Novel functional tripodal monomolecular films

该提案的主要目标是根据单分子自组装的基本问题并考虑到潜在的应用，建立和优化一种新型的三脚架单分子膜--基于三聚三烯单元的功能自组装单分子膜(SAM)。该系统的体系结构明显不同于传统三脚架的四面体几何结构。该体系的优点是三聚三烯的自组装能力、三聚三烯骨架内高效的电子耦合、分子设计方面的灵活性，包括尾基的性质和数量、单分子组装时的密度以及这些部分的垂直取向。Triptycene支架将装饰合适的锚基，如硫醇或羧基，允许在三脚架吸附配置的金和银基质上有效地结合和自组装，单个苯环垂直于基质定向。这种基本的分子结构将被优化(例如，通过引入连接体)并用于进一步的官能化，其中一个或三个功能尾基分别连接在桥头或三脚架构型中。第一种构型允许相对较大的功能尾基的分离，例如用于点击反应的活性部位、用于特定结合生物分子(蛋白质等)的受体、分子开关和用于金属离子的配位，其优点是从所制备的模板开始具有强烈的空间效应抑制和灵活的超分子设计。第二种构型允许垂直于衬底定向的高密度的官能化尾基，只要使用偶极尾基，这对于界面偶极工程特别有用。不同的官能团将尝试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。在其他问题中，将在界面偶极工程、点击反应的效率以及分子内和分子间电荷转移的背景下对基于三茂铁的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、互补的表征实验，并使用最先进的计算工具对所制备的单分子膜的结构和性质进行建模。

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.