Rotationally Assisted Spin-State Inversion in Carbene-Metal-Amides Is an Artifact
Rotationally Assisted Spin-State Inversion in Carbene-Metal-Amides Is an Artifact
复制标题
DOI：
10.1021/acs.jpclett.7b02701
复制
发表时间：
2017-11-16
影响因子：
5.7
通讯作者：
Marian, Christel M.
中科院分区：
文献类型：
--
作者：
Foeller, Jelena;Marian, Christel M.
本函中提出的高级量子化学计算表明，Di等人最近观察到的高性能热激活延迟荧光发射体CMA 1的不寻常发光特性[Science 2017，356，159-163]可以在不诉诸这些作者提出的旋转辅助自旋状态反转机制的情况下进行解释。多组态和相对论效应导致快速和有效的热平衡的激发单重态和三重态人口的这种线性金配合物，即使是共面取向的配体。计算预测S-1（sic）T-1，系统间交叉超过亚微秒荧光2个数量级，从而淬灭提示荧光。在实验中观察到的CMA 1发光的显着的时间和环境依赖性的变化，归因于（受阻）溶剂重组的影响。
High-level quantum chemical calculations, presented in this Letter, show that the unusual luminescence properties of the high-performance thermally activated delayed fluorescence emitter CMA1, observed recently by Di et al. [Science 2017, 356, 159-163], can be explained without resorting to the rotationally assisted spin-state inversion mechanism proposed by these authors. Multiconfiguration and relativistic effects lead to fast and efficient thermal equilibration of the excited singlet and triplet populations of this linear gold complex even for coplanar orientations of the ligands. The calculations predict S-1(sic)T-1, intersystem crossing outcompetes the submicrosecond fluorescence by 2 orders of magnitude, thus quenching prompt fluorescence. The significant time- and environment-dependent shifts of the CMA1 luminescence, observed in experiment, are attributed to effects of (hindered) solvent reorganization.