초록 |
In order to investigate the light-energy harvesting mechanism, a series of dendrimers with a heteroleptic iridium(III) complex core, [Ir(dmb)2(pic-Czn)] (Gn: n = 1, 2, and 3) was synthesized. The Ir-core [Ir(dmb)2(pic-OCH3), G0] shows a blue emission at ~500 nm, which is assigned to 3MLCT phosphorescence. This phosphorescence was enhanced with increasing generations due to the increase in the total absorbance of the Cz-dendron. The light-harvesting efficiencies determined by various methods were approximately 160 (G1), 220 (G2), and 330% (G3). The energy transfers efficiencies for G1–G3 from the peripheral Cz-dendron to the Ir-core complex were above 97%. The time-resolved TA band correlated with the core Ir-complex was observed at 500 nm, though it overlapped and interfered with the intense TA band of the Cz-dendrons. Therefore, we attempted a global analysis by singular value decomposition (SVD). |