Controlled Synthesis of Novel Functionalized Graphene Derivatives and Hybrid Structures

碳是独一无二的，是地球上生命的基础。许多关键技术，从药物输送到电子应用，都是以碳为基础的，它们使我们的现代文明成为可能。石墨烯具有独特的电子特性，是迄今为止性能最好的导电聚合物。然而，更重要的是石墨烯基面功能化的能力，这是一种允许引入特定功能的方法。我们成功地引入了氧化官能化石墨烯的受控化学，这种方法从水溶性前体薄片中产生高质量的石墨烯。在这个项目中，我们希望推进石墨烯功能化的化学方法，并致力于合成只有一个特定官能团的石墨烯衍生物，以减少这类材料的异质性。这种方法将导致对属性的更深入的理解。特别是，以氧官能化石墨烯为前驱体形成的C-C键将首次实现对产物功能和溶解度的控制，并可能成为未来开发高选择性传感器的基础。此外，还将进行氧化官能团石墨烯形成的机理研究，以确定其氧化官能团的氧源。这些知识对于避免或控制晶格缺陷的形成至关重要。我们将合成不同形状的功能带电pi体系，分别研究带电pi体系与石墨烯表面和氧功能化石墨烯表面的相互作用。光物理和电子性能的评估将揭示这些系统如何有助于选择性传感器，太阳能电池或透明和导电涂层的发展。静电和阳离子- π相互作用将被用来稳定溶液中的石墨烯或调节石墨烯的掺杂水平。评估分子与单个石墨烯薄片表面的相互作用以及电子性质的变化将由拉曼光谱和电子器件决定。这种方法可以量化掺杂的影响。获得的知识将有助于理解分层系统。分层结构将通过以下自组装策略构建。石墨烯衍生物和分子层的逐层结构将首次制备出具有特定功能的新型石墨插层化合物。刺激，如质子转移，将调节层状系统内石墨烯的电子特性。改变的电子性质随后与pH值有关。这些研究可能导致纳米级的电子pH传感器。本项目开展的基础研究将推动有机电子学研究领域的发展。

Carbon is unique and is the basis for life on earth. Many key-technologies, ranging from drug delivery to electronic applications, are based on carbon and make our modern civilization possible. Graphene has unique electronic properties and is outperforming conductive polymers by far. However, more important is the ability to functionalize the basal plane of graphene, an approach that allows introducing specific functions. We successfully introduced the controlled chemistry of oxo-functionalized graphene and this approach yields a high quality of graphene from flakes of water-soluble precursors. With this project, we want to advance the chemical methods for functionalization of graphene and aim on the synthesis of graphene derivatives with only one specific functional group to reduce the heterogeneity of this class of materials. This approach will lead to a deeper understanding of the properties. In particular, the C-C bond formation with oxo-functionalized graphene as precursor will give control over functionality and solubility of products for the first time and may be the basis to develop highly selective sensors in the future. Moreover mechanistic investigations for the formation of oxo-functionalized graphene will be conducted to identify the source of oxygen of its oxo-functionalities. That knowledge will be of utmost importance to either avoid or control the formation of lattice defects. We will synthesize functional charged pi-systems of different shape to study the interaction of the charged pi-systems with the surface of graphene and oxo-functionalized graphene, respectively. The evaluation of the photophysical and electronic properties will reveal how these systems can contribute to the development of selective sensors, solar cells or transparent and conductive coatings. The electrostatic and cation-pi interactions will be exploited to either stabilize graphene in solution or to tune the doping level of graphene. The evaluation of the molecular interaction with the surface of individual flakes of graphene and the change of electronic properties will be determined by Raman spectroscopy and in electronic devices. This approach allows quantifying the effect of doping. The gained knowledge will contribute to understand layered systems.Layered structures will be built by following self-assembly strategies. Layer-by-layer architectures of graphene derivatives and molecular layers will be prepared as novel graphite intercalation compounds with specific function for the first time. Stimuli, such as proton transfers will modulate the electronic properties of graphene inside the layered system. The changed electronic properties can subsequently related to pH values. These studies can lead to electronic pH sensors on the nm-scale. The basic investigations conducted in this project will advance the research field of organic electronics.