Rational Synthesis of non-classical Nanographenes via Cyclodehydrofluorination Algorithm

对非经典纳米石墨烯（含有非六边形环、多螺旋和/或多孔系统的超大多环芳烃）的兴趣激增，源于对这些材料在下一代技术和未来电子产品中可能应用的巨大期望。然而，研究和广泛应用仍然是难以捉摸的，因为这类分子仍然缺乏容易获得的途径。因此，开发新的有效的合成方法来处理这类独特的材料似乎是该领域的中心任务。本项目的目的是基于C-F键激活方法开发非经典NGs的简易合成途径。所提出的策略依赖于本小组开发的环脱氢氟化（CDHF）高效芳基-芳基偶联技术。我们已经发现，在温和的条件下，通过在热活化氧化铝上激活C-F键，可以有效地实现分子内芳基-芳基偶联。在第一个阶段，我们成功地证明了我们的方法合成纳米石墨烯和包括功能性巴克碗和富勒烯在内的应变测地系统的可行性。在高选择性和频繁定量转换中，CDHF提供了通过执行合理内置于前驱耦合算法的多米诺骨牌式耦合（HF-zipping）的可能性。这为前驱体的设计提供了必要的灵活性，并允许用一锅分子内组装取代传统的逐步构建碳骨架。由于我们在合成实现多种CDHF算法的纳米结构方面取得了巨大成功，我们打算进一步研究这种反应，并开发一种用于各种非经典纳米结构的通用合成方法。我们的初步结果表明，非六边形环的合并和多螺旋NGs的构造是可行的。这为以完全可控的方式制备这些独特材料指明了道路。本项目拟通过C-F键活化合成螺旋形、碗形（含五边形）和鞍形（含七边形/八边形）nggs。这包括合理氟化前体的合成，然后压缩到所需的纳米结构。计划用光谱和电化学方法对各自的非经典纳米粒子进行研究。在这个项目的许多其他有趣的方面中，它打算进一步研究金属氧化物介导的冷凝机制。CDHF前所未有的高效率显示了其巨大的潜力，为实现本提案的目标提供了强有力的基础。初步的工作为解决难以捉摸的非经典天然气的简单合成挑战开辟了有希望的前景。

The exploding interest in non-classical nanographenes (extra-large PAHs containing non-hexagonal rings, multihelical and/or porous systems) originates from enormous expectations about the possible applications of these materials in the next generation technologiesand future electronics. However the investigation and widespread application have remained elusive since facile access to this class of molecules is still lacking. Therefore the development of new effective synthetic approaches to this unique class of materials appears to be the central task in the field. The aim of this project is to develop facilesynthetic routes to non-classical NGs based on the C-F bond activation approach. The proposed strategy is rely on highly effective Aryl-Aryl coupling technique via cyclodehydrofluorination (CDHF) developed in our group. Previously we have found that intramolecular Aryl-Aryl coupling can be realized effectively under mild conditions via C-F bond activation on thermally activated aluminum oxide. During the first period we have successfully demonstrated the feasibility of our approach for the synthesis of nanographenes and strained geodesic systems including functional buckybowls and fullerenes. Among the high selectivity and frequently quantitative Transformation the CDHF provides the possibility to perform a domino-like coupling(HF-zipping) via execution of the rationally built into a precursor coupling algorithm. This provides essential flexibility in the design of the precursor and allow superseding the conventional step-by-step construction of the carbon-skeleton by the one-pot intramolecularassembly. Because of our big success in the synthesis of nanostructures implementing multiple CDHF algorithm we intend to investigate this reaction further and to develop a general syntheticapproach to various non-classical NGs. Our preliminary results Show that facile incorporation of non-hexagonal rings and construction of multihelical NGs is feasible. This points the way to the preparative fabrication of these unique materials in a fully controllable manner. In this project the synthesis of helical, bowl-shaped (Pentagon containing) and saddle-shaped (heptagon/octagon containing) NGs via C-F bond activation is intended. This includes the synthesis of rationally fluorinated precursors followed by zipping to the desired nanostructures. The respective non-classical NGs are planned to be investigated with spectroscopic and electrochemical methods. Among many further interesting aspects of this project it is intended to investigate the mechanism of metal-oxide mediated condensationfurther. The unprecedentedly high efficiency of CDHF demonstrates the high potential and provides strong basis for achieving the objectives of this proposal. The preliminary work opens up promising vistas for tackling the challenge of facile synthesis of elusive nonclassicalNGs.