Porphyrin Nanorings

卟啉纳米环

• 批准号: EP/J007161/1
• 负责人: Harry Anderson
• 金额: $ 73.67万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FJ007161%2F1
• 关键词: Porphyrin; Nanorings

Conjugated organic materials are important because of their unique optical and electronic properties. For example organic semiconductors are finding applications in displays, flexible transistors and photovoltaic materials, while two-photon dyes are used in microfabrication, biological imaging and optical signal processing. This field has advanced tremendously during the past 20 years and provides excellent examples of the translation of fundamental science into practical applications that impact everyday life. However there are many open questions concerning the engineering and control of organic pi-systems. Fundamental studies are required to underpin further long-term technological innovations. In this proposal, we build on a new synthetic route to cyclic conjugated polymers, based on supramolecular organisation of precursor molecules. 'Vernier templating' is a new strategy for creating molecules with dimensions comparable to those of structures made by top-down engineering techniques, such as electron-beam lithography. The chemical synthesis of mesoscopic structures provides benefits through the introduction of functionality with atomic precision. We will exploit this methodology to study a previously unexplored region of structure-space and to generate completely new functional materials.Conjugated macrocycles or 'annulenes' have been a focus of research ever since the classical studies by Sondheimer in the 1960s. Large annulenes exhibit remarkable optoelectronic properties, and this has stimulated a resurgence of activity in the field. Anderson's group has contributed to the area by developing the template-directed synthesis of belt-like nanorings of 6, 8 or 12 porphyrin units, with diameters of 2-5 nm. This project will investigate the chemistry and physics of these nanorings, and extend the synthesis to even larger structures.The porphyrin nanorings targeted here are of great interest in their own right, owing to their similarity to natural light harvesting systems, and because they are expected to support the quantum coherent transport of charge and excitation. They also provide a new model system in which to explore the synthesis of mesoscopic molecules with well defined shapes. The templating procedures pioneered in Oxford are likely to stimulate developments in related fields such as molecular machines and biomimetic chemistry, where the controlled synthesis of large molecules with complex functionality remains a bottleneck for future developments. We focus on alkyne-linked metalloporphyrin oligomers as test systems which allow access to new functional materials. The fascinating interplay between synthesis, structure and function for these materials motivates the collaborative approach proposed here.Understanding the flow of energy and electrons through molecules is fundamental to many areas of science. We will investigating the delocalisation of energy and charge in nano-scale molecular wires with well defined tertiary structures. Conventional ring currents have only been observed in molecules with diameters of less than 2 nm, however semiconductor rings with diameters of about 10 nm exhibit persistent ring currents, in the absence of an applied voltage. These quantum-interference phenomena are analogous to the ring currents of aromatic molecules, except that they vary with the applied magnetic field (i.e. they exhibit Aharonov-Bohm oscillations). We will investigate whether molecular nanorings exhibit behaviour intermediate between those of small aromatic molecules and large quantum rings. Porphyrin nanorings resemble the light harvesting chlorophyll arrays which funnel energy into the reaction centre during photosynthesis. We will explore whether they mimic the excitonic behaviour of natural light harvesting arrays. Ultimately this work may lead to improved materials for solar power generation, or to molecular solenoids and split-ring resonators which function as optical metamaterials.

共轭有机材料因其独特的光学和电学性质而具有重要意义。例如，有机半导体在显示器、柔性晶体管和光伏材料中得到了应用，而双光子染料则被用于微制造、生物成像和光学信号处理。在过去的20年里，这一领域取得了巨大的进步，为将基础科学转化为影响日常生活的实际应用提供了极好的例子。然而，关于有机PI体系的工程和控制，仍有许多悬而未决的问题。需要进行基础研究，以支持进一步的长期技术创新。在这项提议中，我们建立了一条新的合成环状共轭聚合物的路线，基于前体分子的超分子组织。“游标模板化”是一种新的策略，可以制造出尺寸可与电子束光刻等自上而下工程技术制造的结构相媲美的分子。介观结构的化学合成通过引入具有原子精度的官能团提供了好处。我们将利用这种方法来研究一个以前从未探索过的结构-空间区域，并产生全新的功能材料。自20世纪60年代桑德海默的经典研究以来，共轭大环或‘环烯’一直是研究的焦点。大的环烯具有显著的光电性能，这刺激了该领域活动的复苏。安德森的团队开发了6、8或12个卟啉单元的带状纳米环的模板定向合成，直径为2-5 nm，为这一领域做出了贡献。这个项目将研究这些纳米环的化学和物理，并将合成扩展到更大的结构。由于它们与自然光捕获系统相似，并且它们有望支持电荷和激发的量子相干传输，因此这里所针对的卟啉纳米环本身就引起了极大的兴趣。它们还提供了一种新的模型系统，用于探索形状定义良好的介观分子的合成。牛津大学首创的模板程序可能会刺激分子机器和仿生化学等相关领域的发展，在这些领域，具有复杂功能的大分子的受控合成仍然是未来发展的瓶颈。我们将重点放在炔烃连接的金属卟啉齐聚物上，作为测试系统，使其能够获得新的功能材料。这些材料的合成、结构和功能之间令人着迷的相互作用激发了这里提出的合作方法。理解能量和电子在分子中的流动是许多科学领域的基础。我们将研究具有明确三级结构的纳米级分子线中的能量和电荷的离域。传统的环电流只在直径小于2 nm的分子中观察到，而直径约为10 nm的半导体环在没有外加电压的情况下表现出持续的环电流。这些量子干涉现象类似于芳香分子的环电流，不同之处在于它们随着外加磁场的变化而变化(即它们表现出Aharonov-Bohm振荡)。我们将研究分子纳米环是否表现出介于芳香小分子和大量子环之间的行为。卟啉纳米环类似于捕光的叶绿素阵列，在光合作用过程中将能量输送到反应中心。我们将探索它们是否模仿了自然光收集阵列的激子行为。最终，这项工作可能会改进用于太阳能发电的材料，或者导致用作光学超材料的分子螺线管和开环谐振器。

项目成果

Shadow Mask Templates for Site-Selective Metal Exchange in Magnesium Porphyrin Nanorings.

• DOI: 10.1002/anie.201804787
• 发表时间: 2018-06
• 期刊: Angewandte Chemie
• 作者: Pernille S Bols;H. Anderson

Breaking the Symmetry in Molecular Nanorings.

• DOI: 10.1021/acs.jpclett.5b02617
• 发表时间: 2016-01-21
• 期刊: The journal of physical chemistry letters
• 作者: Gong JQ;Favereau L;Anderson HL;Herz LM
• 通讯作者: Herz LM

Exciton-Exciton Annihilation as a Probe of Exciton Diffusion in Large Porphyrin Nanorings

• DOI: 10.1021/acs.jpcc.0c04546
• 发表时间: 2020-08-27
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY C
• 影响因子: 3.7
• 作者: Bressan, Giovanni;Jirasek, Michael;Meech, Stephen R.
• 通讯作者: Meech, Stephen R.

Template-Directed Synthesis of a Conjugated Zinc Porphyrin Nanoball

• DOI: 10.1021/jacs.8b02552
• 发表时间: 2018-04-25
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Cremers, Jonathan;Haver, Renee;Anderson, Harry L.
• 通讯作者: Anderson, Harry L.

Structure-Directed Exciton Dynamics in Templated Molecular Nanorings.

• DOI: 10.1021/acs.jpcc.5b00210
• 发表时间: 2015-03-19
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY C
• 影响因子: 3.7
• 作者: Gong, Juliane Q.;Parkinson, Patrick;Kondratuk, Dmitry V.;Gil-Ramirez, Guzman;Anderson, Harry L.;Herz, Laura M.
• 通讯作者: Herz, Laura M.