Energy and Electron Transport in pi-Stacked Multichromophoric Assemblies: Global Dynamics from the Gas to Condensed Phase

在这个由化学系的大分子、超分子和纳米化学项目资助的项目中，马奎特大学的Rajendra Rathore和Scott Reid教授将研究包含堆叠的多环芳烃的模型分子组装。这种相互作用是许多分子组装体的特征，包括自然界中发现的那些（例如，DNA），并通过这种组件的电子和能量的传输的理解是至关重要的，以开发新的电荷转移材料的提高效率的应用在光伏器件，分子电子学和纳米技术。 为了应对这一挑战，进行了精心设计的分子组装的合成，并使用基于分子光谱学的各种实验策略，由计算化学支持的组件的特征。超分子组装利用各种共价和非共价支架相互作用。 其中，π堆叠是重要的。在光伏器件的导电层中的长程电荷转移的效率不仅由通过聚合物主链的分子内电子传输决定，而且由通过本体材料的分子间电子传输决定，其中π-共轭分子的无定形组装通常是随机的。 由于类环芳族二聚体和它们的阳离子基团代表了负责散装材料中电荷传输的最简单的基本单元，现代有机材料的分子电子学和纳米技术的新兴领域的设计和合成需要对精心设计的共面排列分子中的电子和能量转移过程有透彻的了解。 该项目解决了关于模型multichromophoric系统中的能量流和电子转移的基本问题，并开发了利用这种组件作为光驱动致动器的新策略，利用了伴随氧化或电子激发的分子重排。 通过研究更广泛的影响，这项工作为分子电子学和光电子学领域应用的下一代有机材料的设计和合成提供了信息。

In this project funded by the Macromolecular, Supramolecular and Nanochemistry program of the Chemistry Division, Professors Rajendra Rathore and Scott Reid of Marquette University will examine model molecular assemblies that incorporate stacked polycyclic aromatic hydrocarbons. Such interactions are characteristic of many molecular assemblies, including those found in nature (e.g., DNA), and an understanding of the transport of electrons and energy through such assemblies is critical to develop new charge-transfer materials of increased efficiency for applications in photovoltaic devices, molecular electronics, and nanotechnology. To meet this challenge, the synthesis of carefully designed molecular assemblies is carried out, and the assemblies characterized using a variety of experimental strategies based on molecular spectroscopy, supported by computational chemistry. Supramolecular assemblies exploit a variety of covalent and non-covalent scaffolding interactions. Of these, pi-stacking is important. The efficiency of long range charge transfer in the conducting layers of photovoltaic devices is governed not only by the intramolecular electron transport through the backbone of polymers but also by the intermolecular electron transport through bulk material, where the amorphous assembly of pi-conjugated molecules is generally randomized. As cyclophane-like aromatic dimers and their cation radicals represent the simplest fundamental units responsible for charge transport in bulk materials, the design and synthesis of modern organic materials for the emerging area of molecular electronics and nanotechnology demands a thorough understanding of electron and energy-transfer processes in carefully designed cofacially-arrayed molecules. This project addresses fundamental questions concerning the flow of energy and electron transfer in model multichromophoric systems and developes new strategies for exploiting such assemblies as light driven actuators, taking advantage of the molecular rearrangement which accompanies oxidation or electronic excitation. Examining broader impacts, this work informs the design and synthesis of next generation organic materials for applications in the area of molecular electronics and photovoltaics.