Functional Nanoloops: Strain-Promoted Modification of Acetylene-Containing Cycloparaphenylenes

功能性纳米环：含乙炔环对亚苯基的应变促进改性

• 批准号: 388027359
• 负责人: Dr. Tobias Andreas Schaub
• 金额: --
• 依托单位: Organisch-Chemisches Institut
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/388027359?language=en
• 关键词: Functional; Nanoloops; Strain; Promoted; Modification

The project aims to merge the highly topical research fields of cycloparaphenylenes (CPPs) with reactive acetylenes, to afford a library of functionalized CPP-derived nanoloops. The resulting scaffolds will be studied in-depth concerning their qualification as functional materials for application in organic electronics.The synthetic strategy relies on the transformation of a reactive acetylene moiety that is embedded within the CPP framework, into its corresponding ethylene derivative through cycloaddition chemistry with suitable partners. Indeed, preliminary density functional theory (DFT) calculations have shown a significant reduction of the inherent strain energy on going from the acetylene-incorporating CPP to its ethylene congener, which is predicted to provide for significant rate enhancements. The Strain-promoted transformations are grounded on well-established reactions within the realm of acetylene chemistry, such as Diels-Alder, [2+2]-cycloaddition-retroelectrocyclization or cyclotrimerization reactions that will allow the introduction of a broad variety of functional moieties into the macrocyclic CPP backbone. This approach will provide versatile access to tailored nanorings with appealing properties. The resulting compounds will serve e.g. as fluorescent components in organic light-emitting diodes or macrocyclic hosts for encapsulation of fullerene-type guests to foster energy/electron transfer processes.Beyond that, the acetylene-containing CPPs represent valuable molecular building blocks for the formation of covalent 2D networks on metal surfaces and in solutions. The strain-promoted functionalization approach will be applied to fabricate such carbon-rich 2D polymers with high structural precision on defined metal surfaces through thermal activation. The preparation and characterization of these 2D architectures will be carried out by scanning probe microscopy techniques (STM and AFM) supported by DFT calculations to corroborate the experimental results and gain deeper insight into electronic properties and band structures. Needless to say, such porous graphitic nanomaterials – highly topical, yet elusive targets – are not only vital for molecular-scale sensors, membranes and electronics, but also of fundamental scientific interest owing to their unique optoelectronic properties.In summary, the project not only tackles the current bottleneck of synthetic accessibility of functionalized CPP-derived entities, but also opens up an avenue towards versatile macrocyclic building blocks for host/guest studies and atomically defined 2D nanomaterials. As such, the results of the project will provide a fundamental and versatile tool to other researchers from different fields for the design and synthesis of unprecedented materials with tailored optoelectronic and material properties.

该项目旨在将环芳苯(CPP)和反应性乙炔的热门研究领域合并，以提供一个功能化的CPP衍生纳米环库。所得到的支架将被深入研究它们作为有机电子应用的功能材料的资格。合成策略依赖于通过与合适的伙伴进行环加成化学将嵌入在CPP框架中的反应性乙炔部分转化为其相应的乙烯衍生物。事实上，初步的密度泛函理论(DFT)计算表明，从乙炔-CPP到其乙烯同系物的固有应变能显著降低，预计这将提供显著的速率提高。菌株促进的转化基于乙炔化学领域内公认的反应，例如Diels-Alder反应、[2+2]-环加成-逆电环化反应或环三聚反应，这些反应将允许在大环CPP主链中引入广泛的功能部分。这种方法将提供多种多样的途径，以获得具有吸引人的特性的定制纳米材料。生成的化合物将作为有机发光二极管或大环主体的荧光成分，用于包裹富勒烯类型的客体，促进能量/电子转移过程。此外，含乙炔的CPP是在金属表面和溶液中形成共价2D网络的有价值的分子构建块。应变促进官能化方法将被用来通过热激活在定义的金属表面上制备这种具有高结构精度的富碳二维聚合物。这些2D结构的制备和表征将通过扫描探针显微镜技术(STM和AFM)在DFT计算的支持下进行，以证实实验结果并更深入地了解电子性质和能带结构。不用说，这种多孔性的石墨化纳米材料--非常热门，但又难以捉摸--不仅对分子规模的传感器、薄膜和电子学至关重要，而且由于其独特的光电性质而具有基础性的科学兴趣。总之，该项目不仅解决了目前官能化CPP衍生实体的合成可及性的瓶颈，而且为主客体研究和原子定义的2D纳米材料开辟了一条通向多功能大环构建块的道路。因此，该项目的成果将为来自不同领域的其他研究人员提供一个基本和通用的工具，用于设计和合成具有定制的光电和材料特性的前所未有的材料。