Designs, Synthesis And Performances Research Of Novel Organic Light-Emitting Materials Based On Poly-salen Ligands

Organic light-emitting display materials have many advantages such as simple device manufacture technology, low priming voltage, flexible display, etc; and have a wide prospect in screen display scopes which include mobile, television computer etc. OLED materials have drawn much attention all over the world.A series of novel Zn(II)/Pt(II) complexes and corresponding mixed Zn(II)-Pt(II) complexes based on poly-salen ligands were designed and synthesized successfully. The chemical structures of the complexes were characterized by 1H NMR, 13C NMR spectra and IR spectra, and the luminescence properties, thermal stability and electrochemical properties of the complexes were characterized by UV-Vis absorption spectra, fluorescence spectra, thermogravimetric analysis and cyclic voltammetry measurements. Meanwhile, we studied the relationship between the properties and structure of complexes. The experimental results indicate:1. The poly-salen ligands have characteristic absorption band at 200 ~ 305 nm and 310 ~ 371 nm. When coordinated with Zn(II) ion, featurable absorption of the C=N was shifted to 370 ~ 435 nm; the red-shift phenomenon was also observed to the C=N bond and a new absorption peak appeared between 450 ~ 595 nm in poly-salen-Pt(II) complexes.2. The main emission peak of poly-salen ligands appeared at 430 nm, while there was also a weak emission peak between 550 ~ 610 nm. To ploy-salen-Zn(II) and Pt(II) complexes, the emission peaks on the long wavelength shifted to 500 ~ 570 nm and 550 ~ 660 nm, respectively. On the other hand, the emission wavelength of mixed poly-salen-Zn(II)-Pt(II) complexes could be adjusted by changing the excitation wavelength as well as the ratio of Zn(II) and Pt(II).3. The fluorescence quantum efficiencies of poly-salen ligands and the corresponding Zn(II)/Pt(II) complexes were measured and calculated. The fluorescent quantum efficiencies of the complexes were around 0.89% ~1.69%.4. Cyclic voltammetry revealed that ELUMO and EHOMO values of the Poly-salen-Zn(II) complexes were -1.51 ~ -2.27eV and -4.38 ~ -4.67 eV, respectively. The thermogravitometric analysis showed that the decomposition temperature of the Zn(II) and Pt(II) complexes were around 400 ~ 450°C and 350 ~ 400°C, respectively.In summary, the Zn(II) and Pt(II) complexes based on poly-salen ligands have high decomposition temperature and appropriate energy band gap, which might provide a way towards developing new high-performance OLED materials.