Roy Indranil, Goswami Subhadip, Young Ryan M, Schlesinger Itai, Mian Mohammad Rasel, Enciso Alan E, Zhang Xuan, Hornick Jessica E, Farha Omar K, Wasielewski Michael R, Hupp Joseph T, Stoddart J Fraser
School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
J Am Chem Soc. 2021 Apr 7;143(13):5053-5059. doi: 10.1021/jacs.1c00298. Epub 2021 Mar 29.
The interaction of low-energy light with matter that leads to the production of high-energy light is known as photon upconversion. This phenomenon is of importance because of its potential applications in optoelectronics, energy harvesting, and the biomedical arena. Herein, we report a pillared-paddlewheel metal-organic framework (MOF), constructed from a tetrakis(4-carboxyphenyl)porphyrin sensitizer and a dipyridyl thiazolothiazole annihilator, designed for efficient triplet-triplet annihilation upconversion (TTA-UC). Single-crystal X-ray diffraction studies reveal that the Zn-metalated sensitizers are coordinated to Zn nodes in a paddlewheel fashion, forming 2D sheets, to which are linked annihilators, such that each sensitizer is connected to five of them. The precise arrangements of sensitizers with respect to annihilators, and the high annihilator-to-sensitizer ratio, facilitate Dexter energy transfer. This level of organization in an extended structure leads to a high TTA-UC efficiency of 1.95% (theoretical maximum = 50%) at an excitation power density of 25 mW cm.
低能量光与物质相互作用产生高能量光的现象被称为光子上转换。由于其在光电子学、能量收集和生物医学领域的潜在应用，这一现象具有重要意义。在此，我们报道了一种柱状桨轮金属有机框架（MOF），它由四（4-羧基苯基）卟啉敏化剂和二吡啶噻唑并噻唑湮灭剂构建而成，专为高效三重态-三重态湮灭上转换（TTA-UC）而设计。单晶X射线衍射研究表明，锌金属化的敏化剂以桨轮方式与锌节点配位，形成二维片层，湮灭剂连接到该片层上，使得每个敏化剂与五个湮灭剂相连。敏化剂相对于湮灭剂的精确排列以及高湮灭剂与敏化剂比例，促进了德克斯特能量转移。这种在扩展结构中的组织水平在25 mW cm的激发功率密度下导致了1.95%的高TTA-UC效率（理论最大值 = 50%）。
