The structure-selective precise synthesis of carbon nanotubes (CNTs) has been long sought in materials science. The aromatic molecules corresponding to segment structures of CNTs, that is, carbon nanobelts (CNBs), are of interest as templates for CNT growth. Among the three types of CNB (armchair, chiral and zigzag CNBs), zigzag CNBs have been considered the most difficult type to synthesize. Here we report the synthesis, isolation and structural characterization of a zigzag CNB. The synthesis involves an iterative Diels–Alder reaction sequence followed by reductive aromatization of oxygen-bridged moieties. As predicted by theoretical calculations, this CNB was isolated as a stable compound. The structure of the zigzag CNB was fully characterized by X-ray crystallography and its wide energy gap with blue fluorescence properties was revealed by photophysical measurements. With synthetic strategies towards all three types of CNB in hand, the road to the precise synthesis of CNTs can now proceed to the next stage.

碳纳米管（CNT）的结构选择性精确合成长期以来一直在材料科学中寻求。与 CNT 的链段结构相对应的芳香分子，即碳纳米带 (CNB)，作为 CNT 生长的模板是令人感兴趣的。在三种类型的 CNB（扶手椅、手性和锯齿形 CNB）中，锯齿形 CNB 被认为是最难合成的类型。在这里，我们报告了锯齿形 CNB 的合成、分离和结构表征。该合成涉及迭代的 Diels-Alder 反应序列，然后是氧桥部分的还原芳构化。正如理论计算所预测的那样，这种 CNB 作为一种稳定的化合物被分离出来。X射线晶体学充分表征了锯齿形CNB的结构，光物理测量揭示了其具有蓝色荧光特性的宽能隙。有了针对所有三种 CNB 的合成策略，CNT 的精确合成之路现在可以进入下一阶段。