一种锌希夫碱配合物的表征及发光性能研究

Characterization and Photoluminescence Properties of an Azomethin-Zinc Complex

合成并通过真空升华提纯得到了一种高纯度的希夫碱有机金属配合物水杨醛缩邻苯二胺合锌。通过元素分析、红外光谱、热重-差热曲线、紫外-可见光吸收光谱、荧光发射光谱和光致发光光谱表征了其结构、热稳定性以及能带结构。实验结果表明:水杨醛缩邻苯二胺合锌的玻璃化温度(Tg)高达183℃,分解温度为449℃;水杨醛缩邻苯二胺合锌是一种多晶粉末状的发光材料,在紫外光的激发下,在四氢呋喃溶液体系中的荧光发射峰在508nm处,为蓝绿色荧光,色纯度高,荧光量子效率高,禁带宽度2.62eV;利用真空热蒸镀很容易制备高质量薄膜,其发射峰在562nm处,半高宽为48.5nm的黄绿光发射。利用水杨醛缩邻苯二胺合锌为发光层制备了黄光有机电致发光器件。

Abstract A Schiff base organic metal complex, Bis（salicylidene）-l, 2-phenylenediam-ine Zinc（ H ） with high purity, was synthe- sized and purified by vacuum sublimation. Its structure, thermal stability and energy band structure were investigated by element analysis, FTIR spectra, TG-DTA curve, UV-Vis absorption spectra, fluorescece emission spectra and PL spectra. Experimental results showed that the complex is a thermally stable, polycrystalline material, with glass temperature and decomposition tem- perature being 183 and 449 ~C, respectively. In its infrared spectrum, a high intensity band was at about 1 385 em-1. This band was typical of the conjugated C^N stretching vibration, which shifted to higher frequency in relation to the free ligand of salieylaldehyde with 1,2-phenylenediamine. The new bnd at 529 cm-1 was assigned to Zn---O stretching vibration. Its UV ab- sorption bands were at about 297 and 406 nm, and its tetrahydrofuran solution emitted intensive blue-green fluorescence at the peak wavelength of 508 nln. The absorption band at about 406 nm can be assigned to the intrinsic absorption of C=N . Its op- tical gap was about 2.62 eV, which was determined by the intrinsic absorption band edge of the complex in tetrahydrofuran solu- tion. Under UV excitation at 365 nm, the complex in film emitted yellow-green fluorescence with the maximum emission peak at 562 nm and a full-width at half-maximum of 48. 5 nm in PL spectra. Finally, yellow organic light-emitting devices using this complex as the emissive layer were fabricated and investigated.