The Synthesis, Structural Characterization And Photophysical Properties Of Several Bipyridine Ligands And Phenylpyridine Ligand Iridium Phosphorescent Molecular Materials

Phosphorescent iridium(?)complexes are widely used in organic light-emitting devices,light-emitting electrochemical cells,electrochemical sensors,because of their long phosphorescent lifetime,lower driving voltage,excellent thermal stability and durability,controllable wavelength.In this thesis,five new Iridium phosphorescence complexes were designed,synthezied and structurally characterized.And their photo-physical profiles were determined.The results show that the control in light-emission wavelengths can be realized by choosing proper substituent groups on bipyridine ligand.Phosphorescent iridium(?)complexes generally consist of the cyclometalation ligand,and diketone or bipyridine as the ancillary ligand.By introducing3,5-dimethylphenyl group into 2,2'-bipyridine,three cation phosphorescent iridium(?)complexes,as illustrated in the following figure,were synthesized.And two new2,4-difluorophenylpyridine iridium(?)complexes of diketone derivatives were also synthesized.The structures of all target complexes were confirmed by ~1H NMR,IR,MS and X-ray single crystal diffraction analysis.Both the fluorescence emission and UV-visible absorption spectrometry were employed to measure their photophysical properties.Figure 1.Chemical structures of the target complexesThe results show that three cation phosphorescent iridium(?)complexes reveal the maximum an maxmum emission band at 577,589 and 529 nm,respectively.Two new 2,4-difluorophenylpyridine iridium(?)complexes were found to emit the green lights.Figure 2.Chemical structures of the target complexes...