| 초록 |
A series of 8 novel cyclometalated iridium(III) compounds with phenylimidazole derivatives, Ir(tpim)3, Ir(tpdfim)3, Ir(tpfim)3, Ir(tpcim)3, Ir(itpim)3, Ir(itpdfim)3, Ir(itpfim)3, Ir(itpcim)3 were synthesized and their photophysical, electrochemical properties were reported. The optoelectronic characterization showed a dramatic shift in the emission of the complexes when an electron-withdrawing group was introduced to the ligand. The introduction of electron-withdrawing substituents at 2, 4-position or 4-position of the fluorophenylimidazole ligand emitted blue phosphorescence with λmax = 455 nm – 480 nm at room temperature. But 4-position of the cyanophenylimidazole ligand showed different behavior in the same condition, a very large bathochromic shift (λmax = 525 nm – 560 nm) was observed in compounds. DFT calculations accurately modelled the observed photophysical and electrochemical behavior of the complexes and pointed to an emission from a mixed charge transfer state. |
