Xiong Jinfan, Song Jia-Xi, Chang Xiaoyong, Song Xiu-Fang, Li Kai, Chen Yong
Key Laboratory of Photochemical Conversion and Optoelectronic Materials & CAS-HKU Joint Laboratory on New Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China.
University of Chinese Academy of Sciences, 100049, Beijing, PR China.
Chemistry. 2024 Oct 28;30(60):e202401203. doi: 10.1002/chem.202401203. Epub 2024 Oct 16.
Two-coordinate Au(I) complexes with a donor-metal-acceptor (D-M-A) structure have shown rich luminescent properties. However, charge-neutral dinuclear donor-metal-acceptor type Au(I) complexes featuring aurophilic interactions have been seldom explored. Herein, we describe the structures and photoluminescence properties of two dinuclear Au(I) complexes, namely DiAu-Ph and DiAu-Me. Single crystal X-ray structural analysis of DiAu-Ph reveals a short intramolecular Au-Au distance of 3.224 Å. In dilute solution and doped films, excitation wavelength dependent multiple phosphorescence phenomena were observed for these dinuclear complexes. Theoretical calculations reveal that the aurophilic interaction causes increased contribution of the Au d orbital to the highest occupied molecular orbitals. Thus, the gap between singlet and triplet excited states (ΔE) is enlarged, which disables the thermally activated delayed fluorescence (TADF). Moreover, the large energy separation (0.45-0.52 eV) and the different orbital configurations between the various excited states result in an inefficient internal conversion, accounting for their multiple phosphorescence properties.
具有供体-金属-受体（D-M-A）结构的二配位金（I）配合物展现出丰富的发光特性。然而，具有亲金相互作用的电中性双核供体-金属-受体型金（I）配合物却鲜有研究。在此，我们描述了两种双核金（I）配合物，即二金-苯基（DiAu-Ph）和二金-甲基（DiAu-Me）的结构及光致发光性质。二金-苯基的单晶X射线结构分析显示分子内金-金间距短至3.224 Å。在稀溶液和掺杂薄膜中，观察到这些双核配合物存在依赖于激发波长的多重磷光现象。理论计算表明，亲金相互作用使金d轨道对最高占据分子轨道的贡献增加。因此，单重态和三重态激发态之间的能隙（ΔE）增大，这使得热激活延迟荧光（TADF）无法发生。此外，各激发态之间较大的能量间隔（0.45 - 0.52 eV）以及不同的轨道构型导致内转换效率低下，这解释了它们的多重磷光性质。
