中国科学技术大学李玥琪团队研究了反芳香[4]环二苯并戊二烯单分子纳米环的双态双极性电荷输运。相关论文于2025年5月19日发表在《美国化学会杂志》上。

反芳香族化合物因其窄的最高占据分子轨道（HOMO）-最低未占据分子轨道的（LUMO）间隙、高反应性和增强的电荷迁移率而备受关注，但它们在单分子电子学中的作用尚不清楚。使用电化学控制扫描隧道显微镜断裂结（ECSTM-BJ）测量，研究组比较了芳香族[10]环对苯撑（[10]CPP）和反芳香族[4]环二苯并戊烯（[4]CDBP）的能量排列依赖电导。 

[10]CPP通过HOMO显示出单一的电导态，[4]CDBP显示出涉及HOMO和LUMO的两种不同状态。该分析和DFT计算将这种双态行为归因于窄HOMO-LUMO能隙内的独特锚定模式和能级重新排列。这一特性使得电子和空穴主导的路径依赖于锚定配置，并在固定栅极电势下共存。这种现象也在[4]CDBP⊃C60结构中观察到，突显了反芳香分子在先进分子电子学中的潜力。

附：英文原文

Title: Dual-State Ambipolar Charge Transport in Antiaromatic [4]cyclodibenzopentalene Single-Molecule Nanohoops

Author: Sai Feng, Renad Almughathawi, Andrej Weber, Songjun Hou, Chengyang Zhang, Jan S. Wssner, Birgit Esser, Colin Lambert, Qingqing Wu, Yueqi Li, Jinghong Li

Issue&Volume: May 19, 2025

Abstract: Antiaromatic compounds are of great interest due to their narrow highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps, high reactivity, and enhanced charge mobility, yet their role in single-molecule electronics is still not well understood. Using electrochemically controlled scanning tunneling microscopy break junction (ECSTM-BJ) measurements, we compared the energy-alignment-dependent conductance of the aromatic [10]cycloparaphenylene ([10]CPP) and the antiaromatic [4]cyclodibenzopentalene ([4]CDBP). While [10]CPP showed a single conductance state via the HOMO, [4]CDBP exhibited two distinct states involving both the HOMO and LUMO. Our analysis and DFT calculations attribute this dual-state behavior to unique anchoring mode and energy-level realignment within a narrow HOMO-LUMO gap. This property enables electron- and hole-dominated pathways that depend on the anchoring configuration and coexist at a fixed gate potential. This phenomenon, also observed in the [4]CDBPC60 structure, highlights the potential of antiaromatic molecules for advanced molecular electronics.

DOI: 10.1021/jacs.4c17115

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c17115