The π-magnetism of finite-sized nanoribbons occurring on the topological molecular interfaces remains largely unexplored due to limited experimental examples. Herein, we report a rational design, solution synthesis, and systematical characterization of a novel type of stair-like aza-nanographene (ANG) ANG-a/b with precise N-doping on the interfacial cove edges. Within the same molecular π-backbone, ANG-a had a closed-shell structure due to the electronic perturbation of cove-edge substitution, while ANG-b hosted a spin-polarized interface state, and its open-shell singlet diradicaloid structure produced a combined optoelectronic, magnetic, and physicochemical characteristic. Besides, dicationic ANG-b was also synthesized and characterized as a ground-state diradicaloid, again closely associated with the interfacial spin polarization in the charged π-system. Our studies might provide insights into future structural engineering of topological open-shell materials with robust yet exotic spin-polarized interface states.

由于有限的实验示例，在拓扑分子界面上出现的有限尺寸纳米带的 π 磁性在很大程度上仍未得到探索。在此，我们报告了一种新型阶梯状氮杂纳米石墨烯 (ANG) ANG-a / b的合理设计、溶液合成和系统表征，在界面凹凸边缘上具有精确的 N 掺杂。在同一分子 π 主链内，ANG-a由于凹边取代的电子扰动而具有闭壳结构，而ANG-b具有自旋极化界面态，其开壳单线态双自由基结构产生合并光电、磁和物理化学特性。此外，还合成了双阳离子ANG-b，并将其表征为基态双自由基，再次与带电 π 系统中的界面自旋极化密切相关。我们的研究可能会为具有稳健但奇异的自旋极化界面态的拓扑开壳材料的未来结构工程提供见解。