초록 |
To understand the relationship between the narrowing of an emission band and structural changes, we synthesised tetradentate Pt-complexes. Pt-1 has two directly connected carbazole (Cz) moieties, Pt-2 has two additional methyl groups to Pt-1, and Pt-3 has one Cz moiety. The absorption and emission spectrum of Pt-2 were identical to those of Pt-1. Pt-3’s emission was observed at a shorter wavelength compared to the others. We achieved phosphorescence with high colour purity by introducing a tetradentate ligand. All the Pt-complexes showed a vibronic structure in the emission spectra measured at 77 and 300 K. The 0-0 vibronic band of the Pt-complexes is quite intense compared to the 0-1 vibronic band, which may be due to less structural change of the fused tetradentate ligand in the excited state relative to the ground state. The spacing of the 0-0 and 1-0 vibronic bands are 1487 and 1323 cm-1, respectively. |