Coexistence of Chiral and Achiral Adsorptions of Metal-Free Phthalocyanine Molecules on Cd(0001)
Coexistence of Chiral and Achiral Adsorptions of Metal-Free Phthalocyanine Molecules on Cd(0001)
复制标题
无金属酞菁分子在 Cd(0001) 上的手性和非手性吸附共存
DOI：
10.1021/acs.jpcc.0c07631
复制
发表时间：
2021
影响因子：
3.7
通讯作者：
Wang Jun-Zhong
中科院分区：
文献类型：
--
作者：
Ma Chao-Ke;Wang Ying;Shi Ming-Xia;Wang Ya-Ru;Sun Kai;Tao Min-Long;Yang Da-Xiao;Wang Zi-Long;Wu Zhi-Jian;Wang Jun-Zhong
我们报道了非手性酞菁（H2 Pc）分子在Cd（0001）表面的单分子手性和手性自组装。单轴有序已被发现在亚单层制度与个别H2 Pc分子对齐或不对齐的Cd（0001）的晶格方向。高分辨率STM图像显示，未对齐的分子在低偏压下表现出手性基序，在高偏压下表现出对称基序，而对齐的分子无论电压幅度如何都始终表现出对称对比度。第一性原理计算表明，所观察到的手性图案产生的电荷转移从基板到分子驱动的分子前线轨道的对称性破缺，而未对齐的H2 Pc的分子框架保持对称，没有结构畸变。此外，在长程有序区实现了具有风车状图案的手性酞菁自组装。这些结果对于了解手性结构和分子-基底相互作用之间的相互作用具有重要意义。
We report the single molecule chirality and chiral self-assembly of the achiral phthalocyanine (H2Pc) molecules on Cd(0001) surface. Uniaxial ordering has been found in the submonolayer regime with individual H2Pc molecules aligned or not aligned to the lattice directions of Cd(0001). High-resolution STM images show that the not-aligned molecules exhibit a chiral motif at low bias and a symmetric motif at high bias, whereas the aligned molecules always show a symmetric contrast regardless of the voltage amplitudes. First-principles calculations demonstrate that the observed chiral motifs arise from the symmetry break of molecular frontier orbitals driven by the charge transfer from substrate to molecule, while the molecular frames of not-aligned H2Pc remain symmetric without structural distortion. In addition, the chiral self-assembly of H2Pc with pinwheel-like patterns has been realized in the long-range order domain. These results are significant for understanding the interplay between chiral structures and molecule–substrate interaction.