass substrates cleaned by vacuum evaporation.The powder of Liq is crystallographic

having two intense diffraction peak at 18.8°

21.7° in XRD spectra

whereas its film is amorphous.In the absorption spectra of Liq film

there are two absorption peak at 259nm

which is strong

and at 363nm

which is weak.The long wave absorption peak

which has contribution to fluorescence

was attributed to charge transfer transition from phenoxide ring with oxide to pyridyl ring with nitrogen.The strength of metal-nitrogen bond affects the position of this peak

the weaker metal-nitrogen bond

the shorter absorption wavelength.The LUMO energy

HOMO energy and optical gap of Liq is 2.90

5.91

3.01eV

respectively.Liq film can emit intense blue fluorescence with peak wavelength at 452nm and a full width at half-maximum of 69.4nm under UV excitation at 363nm.The Stokes shift of Liq film is about 5424cm

-1

because of electron-phonon interaction and the trapping state in band gap.