Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea.
Chem Soc Rev. 2012 Nov 7;41(21):7061-84. doi: 10.1039/c2cs35171d. Epub 2012 Jul 16.
The development of cyclometalated Ir(III) complexes has enabled important breakthroughs in electroluminescence because such complexes permit the efficient population of triplet excited states that give rise to luminescent transitions. The triplet states of Ir(III) complexes are advantageous over those of other transition metal complexes in that their electronic transitions and charge-transfer characteristics are tunable over wide ranges. These favorable properties suggest that Ir(III) complexes have significant potential in a variety of photofunctions other than electroluminescence. In this critical review, we describe recent photonic applications of novel Ir(III) complexes. Ir(III) complexes have been shown to affect the exciton statistics in the active layers of organic photovoltaic cells, thereby improving the photon-to-current conversion efficiencies. Nonlinear optical applications that take advantage of the strong charge-transfer properties of triplet transitions are also discussed. The tunability of the electrochemical potentials facilitates the development of efficient photocatalysis in the context of water photolysis or organic syntheses. The photoredox reactivities of Ir(III) complexes have been employed in studies of charge migration along DNA chains. The photoinduced cytotoxicity of Ir(III) complexes on live cells suggests that the complexes may be useful in photodynamic therapy. Potential biological applications of the complexes include phosphorescence labeling and sensing. Intriguing platforms based on cyclometalated Ir(III) complexes potentially provide novel protein tagging and ratiometric detection. We envision that future research into the photofunctionality of Ir(III) complexes will provide important breakthroughs in a variety of photonic applications.
环金属化铱(III)配合物的发展为电致发光带来了重要的突破，因为这类配合物可以有效地使三重激发态发生辐射跃迁。铱(III)配合物的三重态在性质上优于其他过渡金属配合物的三重态，因为它们的电子跃迁和电荷转移特性在很宽的范围内是可调谐的。这些有利的性质表明，铱(III)配合物在除电致发光以外的各种光功能中具有很大的潜力。在这篇评论中，我们描述了新型铱(III)配合物的最新光子应用。已经证明，铱(III)配合物可以影响有机光伏电池活性层中的激子统计，从而提高光子到电流的转换效率。还讨论了利用三重态跃迁强电荷转移特性的非线性光学应用。电化学势的可调谐性有助于在水分解或有机合成的背景下发展高效的光催化。铱(III)配合物的光还原反应活性已被用于研究沿 DNA 链的电荷迁移。铱(III)配合物对活细胞的光诱导细胞毒性表明，该配合物可能在光动力疗法中有用。该配合物的潜在生物学应用包括磷光标记和传感。基于环金属化铱(III)配合物的有趣平台可能为蛋白质标记和比率检测提供新的方法。我们设想，对铱(III)配合物光功能性的未来研究将为各种光子应用提供重要的突破。
