Novel functional tripodal monomolecular films

本提案的主要目标是基于单分子自组装的基本问题和潜在的应用，建立和优化一种新型的三足单分子膜-功能自组装单分子膜（SAMs）。该系统的结构与传统的三脚架部件的四面体几何结构明显不同。该体系的优点是：三萜烯的自组装能力，三萜烯框架内有效的电子耦合，分子设计的灵活性，包括尾部基团的性质和数量，单分子组装上尾部基团的密度，以及这些基团的垂直取向。三甲烯支架将用合适的锚基团（如硫醇或羧基）装饰，允许在金和银底物上以三脚架吸附结构进行有效的键合和自组装，单个苯环垂直于底物。这种基本的分子结构将被优化（例如通过引入连接剂）并用于进一步的功能化，分别以桥头堡或三脚架结构连接一个或三个功能尾基团。第一种结构允许相对较大的功能尾基团分离，如点击反应的活性位点、生物分子（蛋白质等）的特定附着受体、分子开关和金属离子的配位位点，具有强烈抑制的立体效应和从制造模板开始的灵活的超分子设计的优点。第二种结构允许高密度的垂直于衬底的功能尾基团，这对于界面偶极工程特别有用，只要使用偶极尾基团。将尝试不同的功能组来证明该方法的可能性、灵活性和可靠性，并为潜在的应用设计模型系统。除其他问题外，将在界面偶极子工程，点击反应效率以及分子内和分子间电荷转移的背景下对三甲烯基薄膜进行表征和优化。这项工作将与几个伙伴小组合作进行，进行必要的合成工作，补充表征实验，并使用最先进的计算工具对制造的单分子薄膜的结构和性能进行建模。

The major goal of the proposal is establishing and optimizing a new type of tripodal monomolecular films - functional self-assembled monolayers (SAMs), based on the triptycene unit - in context of fundamental issues of monomolecular self-assembly and in view of potential applications. The architecture of this system is distinctly different from the tetrahedral geometry of conventional tripodal moieties. The advantages of this system are the self-assembly ability of triptycene, efficient electronic coupling within the triptycene framework, flexibility in term of molecular design including the character and number of the tail groups, the density of thereof upon the monomolecular assembly, and upright orientation of these moieties. The triptycene scaffold will be decorated with suitable anchor groups, such as thiols or carboxyls, allowing efficient bonding and self-assembly on gold and silver substrates in tripodal adsorption configuration, with individual phenyl rings oriented perpendicular to the substrate. This basic molecular architecture will be optimized (e.g. by the introduction of the linkers) and used for further functionalization, with either one or three functional tail groups attached in either bridgehead or tripodal configuration, respectively. The first configuration allows a comparably large separation of the functional tail groups such as active sites for the click reaction, receptors for specific attachment of biomolecules (proteins, etc), molecular switches, and coordination sites for metal ions, with the advantages of strongly suppressed sterical effects and flexible supramolecular design starting from the fabricated template. The second configuration allows a high density of the functional tail groups directed perpendicular to the substrate, which can be in particular useful for interface dipole engineering, as far as dipolar tail groups are used. Different functional groups will be tried to prove the possibilities, flexibility, and reliability of the approach as well as to design model systems for potential applications. Among other issues, the triptycene-based films will be characterised and optimized in context of interface dipole engineering, efficiency of the click reaction, as well as intra- and intermolecular charge transfer. The work will be performed in collaboration with several partner groups, performing the necessary synthetic work, complementary characterization experiments, and modelling of the structure and properties of the fabricated monomolecular films with state-of-the-art computational tools.