On-surface light-induced generation of higher acenes and elucidation of their open-shell character
On-surface light-induced generation of higher acenes and elucidation of their open-shell character
复制标题
DOI：
10.1038/s41467-019-08650-y
复制
发表时间：
2019-02
影响因子：
16.6
通讯作者：
José I. Urgel;Shantanu Mishra;H. Hayashi;J. Wilhelm;C. Pignedoli;Marco Di Giovannantonio;R. Widmer;M. Yamashita;Nao Hieda;P. Ruffieux;H. Yamada;R. Fasel
中科院分区：
文献类型：
--
作者：
José I. Urgel;Shantanu Mishra;H. Hayashi;J. Wilhelm;C. Pignedoli;Marco Di Giovannantonio;R. Widmer;M. Yamashita;Nao Hieda;P. Ruffieux;H. Yamada;R. Fasel
苯是一类重要的多环芳烃，由于其作为功能有机半导体的潜力，近年来引起了人们的极大关注。从根本上说，它们是研究一维极限下全碳sp2-骨架物理化学性质收敛的重要系统；由于具有之字形的边缘拓扑，它们也为探索石墨纳米结构中的磁性提供了一个肥沃的游乐场。因此，无论从基础还是从应用的角度来看，对大分子烯的研究都是势在必行的，但由于其较差的溶解性和较高的反应活性，传统的溶液化学合成方法阻碍了它们的合成。在这里，我们展示了在超高真空条件下，通过可见光诱导α-双二酮前体在Au衬底上的光解离，在表面上形成了庚烯和二十二烯。通过结合扫描隧道显微镜/光谱和非接触原子力显微镜的研究，再加上最先进的第一性原理计算，我们提供了对这些难以捉摸的化合物的化学和电子结构的洞察。
Acenes are an important class of polycyclic aromatic hydrocarbons which have recently gained exceptional attention due to their potential as functional organic semiconductors. Fundamentally, they are important systems to study the convergence of physico-chemical properties of all-carbonsp2-frameworks in the one-dimensional limit; and by virtue of having a zigzag edge topology they also provide a fertile playground to explore magnetism in graphenic nanostructures. The study of larger acenes is thus imperative from both a fundamental and applied perspective, but their synthesis via traditional solution-chemistry route is hindered by their poor solubility and high reactivity. Here, we demonstrate the on-surface formation of heptacene and nonacene, via visible-light-induced photo-dissociation of α-bisdiketone precursors on an Au(111) substrate under ultra-high vacuum conditions. Through combined scanning tunneling microscopy/spectroscopy and non-contact atomic force microscopy investigations, together with state-of-the-art first principles calculations, we provide insight into the chemical and electronic structure of these elusive compounds.