Effects of Bulky Substituent on the Phosphorescence Properties of Homoleptic Iridium(III) Complexes
발표자
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초록
내용
A new series of homoleptic cyclometalated iridium(III) complexes based on the phenylpyridine (ppy) ligand containing bulky substituents have been synthesized and characterized. Comparison of the results with those of the reference Ir(ppy)3 reveal that the emission color and photophysical properties of the other Ir complexes are influenced by the electron-donating groups (-CH3 and phenyl derivatives) attached to the ppy ligand. The emission spectrum of Ir(Me-ppy)3, having small electron-donating -CH3 group, is red-shifted; however, the emission quantum yield is low and the nonradiative decay constant is large. On the other hand, although bulky phenyl derivative-adducts (Ir(Ph-ppy)3, Ir(MePh-ppy)3, and Ir(diMePh-ppy)3) also exhibit red-shifted emission, but their kinetic and photophysical behaviors are more optimal than those of Ir(Me-ppy)3, whose behavior does not follow the energy gap law.