Chai Yongqiang, Liu Xiaolong, Wu Bo, Liu Liping, Wang Zhuan, Weng Yuxiang, Wang Chunru
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Am Chem Soc. 2020 Mar 4;142(9):4411-4418. doi: 10.1021/jacs.9b13376. Epub 2020 Feb 18.
Novel fullerene-based donor-acceptor (DA) dyads, ScN@C-PTZ and C-PTZ, have been synthesized and investigated in which the photoinduced electron transfer direction is proved to be switchable by regulating the redox state. In detailed photophysical experiments, reductive electron transfer from the PTZ moiety to ScN@C is confirmed with transient absorption (TA) spectroscopy in the neutral ScN@C-PTZ dyad. After oxidizing the PTZ moiety to PTZ in a reversible manner, oxidative electron transfer from the ScN@C moiety to the PTZ radical cation is corroborated experimentally and theoretically, leading to formation of a metastable charge transfer (CT) state (ScN@C)-PTZ, which is not observed in the C-PTZ dyad. To the best of our knowledge, this is the first time in situ tunable molecular photodiode-like behavior is fulfilled utilizing a fullerene dyad. These findings will contribute to the future application of fullerene-based DA conjugates in molecular electronic devices.
新型的基于富勒烯的供体-受体（DA）二元体系，ScN@C-PTZ和C-PTZ，已被合成并进行了研究，其中光致电子转移方向被证明可通过调节氧化还原状态来切换。在详细的光物理实验中，通过瞬态吸收（TA）光谱证实了在中性的ScN@C-PTZ二元体系中存在从PTZ部分到ScN@C的还原电子转移。以可逆方式将PTZ部分氧化为PTZ⁺后，从ScN@C部分到PTZ自由基阳离子的氧化电子转移在实验和理论上均得到了证实，导致形成了一种亚稳态电荷转移（CT）态（ScN@C）⁺-PTZ⁻，而在C-PTZ二元体系中未观察到这种情况。据我们所知，这是首次利用富勒烯二元体系实现原位可调的类分子光电二极管行为。这些发现将有助于基于富勒烯的DA共轭物在分子电子器件中的未来应用。
