Sun Guangchen, Wei Yu-Chen, Zhang Zhiyun, Lin Jia-An, Liu Zong-Ying, Chen Wei, Su Jianhua, Chou Pi-Tai, Tian He
Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science & Technology, 130 Meilong Road, Shanghai, 200237, P. R. China.
Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan R.O.C.
Angew Chem Int Ed Engl. 2020 Oct 12;59(42):18611-18618. doi: 10.1002/anie.202005466. Epub 2020 Aug 17.
Herein, we introduce the cyclic 8π-electron (C8π) molecule N,N'-diaryl-dihydrodibenzo[a,c]phenazine (DPAC) as a dual-functional donor to establish a series of new donor-linker-acceptor (D-L-A) dyads DLA1-DLA5. The excited-state bent-to-planar dynamics of DPAC regulate the energy gap of the donor, while the acceptors A1-A5 are endowed with different energy gaps and HOMO/LUMO levels. As a result, the rate and efficiency of the excited-state electron transfer vs. energy transfer can be finely harnessed, which is verified via steady-state spectroscopy and time-resolved emission measurements. This comprehensive approach demonstrates, for the first time, the manifold of excited-state properties governed by bifunctional donor-based D-L-A dyads, including bent-to-planar, photoinduced electron transfer (PET) from excited donor to acceptor (oxidative-PET), fluorescence resonance energy transfer (FRET), bent-to-planar followed by electron transfer (PFET), and PET from donor to excited acceptor (reductive-PET).
在此，我们引入环状8π电子（C8π）分子N，N'-二芳基 - 二氢二苯并[a，c]吩嗪（DPAC）作为双功能供体，以构建一系列新型供体 - 连接体 - 受体（D - L - A）二元化合物DLA1 - DLA5。DPAC的激发态从弯曲到平面的动力学调节供体的能隙，而受体A1 - A5具有不同的能隙和最高占据分子轨道/最低未占据分子轨道能级。结果，激发态电子转移与能量转移的速率和效率可以得到精细调控，这通过稳态光谱和时间分辨发射测量得到验证。这种综合方法首次展示了基于双功能供体的D - L - A二元化合物所支配的激发态性质的多样性，包括从弯曲到平面、从激发供体到受体（氧化 - PET）的光致电子转移（PET）、荧光共振能量转移（FRET）、从弯曲到平面随后的电子转移（PFET）以及从供体到激发受体（还原 - PET）。
