High-Throughput Screening and Automated Data-Driven Analysis of the Triplet Photophysical Properties of Structurally Diverse, Heteroleptic Iridium(III) Complexes
High-Throughput Screening and Automated Data-Driven Analysis of the Triplet Photophysical Properties of Structurally Diverse, Heteroleptic Iridium(III) Complexes
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DOI：
10.1021/jacs.0c12290
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发表时间：
2021-01-07
影响因子：
15
通讯作者：
Bernhard, Stefan
中科院分区：
文献类型：
--
作者：
DiLuzio, Stephen;Mdluli, Velabo;Bernhard, Stefan
测定了1440个通过组合平行合成制备的不同混配[Ir（CN）（2）（NN）]（+）配合物的稳态发射光谱和激发态寿命;发现72%的配合物是发光的，并且库的发射最大值跨越可见光谱（652-459 nm）。光谱分布范围从广泛的无结构带窄的排放表现出振动子结构。测得的激发态寿命范围在0.1-14 μ s之间。自动发射光谱拟合与连续高斯函数揭示了四个不同的测量类的激发态;除了充分理解的金属配体到配体电荷转移（（MLLCT）-M-3）和配体中心（（LC）-L-3）激发态，我们的分类还确定了较少探索的混合（MLLCT）-M-3/（LC）-L-3状态的物理特性。从DFT计算得到的电子结构特征上的一个大的子集，这些Ir（III）的发色团提供了清晰的洞察激发态的性质，并允许在这类常用的光催化剂的结构/发光关系的预测。在实验数据的基础上，建立了具有较高预测精度（R-2 = 0.89）的发光颜色模型。此外，不同程度的核重组的激发态显着影响发射能量和激发态寿命。
Steady state emission spectra and excited state lifetimes were measured for 1440 distinct heteroleptic [Ir(CN)(2)(NN)](+) complexes prepared via combinatorial parallelized synthesis; 72% of the complexes were found to be luminescent, and the emission maxima of the library spanned the visible spectrum (652-459 nm). Spectral profiles ranged from broad structureless bands to narrow emissions exhibiting vibrational substructure. Measured excited state lifetimes ranged between similar to 0.1-14 mu s. Automated emission spectral fitting with successive Gaussian functions revealed four distinct measured classes of excited states; in addition to well understood metal-ligand to ligand-charge transfer ((MLLCT)-M-3) and ligand-centered ((LC)-L-3) excited states, our classification also identified photophysical characteristics of less explored mixed (MLLCT)-M-3/(LC)-L-3 states. Electronic structure features obtained from DFT calculations performed on a large subset of these Ir(III) chromophores offered clear insights into the excited state properties and allowed the prediction of structure/luminescence relationships in this class of commonly used photocatalysts. Models with high prediction accuracy (R-2 = 0.89) for emission color were developed on the basis of experimental data. Furthermore, different degrees of nuclear reorganization in the excited state were shown to significantly impact emission energy and excited state lifetimes.