2, 6-双(2-苯并咪唑)吡啶-乙酸锌的合成和光谱性能

合成了一种新型的蓝光发射材料2,6-双(2-苯并咪唑)吡啶-乙酸锌,并利用元素分析、红外光谱、UV-Vis吸收谱、荧光激发光谱和荧光发射光谱研究了其结构、光学特性、能级结构和发光机理。结果表明,2,6-双(2-苯并咪唑)吡啶-乙酸锌是一种三齿配体的发光材料。在N,N-二甲基甲酰胺(DMF)溶液体系中测定了材料的紫外吸收光谱,2,6-双(2-苯并咪唑)吡啶的吸收峰波长主要为330,344nm;2,6-双(2-苯并咪唑)吡啶-乙酸锌的吸收峰波长主要为346,366nm。禁带宽度为3.01eV,在紫外光激发下,在DMF溶液体系中的荧光发射峰在458nm处,固态荧光发射峰在475nm,均为蓝色荧光,色纯度高,荧光量子效率高,其荧光发射主要来源于长波吸收带,最大波长吸收带对荧光发射贡献最大。有望通过合理的设计运用到有机电致发光器件中去。

Synthesis and Spectroscopic Properties of 2,6-bis (benzimidazol-2-yl) pyridine-zinc Acetate

In recent year, organic electroluminesence (EL) has attracted much attention because of its potential applications in large area full color flat panel displays. Organometallic complexes, which have five-or six-membered ring structures, with high stability, high melting point and high fluorescence quantum efficiency, are widely applied in organic EL devices. Organometallic complexes formed with imidazole, benzimidazole or pyridyl benzimidazole as small molecular ligand have attracted widespread attentions because of their high photoluminescence and electroluminesence officiency. In this paper, a new light emitting material 2,6-bis(benzimi-dazol-2-yl)pyridine-zinc acetate was synthesized. Its structure and optical properties were investigated by FT-IR spectra, UV-Vis absorption spectra, fluorescence excitation spectra and emitting fluorescence spectra. Its energy band and light emission mechanism were discussed. Results show that 2,6-bis(benzimidazol-2-yl)pyridine-zinc acetate is a tridentate ligand light emitting material. Its infrared spectra show relatively high intensity band at about 1 606 cm^-1. This band is typical of the benzimidazole ring conjugated C=N stretching vibration, which shifts to lower frequency related to the free ligand.The pyridine ring conjugated C=N stretching vibration at 1620 cm^-1, it also shifts to lower frequency related to the free ligand. Its UV absorption bands are at 346 nm and 366 nm, which can be assigned to nitrongen→zinc charge transfer.The complexe in N,N-dimethylformamide emitted intensive blue fluorescence with peak wavelength of 458 nm and its powder form also emitted intensive blue fluorescence with peak wavelength of 475 nm under UV irradiation.Its optical gap was estmated about 3.01 eV. Its fluorescence is chiefly attributed to the long wavelength excitation band. The complexe is expected to find applications in organic electroluminesence diodes through appropriate design.