Novel functional tripodal monomolecular films

该提案的主要目标是建立和优化一种新型的三脚架单分子膜-功能性自组装单分子膜（SAMs），基于三蝶烯单元-在单分子自组装的基本问题的背景下，并鉴于潜在的应用。该系统的架构是明显不同于传统的三脚架部分的四面体几何形状。该系统的优点是三蝶烯的自组装能力，三蝶烯框架内的有效电子耦合，在分子设计方面的灵活性，包括尾基的性质和数量，其在单分子组装时的密度，以及这些部分的直立取向。三蝶烯支架将用合适的锚基团（例如硫醇或羧基）装饰，允许以三足吸附构型在金和银基底上有效结合和自组装，其中单个苯环垂直于基底取向。该基本分子结构将被优化（例如通过引入接头）并用于进一步官能化，其中一个或三个官能尾部基团分别以桥头或三脚架构型连接。第一种构型允许大规模分离功能性尾基，例如用于点击反应的活性位点、用于生物分子（蛋白质等）的特异性附着的受体、分子开关和金属离子的配位位点，具有强烈抑制的空间效应和从制造的模板开始的灵活的超分子设计的优点。第二种构型允许垂直于基底定向的高密度的官能尾部基团，只要使用偶极尾部基团，这对于界面偶极工程可以是特别有用的。不同的功能组将尝试证明的可能性，灵活性和可靠性的方法，以及设计模型系统的潜在应用。在其他问题中，基于三蝶烯的膜将在界面偶极工程、点击反应的效率以及分子内和分子间电荷转移的背景下进行表征和优化。这项工作将与几个合作伙伴小组合作进行，进行必要的合成工作，补充表征实验，并利用最先进的计算工具对制造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.