Zhang Hanjun, Chen Lichuan, Liu Xiaodong, Sun Fanxi, Zhang Maolin, Quintero Sergio Moles, Zhan Qian, Jiang Shenqing, Li Jiayu, Wang Dongsheng, Casado Juan, Hong Wenjing, Zheng Yonghao
School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, P. R. China.
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Sci Adv. 2024 Nov;10(44):eadp7307. doi: 10.1126/sciadv.adp7307. Epub 2024 Nov 1.
Uncovering the effects of radical injection into responsive organic molecules is a long-sought goal, and the single-molecule junctions provide a unique way to investigate molecular conductance evolution during the radical injection. We can modulate the main channel conductance by using electronic injection from off-site neutral radicals acting as gating terminals. Two families of cyclopentadienone derivatives were synthesized, featuring the inter-pyridyl main conductance channel and the inter-radical paths that are linear (FCF) or cross conjugated (PCP). Using a scanning tunneling microscope break junction technique, we find that the injection of mono- and diradicals in the PCP system unexpectedly decreases the conductance regarding the closed-shell analog, while that of FCF systems increases. Through-bond and through-space conductance mechanisms are found in the FCF and PCP series, respectively, and jointly modulate the overall charge transmission. This off-site injection concept offers a promising approach for developing molecular devices by manipulating electrical conductance in single-molecule junctions.
揭示向响应性有机分子中注入自由基的影响是一个长期追求的目标，而单分子结提供了一种独特的方式来研究自由基注入过程中分子电导的演变。我们可以通过使用来自作为门控终端的非原位中性自由基的电子注入来调节主通道电导。合成了两类环戊二烯酮衍生物，其特征在于吡啶间的主导电通道以及线性（FCF）或交叉共轭（PCP）的自由基间路径。使用扫描隧道显微镜断结技术，我们发现PCP系统中单自由基和双自由基的注入意外地降低了相对于闭壳类似物的电导，而FCF系统的注入则增加了电导。分别在FCF和PCP系列中发现了通过键和通过空间的电导机制，并共同调节整体电荷传输。这种非原位注入概念为通过操纵单分子结中的电导来开发分子器件提供了一种有前途的方法。
