Immobilization of organic molecules on metal surfaces and their coupling via thermally induced C–C bond formation is an important technique in organic and polymer synthesis. Using this approach, insoluble and reactive carbon nanostructures can be synthesized and the reactions monitored in situ using scanning probe microscopy methods. The diversity of conceivable products, however, is limited by the number and variety of known on-surface reactions. Here, we introduce the on-surface synthesis of polyarylenes by intermolecular oxidative coupling of isopropyl substituents of arenes. This [3+3] dimerization reaction forms a new phenylene ring and can be regarded as a formal cycloaromatization. The synthetic value of this reaction is proved by the synthesis of polyarylenes and co-polyarylenes, which we demonstrate by synthesizing poly(2,7-pyrenylene-1,4-phenylene). Scanning tunnelling microscopy and non-contact atomic force microscopy studies, complemented by density functional theory calculations, offer mechanistic insight into the on-surface cycloaromatization reaction.

有机分子在金属表面的固定化及其通过热诱导 C-C 键形成的耦合是有机和聚合物合成中的一项重要技术。使用这种方法，可以合成不溶性和反应性碳纳米结构，并使用扫描探针显微镜方法原位监测反应。然而，可想象的产品的多样性受到已知表面反应的数量和种类的限制。在这里，我们介绍了通过芳烃异丙基取代基的分子间氧化偶联来表面合成聚亚芳基。这种[3+3]二聚反应形成一个新的亚苯基环，可视为形式环芳构化。该反应的合成价值通过聚亚芳基和共聚亚芳基的合成证明，我们通过合成聚（2,7-芘-1，4-亚苯基）。扫描隧道显微镜和非接触原子力显微镜研究，辅以密度泛函理论计算，提供了对表面环芳构化反应的机理洞察。