A series of tetradentate Pt(II) emitters containing fused 5/6/6 metallocycles have been designed and synthesized. Molecular geometries play a critical role in determining the photophysical properties. Their emission spectra are significantly affected by the geometries of the molecular core skeletons, the substituents, even hydrogen atoms, and their positions, which are further supported by X-ray crystallographic analyses and theoretical calculations. The generation of excimer emissions is observed in the tetradentate 5/6/6 Pt(II) emitters for the first time and found to be concentration-dependent both in the solution and solid states. All of the Pt(II) emitters have high photoluminescent quantum efficiency of up to 100% and luminescent lifetime as short as 1.4 μs at room temperature, achieving a radiative rate of 7.14 × 10⁵ s^–1. Their emission color can be easily tuned to cover the whole visible region (λ_max = 464–632 nm) through selective synthetic modification of the heteroaromatic rings of the ligands. Pt(1-ptz)-based sky blue organic light-emitting diode (OLED) demonstrates a maximum external quantum efficiency (EQE) of 14.5%, yet maintains an EQE of 12.7% at a high brightness of 1000 cd/m². This work demonstrates that these tetradentate Pt(II) complexes can act as efficient phosphorescent emitters for OLED applications.

中文翻译：

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适用于高效磷光发射体和天蓝色OLED的四齿铂（II）配合物

已经设计并合成了一系列含有稠合5/6/6金属环的四齿Pt（II）发射极。分子几何形状在确定光物理性质中起关键作用。它们的发射光谱受到分子核心骨架的几何形状，取代基，甚至氢原子及其位置的显着影响，X射线晶体学分析和理论计算进一步支持了它们。第一次在四齿5/6/6 Pt（II）发射器中观察到准分子发射的产生，并且发现在溶液态和固态下均受浓度的影响。所有Pt（II）发射器在室温下均具有高达100％的高光致发光量子效率，且发光寿命短至1.4μs，实现了7.14×10的辐射率⁵ s ^–1。通过对配体的杂芳环进行选择性合成修饰，可以轻松调整它们的发射颜色以覆盖整个可见区域（_λmax = 464–632 nm）。基于Pt（1- ptz）的天蓝色有机发光二极管（OLED）的最大外部量子效率（EQE）为14.5％，但在1000 cd / m ²的高亮度下仍保持12.7％的EQE 。这项工作表明，这些四齿Pt（II）配合物可作为OLED应用的有效磷光发射体。