华中科技大学付英双团队近日研究了Pb（111）双层分子磁体的自稳定电荷态。相关论文于2025年7月7日发表在《美国化学会志》上。

电子充电在物理化学过程中起着关键作用，其在单分子中的固有稳定性是定制分子功能和开发分子器件所需要的，但在表面上仍然存在。

研究组发现在Pb（111）底物上生长的双（酞菁）铽（III） （TbPc₂）双层分子可以通过分子内畸变实现分子电荷态的自稳定。利用扫描隧道显微镜和光谱学，研究组确定了TbPc₂分子的部分减少到2倍对称，表现出能量分裂的分子轨道和两种不同的自旋态。

第一性原理计算揭示了对称减少是由带电触发的扬-泰勒扭曲引起的，这种扭曲将简并轨道提升为两个2倍对称轨道。低能轨道的单或双占位会导致不同的分子自旋态。与先前观察到的分子电荷状态相反，这种分子内畸变稳定地捕获了多余的电子，而没有衬底的明确参与。这些带电的单分子可以用尖端单独操纵。这项研究为调整分子的电荷和自旋态提供了一条新的途径。

附：英文原文

Title: Self-Stabilized Charge States in a Double-Decker Molecular Magnet on Pb(111)

Author: Xin Liao, Rui-Jing Sun, Emi Minamitani, Lian-Zhi Yang, Tao Xie, Wen-Hao Zhang, Chaofei Liu, Svetlana Klyatskaya, Mario Ruben, Ying-Shuang Fu

Issue&Volume: July 7, 2025

Abstract: Electron charging plays a key role in physicochemical processes, whose intrinsic stabilization in single molecules is desirable for tailoring molecular functionality and developing molecular devices, but remains elusive on surfaces. Here, we show that molecular charge states can be self-stabilized via intramolecular distortion in single bis(phthalocyaninato)terbium(III) (TbPc2) double-decker molecules, which were grown on the Pb(111) substrate. Using scanning tunneling microscopy and spectroscopy, we identify fractions of TbPc2 molecules that reduce to 2-fold symmetry, exhibiting energy-split molecular orbitals and two types of different spin states. Our first-principles calculations unveil that the symmetry reduction is induced by charging-triggered Jahn–Teller distortions, which lift the degenerate orbitals into two 2-fold symmetric orbitals. Single or double occupancy of the lower-energy orbital results in different molecular spin states. Such intramolecular distortion traps the excess electrons stably without explicit involvement of the substrate, in contrast to previously observed molecular charge states. These charged single molecules can be manipulated with the tip individually. This study offers a new avenue for tailoring the charge and spin states of molecules.

DOI: 10.1021/jacs.5c03347

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c03347