Controlled Functionality and Self-Assembly of PDI-Based Supramolecular Polymers by Targeted Modification

超分子聚合物由于具有聚合度可逆、自修复等优良的性质，在材料科学中是一个非常有前途的研究领域。超分子聚合领域中的当前挑战是缺乏对这些动态系统的结构（以及因此的功能）的控制。本项目的目的是探索各种策略，以改善控制的？因此，这些因素确保这些是有希望研究的化合物。在核上使用不同程度的硫化以探索对组装（由于硫化物质的空间结构的变化）和光电性质（例如，导致LUMO的降低和HOMO能级的增加，通过更快的三重态形成导致荧光猝灭，导致吸收最大值的红移）。在酰亚胺位置引入不同的基团以增强单体之间的不同非共价相互作用，例如多重氢键、芳族堆积和离子-离子相互作用，导致更快和更强的组装，或者通过引入空间位阻基团，加剧堆积。然而，由于在酰亚胺氮原子处的分子轨道中的节点，酰亚胺取代对电子性质的影响很小。此外，在bay位置的取代导致PDI核的平面性的扭曲，从而导致不同的堆叠行为。这种差异可用于调节自组装，另外，对PDI的光学性质的影响比对氮酰亚胺的取代大得多。预期的结果是获得对聚合物的官能团的长度、多分散性和位置的自组装行为的更多控制，该项目福尔斯EPSRC“物理科学”研究领域，更确切地说，属于“聚合物材料”小组，“合成有机材料”、“光子材料”和“能源应用材料”。

Supramolecular polymers (SMPs) are an interesting and promising field in material science, owing to their attractive properties, including reversible degree of polymerisation and self healability. A current challenge in the field of supramolecular polymerization is the lack of control over structure (and thus function) of these dynamic systems. The aim of this project is to explore various strategies to improve the control of perylene diimide (PDI)-based supramolecular polymers The choice of PDIs as the building blocks for this study is based on their high stability (thermal as well as chemical), high fluorescence quantum yield, which makes them favourable candidates for fluorescence imaging strong interactions between cores and their properties as N type semiconductors. These factors therefore ensure that these are promising compounds to investigate. Proposed routes to obtain the desired control are: The use of different degrees of thionation on the core to explore the influence on assembly (due to changes of the sterics of the thionated species) and optoelectronic properties (e.g., resulting in a decrease of the LUMO and increase of the HOMO energy levels, resulting in Fluorescence quenching by a faster triplet formation, resulting in a redshift of the absorption maxima). The introduction of different groups in the imide position to enhance different non covalent interactions between the monomers, e.g. multiple hydrogen bonding, aromatic stacking and ion-ion interactions, resulting in faster and stronger assembly, or by introducing sterically hindering groups, aggravating the stacking. However, the influence on the electronic properties by imide substitution is small, due to nodes in the molecular orbitals at the imide nitrogen atoms) Furthermore, substitution in bay position leads to a distortion of the planarity of the PDI core, resulting in a different stacking behaviour. This difference may be used to tune the self-assembly and, additionally, the effect on the optical properties of the PDI is much larger than substitution on the nitrogen imide.The expected outcome is to gain more control over the self-assembly behaviour regarding length, polydispersity and location of functional groups of the polymers, resulting in tuneable and customisable function and properties.This project falls within the EPSRC "Physical sciences" research area, more precisely in the subgroups "Polymer Materials", "Synthetic Organic", "Photonic Materials" and "Materials For Energy Application".