Synthesis, Structures And Properties Of Series Thienyl8-Hydroxyquinoline Derivatives

8-Hydroxyquinoline metal complex is excellent electron-transporting material and light emitting material, With high fluorescence efficiency (about30%), easily purification, Good film-forming properties of the vacuum evaporation, high melting point (>300℃) and good stability, which is considered to be the material of best achieve commercialization of OLED. In recent years, it has been shown that a simple method to tune the emission wavelength and the efficiency of the devices is to modify the2-,5-or7-position of the8-Hydroxyquinoline rings. In this paper, A series of2-arylethenyl-8-hydroxyquinoline ligands with a thiopheneyl,5-chloro-2-thiopheneyl, and thianaphthenyl group and their corresponding Zn(II) complexes were synthesized and characterized by means of1H NMR, ESI-MS, FT-IR and elemental analysis. The aggregation behavior of Zinc salt and ligands in solution was investigated by several techniques, containing1H NMR, UV-vis and photo luminescence (PL). The crystal structure of (E)-2-[2-(3-thiophenyl)ethenyl]-8-methoxyquinoline and (E)-2-[2-(3-thiophenyl)ethenyl]-8-hydroxyquinoline were characterized by single-crstal X-ray diffaction. Optical, thermal properties of (E)-2-[2-(3-thiophenyl)ethenyl]-8-hydroxyquinoline zinc complexes were investigated. And electroluminescent devices using them as emission layers (EL), hole-transporting layers (HTL) or EL&HTL were fabricated and characterized. Comparative study showed that the complex electron transfer capability is better than the hole transport ability. The reason may be due to the introduction of a thienyl group, which is more conducive to improve the electron transporting ability. Consisted with the report that thiophene compounds possed the excellent electron transport capability.