美国内布拉斯加大学林肯分校Jian Zhang团队报道了N,N '' -重卡唑和卟啉基混合配体金属-有机框架的对称导向合成用于光收集和能量转移研究。相关研究成果于2021年11月19日发表在国际知名学术期刊《美国化学会杂志》。

在过去的几十年中，人们曾多次尝试模拟光合作用中的能量转移（EnT），这是自然界中发生的一个关键过程，对太阳能燃料和可持续能源具有根本意义。金属-有机框架（MOFs）是一类新兴的多孔晶体材料，由有机连接体和金属或金属簇节点自组装而成，为探索定向EnT现象提供了理想的平台。然而，将能量供体和受体部分以原子精度放在同一框架内似乎是一个重大的合成挑战。

该文中，研究人员报道了一种高孔隙度和光活性的N，N′-双咔唑和卟啉基混合配体MOFs的设计和合成，即NPF-500-H2TCPP（NPF=Nebraska多孔骨架；H2TCPP=meso-tetrakis（4-羧基苯基）卟啉），其中，次级配体H2TCPP通过NPF-500底层（4,8）连接网络形成的八面体笼赤道平面的开放金属位点精确结合。用时间分辨光谱法捕捉了NPF-500-H2TCPP中从N，N′-双咔唑到卟啉的高效EnT过程，并以硫苯甲醚的光催化氧化为例。该结果不仅证明了NPF-500作为支架精确安排给体-受体组装用于EnT工艺的能力，而且还证明了直接利用EnT工艺进行光催化应用的潜力。

附：英文原文

Title: Symmetry-Guided Synthesis of N,N′-Bicarbazole and Porphyrin-Based Mixed-Ligand Metal–Organic Frameworks: Light Harvesting and Energy Transfer

Author: Christian Fiankor, James Nyakuchena, Rebecca Shu Hui Khoo, Xu Zhang, Yuchen Hu, Sizhuo Yang, Jier Huang, Jian Zhang

Issue&Volume: November 19, 2021

Abstract: In the past decades, many attempts have been made to mimic the energy transfer (EnT) in photosynthesis, a key process occurring in nature that is of fundamental significance in solar fuels and sustainable energy. Metal–organic frameworks (MOFs), an emerging class of porous crystalline materials self-assembled from organic linkers and metal or metal cluster nodes, offer an ideal platform for the exploration of directional EnT phenomena. However, placing energy donor and acceptor moieties within the same framework with an atomistic precision appears to be a major synthesis challenge. In this work, we report the design and synthesis of a highly porous and photoactive N,N′-bicarbazole- and porphyrin-based mixed-ligand MOF, namely, NPF-500-H2TCPP (NPF = Nebraska porous framework; H2TCPP = meso-tetrakis(4-carboxyphenyl)porphyrin), where the secondary ligand H2TCPP is incorporated precisely through the open metal sites of the equatorial plane of the octahedron cage resulting from the underlying (4,8) connected network of NPF-500. The efficient EnT process from N,N′-bicarbazole to porphyrin in NPF-500-H2TCPP was captured by time-resolved spectroscopy and exemplified by photocatalytic oxidation of thioanisole. These results demonstrate not only the capability of NPF-500 as the scaffold to precisely arrange the donor–acceptor assembly for the EnT process but also the potential to directly utilize the EnT process for photocatalytic applications.

DOI: 10.1021/jacs.1c10291

Source: https://pubs.acs.org/doi/10.1021/jacs.1c10291