Local vibronic and geometric structure of large organic adsorbates: New experimental approaches to chemisorption by STM-IETS and NIXSW

在这个项目中，我们将研究金属表面与复杂p-共轭有机吸附物之间的化学键。我们专注于内部的振动和几何结构的吸附物作为一个关键，以提高理解的化学吸附键。两个实验技术，迄今尚未得到充分利用，在这一领域，即STM为基础的非弹性隧穿光谱（IETS）和垂直入射X射线驻波技术（NIXSW），将被应用。在它们之间，它们应该允许（i）复杂分子实体的改进的（光谱）面内成像，（ii）具有高精度的结构键参数的元素特异性测定，以及（iii）在单分子水平和以下水平的化学吸附键的光谱表征，使得例如能够对共存的化学吸附状态进行逐分子区分以及它们之间的模式选择性切换。这些实验的结果将进行比较，从头算密度泛函计算的组合adsorbatessubstrate系统。所选择的方法将有助于发展的化学吸附模型，考虑到有机吸附物的扩展性，灵活性和多功能性。最后，将探索人工创建的纳米结构对有机吸附物的化学吸附性能的影响。

In this project we are going to investigate the chemical bond between metal surfaces and complex p-conjugated organic adsorbates. We focus on the internal vibronic and geometric structure of the adsorbate as a key to an improved understanding of the chemisorption bond. Two experimental techniques which have so far not been fully exploited in this field, namely STM-based inelastic tunnelling spectroscopy (IETS) and normal incidence X-ray standing wave techniques (NIXSW), will be applied. Between them, they should allow (i) improved (spectroscopic) inplane imaging of complex molecular entities, (ii) element-specific determination of structural bond parameters with high precision, and (iii) spectroscopic characterisation of the chemisorption bond at the level of single molecules and below, enabling e.g. the molecule-by-molecule distinction of coexisting chemisorption states and mode-selective switching between them. Results of these experiments will be compared to ab-initio density functional calculations of the combined adsorbatesubstrate system. The chosen approach will aid the development of chemisorption models that take the extended nature, flexibility and multifunctionality of organic adsorbates into account. Finally, the influence of artificially created nanostructures on chemisorption properties of organic adsorbates will be explored.