Huang Guo-Quan, Xia Ri-Qin, Chen Xu, Yang Hu, Huang Yong-Liang, Wu Kun, Zheng Ji, Lu Weigang, Li Dan
College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Supramolecular Coordination Chemistry, Jinan University, Guangzhou, Guangdong 510632, PR China.
Department of Chemistry, Shantou University Medical College, Shantou, Guangdong 515041, PR China.
J Am Chem Soc. 2025 Feb 26;147(8):6415-6426. doi: 10.1021/jacs.4c09907. Epub 2025 Feb 17.
Thermally stimulated delayed phosphorescence (TSDP) emission has recently been discovered in several Au(I)/Au(III) complexes, featuring thermally enhanced emission intensities and notable quantum yields (QYs). Developing earth-abundant metal-based TSDP emitters with further increased QYs holds significant promise for practical applications. Herein, we present a halogen bonding approach to achieve TSDP emission in bromo-substituted Cu(I) cyclic trinuclear complexes (CTCs). Photophysical analysis and theoretical calculations reveal the crucial role of halogen bonding in suppressing the excited-state distortions and reducing energy differences between the first and second triplet excited states (T and T). This enables efficient spin-allowed reverse internal conversion, leading to the TSDP behavior. Additionally, the low internal reorganization energy and rigid halogen-bonded network in bromo-substituted Cu(I) CTCs result in significantly suppressed nonradiative decay and high QYs, with one approaching near-unity. This work provides an innovative approach to extend the TSDP behavior from Au(I)/Au(III) to Cu(I) complexes with high QYs.
热激发延迟磷光（TSDP）发射最近在几种金（I）/金（III）配合物中被发现，其具有热增强的发射强度和显著的量子产率（QYs）。开发具有进一步提高量子产率的储量丰富的金属基TSDP发光体对实际应用具有重大前景。在此，我们提出一种卤键方法，以在溴取代的铜（I）环状三核配合物（CTCs）中实现TSDP发射。光物理分析和理论计算揭示了卤键在抑制激发态畸变以及减小第一和第二三重激发态（T₁和T₂）之间的能量差方面的关键作用。这使得自旋允许的反向内部转换得以有效进行，从而导致TSDP行为。此外，溴取代的铜（I）CTCs中低的内部重组能和刚性的卤键网络导致非辐射衰变显著受到抑制且量子产率很高，其中一个接近单位值。这项工作提供了一种创新方法，可将TSDP行为从金（I）/金（III）配合物扩展到具有高量子产率的铜（I）配合物。
