厦门大学洪文晶团队报道了C-H···π相互作用下电荷输运的纳米尺度演化。相关研究成果于2024年11月25日发表于国际顶尖学术期刊《美国化学会杂志》。

C-H··π相互作用是一种普遍存在的分子间力，在化学、材料科学和生命科学中起着关键作用。尽管对它们对分子间结合构型和能量学的影响进行了广泛的研究，但它们对分子内耦合和电荷输运的影响仍未得到探索。

该文中，研究人员分别研究了由C-H··π和π-π相互作用连接的超分子结内的电荷输运，发现C-H·•π相互作用的电导率是π-π互相作用的3.5倍。

埃尺度距离依赖实验表明，C-H··π超分子结的电导在拉伸下经历初始衰减，随后逐渐收敛，这与π-π堆叠超分子结的周期性波动形成鲜明对比。

理论计算表明，C-H···π相互作用中的电荷输运在拉伸下从破坏性量子干涉转变为相长性量子干涉，与π-π堆积相比，相长量子干涉的范围更大。

该研究证实了C-H··π相互作用促进了有效的分子间电荷传输，并阐明了量子干涉效应随组装构型的演变，为超分子材料和器件的设计提供了关键的见解。

附：英文原文

Title: Nanoscale Evolution of Charge Transport Through C–H···π Interactions

Author: Yu Zhou, Shurui Ji, Yixuan Zhu, Huanhuan Liu, Juejun Wang, Yanxi Zhang, Jie Bai, Xiaohui Li, Jia Shi, Wenqiu Su, Ruiyun Huang, Junyang Liu, Wenjing Hong

Issue&Volume: November 25, 2024

Abstract: C–H···π interactions, a prevalent intermolecular force, play a pivotal role in chemistry, materials science, and life sciences. Despite extensive studies of their influence on intermolecular binding configurations and energetics, their impact on intermolecular coupling and charge transport remains unexplored. Here, we investigate the charge transport within supramolecular junctions connected by C–H···π and π–π interactions, respectively, and find that C–H···π interactions exhibit conductances that are 3.5 times those of π–π interactions. Angstrom-scale distance-dependent experiments indicate that the conductance of C–H···π supramolecular junctions experiences initial decay under stretching, followed by gradual convergence, in contrast with the periodic fluctuations in π–π stacked supramolecular junctions. Theoretical calculations show that charge transport within C–H···π interactions transitions from destructive to constructive quantum interference under stretching, with a larger range of constructive quantum interference compared with π–π stacking. This study establishes that C–H···π interactions facilitate efficient intermolecular charge transport and elucidates the evolution of quantum interference effects with assembly configuration, offering critical insights for the design of supramolecular materials and devices.

DOI: 10.1021/jacs.4c08975

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c08975