Ordering aspects and intramolecular conformation of tetraphenylporphyrins on Ag(111)
Ordering aspects and intramolecular conformation of tetraphenylporphyrins on Ag(111)
复制标题
DOI：
10.1039/c004551a
复制
发表时间：
2010-01-01
影响因子：
3.3
通讯作者：
Marbach, Hubertus
中科院分区：
文献类型：
--
作者：
Buchner, Florian;Kellner, Ina;Marbach, Hubertus
用扫描隧道显微镜系统研究了室温下不同四苯基卟啉（xTPP）在Ag（111）上的自组装、分子内构象和超分子有序。研究涵盖了广泛的范围，即从低亚单层到多层的吸附行为被详细描述，并在分子-分子和分子-底物相互作用方面进行了结论性讨论。在单层覆盖下，分子自组装成由“t型”分子间相互作用引起的方形单元胞结构域，而结构域沿对称轴的方向由吸附物-底物相互作用决定。有趣的是，对于有序的单层结构，区域边界总是分离出不同组织手性的区域，但正方形单元胞的方向相同。这表明在特定的体系中，手性明显地限制了超分子TPP组装体的长程顺序。结合DFT计算还表明，先前报道的TPPs在吸附时的分子内鞍形变形在金属- tpp中比在2HTPP中更为明显。
A systematic scanning tunnelling microscopy study of the self-assembly, intramolecular conformation and supramolecular ordering of different tetraphenylporphyrins (xTPP) with or without a central metal atom (x = 2H, Fe, Co) on Ag(111) at room temperature is presented. The investigation covers a wide range, i.e. the adsorption behaviour from the low sub-monolayer up to the multilayer regime is described in detail and conclusively discussed in regard to molecule-molecule and molecule-substrate interactions. At monolayer coverage the molecules self-assemble in domains with a square unit cell caused by "T-type" intermolecular interactions, while the orientation of the domains along the symmetry axes is determined by adsorbate-substrate interactions. Interestingly for ordered monolayers domain boundaries always separate domains of different organizational chirality but same orientation of the square unit cell. This demonstrates that in the particular system chirality obviously restricts the long range order of the supramolecular TPP assemblies. In combination with DFT calculations it is also demonstrated that the previously reported intramolecular saddle shape deformation of TPPs upon adsorption is more pronounced for metallo-TPP than for 2HTPP.