[Ir(N N N)(C N)L]+: A New Family of Luminophores Combining Tunability and Enhanced Photostability
[Ir(N N N)(C N)L]+: A New Family of Luminophores Combining Tunability and Enhanced Photostability
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DOI：
10.1021/ic402411g
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发表时间：
2014-02-03
影响因子：
4.6
通讯作者：
Bernhard, Stefan
中科院分区：
文献类型：
--
作者：
Chirdon, Danielle N.;Transue, Wesley J.;Bernhard, Stefan
相对未知的发光基团结构[Ir(N布尔AND N布尔AND N)(C布尔AND N)L](+) （N布尔AND N布尔AND N =三齿聚吡啶配体，CN = 2-苯基吡啶衍生物，L =单齿阴离子配体）提供了三齿聚吡啶配体的稳定性以及三种自变量配体的可调性。在这里，基于先前报道的化合物[Ir(tpy)(ppy)Cl](+) （tpy = 2,2':6',2”-三吡啶和ppy = 2-苯基吡啶）制备了一个新的发光基团。配合物以单一立体异构体的形式获得，配体的几何形状通过x射线晶体学得到明确的分配。材料的电化学分析表明，通过ppy功能化和单齿配体场强的改变，容易实现HOMO调制。当氯化物被氰化物取代时，发射也反映出类似的从橙色到绿蓝色的调制变化。许多新化合物表现出令人印象深刻的室温磷光，寿命接近3 μ s，量子产率达到28.6%。新型发光团作为光催化制氢光敏剂的应用表明，与常用的[Ir(ppy)(2)(bpy)](+) （bpy = 2,2′-联吡啶）光敏剂相比，它们在配位溶剂中的光稳定性得到了提高。然而，在循环伏安法和质谱法的氧化还原过程中，它们的单齿配体的结合成为不稳定的来源。对所有化合物的电子结构进行了DFT建模，以阐明实验性质。
The relatively unexplored luminophore architecture [Ir(N boolean AND N boolean AND N)(C boolean AND N)L](+) (N boolean AND N boolean AND N = tridentate polypyridyl ligand, CN = 2-phenylpyridine derivative, and L = monodentate anionic ligand) offers the stability of tridentate polypyridyl coordination along with the tunability of three independently variable ligands. Here, a new family of these luminophores has been prepared based on the previously reported compound [Ir(tpy)(ppy)Cl](+) (tpy = 2,2':6',2 ''-terpyridine and ppy = 2-phenylpyridine). Complexes are obtained as single stereoisomers, and ligand geometry is unambiguously assigned via X-ray crystallography. Electrochemical analysis of the materials reveals facile HOMO modulation through ppy functionalization and alteration of the monodentate ligand's field strength. Emission reflects similar modulation shifting from orange to greenish-blue upon replacement of chloride with cyanide. Many of the new compounds exhibit impressive room temperature phosphorescence with lifetimes near 3 mu s and quantum yields reaching 28.6%. Application of the new luminophores as photosensitizers for photocatalytic hydrogen generation reveals that their photostability in coordinating solvent is enhanced as compared to popular [Ir(ppy)(2)(bpy)](+) (bpy = 2,2'-bipyridine) photosensitizers. Yet, the binding of their monodentate ligand emerges as a source of instability during the redox processes of cyclic voltammetry and mass spectrometry. DFT modeling of electronic structure is provided for all compounds to elucidate experimental properties.