Abstract
This thesis contained two parts. The first one is dealing the platinum(II) complexes containing the benzyldiphenylphosphine, 2-phenylpyridine and 2-(2,4-difluorophenyl)pyridine as the chromophoric and ancillary ligand. Complex 2.1 2.8 were successfully synthesized and fully characterized. Complex 2.5, 2.6, and the corresponding intermediate [Pt(C^P)(μ-Cl)]2 were identified by single crystal X-ray diffraction. Beznyldiphenylphosphine underwent a reversible cyclometalation prior to the coordination of phenylpyridine, via cleavage of the metal-carbon bonding. This phenomenon was very interesting and different from those reported in the literature. On the other hand, we used deuterium labeling and 1H NMR spectroscopy to check the reaction mechanism. Complex 2.8 showed the best among this series of complex photophyscial properties with QY = 48.3%, emission λmax = 498 nm, and lifetime (τobs) = 4.19 μs. In part two, complex 2.9 2.12 bearing both the dianionic chelates, e.g. 5,5’-di(trifluoromethyl)-3,3’-bipyrazole and 5,5’-di(t-butyl)-3,3’-bipyrazole, and the neutral chelates, e.g. 2,2’-bipyrazine and 4,4’-bis(trifluoromethyl)-2,2’-bipyridine, were also successfully prepared. These complexes are essentially non-emissive in solution, but exhibited weak luminescence in the solid state with QY of 13.5% and 5.2% and peak max. λmax of 710 nm and 695 nm for 2.9 and 2.10, respectively. For complex 2.11 and 2.12, the non-emissive properties may be due to the loose packing in solid state or the lower lying metal-centered d-d state.