Institut des Sciences de Matériaux de Mulhouse, CNRS-UMR 7361, Université de Haute Alsace, 3B, rue Alfred Werner, 68093 Mulhouse, France.
Nanoscale. 2014 Jul 21;6(14):8250-6. doi: 10.1039/c4nr00539b.
We studied the formation of hydrogen-bonded supramolecular polymers of Ethyl Hexyl Urea Toluene (EHUT) on a gold (111) surface by low temperature scanning tunneling microscopy. Tunneling spectroscopy performed along an individual molecule embedded in a self-assembled layer revealed strong changes in the value of the HOMO-LUMO gap. A variation of the LUMO state is attributed to the effect of space charge accumulation resulting from anisotropic adhesion of the molecule. In addition, for specific tunneling conditions, changes induced through the formation of hydrogen bonds became visible in the differential conductance (dI/dV) maps; isolated molecules, hydrogen bonded dimers and supramolecular polymers of EHUT were distinguishable through their electronic properties.
我们通过低温扫描隧道显微镜研究了乙基己基脲甲苯（EHUT）在金（111）表面形成氢键超分子聚合物的过程。在自组装层中嵌入单个分子进行隧道谱测量，揭示了 HOMO-LUMO 能隙值的强烈变化。LUMO 态的变化归因于分子各向异性粘附引起的空间电荷积累的影响。此外，对于特定的隧道条件，通过氢键形成诱导的变化在微分电导（dI/dV）图谱中变得可见；通过其电子特性可以区分孤立分子、氢键二聚体和 EHUT 的超分子聚合物。
