Institut für Organische Chemie , Universität Würzburg , Am Hubland , 97074 Würzburg , Germany.
Center for Nanosystems Chemistry (CNC) , Universität Würzburg , Theodor-Boveri-Weg , 97074 Würzburg , Germany.
J Am Chem Soc. 2019 Aug 21;141(33):13008-13012. doi: 10.1021/jacs.9b06617. Epub 2019 Aug 7.
More than 50 years have passed since the first observation of graphitic cones in the pyrolysis of carbon. However, to date there has been no report in the literature on the synthesis of such carbon allotropes. Here we present the first synthesis of a carbon nanocone, which comprises a pentagon encircled by 30 hexagons, by means of a palladium-catalyzed cross-coupling reaction. In this synthetic approach, 15 C-C bonds were constructed from a cone-shaped aromatic scaffold, corannulene, and five naphthalene dicarboximide moieties through a cascade of [3 + 3] and [4 + 2] annulations. The conical geometry of the first synthetic carbon nanocone was confirmed by X-ray crystallography. The optical and electronic properties of this graphitic cone were elucidated by UV/vis and fluorescence spectroscopy and cyclic voltammetry.
自首次观察到碳热解过程中的石墨锥形物以来，已经过去了 50 多年。然而，迄今为止，文献中尚无关于此类碳同素异形物合成的报道。在这里，我们首次通过钯催化的交叉偶联反应，成功合成了一种由 30 个六边形环绕的五边形构成的碳纳米锥形物。在这种合成方法中，通过[3+3]和[4+2]环加成的级联反应，从锥形芳烃支架corannulene 和 5 个萘二酰亚胺部分构建了 15 个 C-C 键。通过 X 射线晶体学证实了第一个合成的碳纳米锥形物的锥形几何形状。通过紫外/可见和荧光光谱以及循环伏安法阐明了这种石墨锥形物的光学和电子性质。
