Aromatic and antiaromatic ring currents can reveal global electronic delocalization around the circumference of π-conjugated macrocycles, although these phenomena are poorly understood in large rings. Here, we present the template-directed synthesis of a fully π-conjugated cyclic porphyrin 12-mer consisting of six β,meso,β-edge-fused porphyrin dimers connected by six butadiyne bridges. The lowest energy π-π∗ absorption band of this partially fused nanoring is shifted far into the NIR, confirming strong π-conjugation around the circumference of the macrocycle. Investigation of the oxidized and reduced nanoring-template complex by ¹H and ¹⁹F NMR spectroscopy demonstrates the presence of coherent global (anti)aromatic ring currents, consistent with DFT calculations. The stronger π-conjugation enables global charge delocalization even at low levels of oxidation or reduction. These findings open new avenues for the engineering of cyclic molecular wires.

芳香环和反芳香环电流可以揭示 π 共轭大环周围的整体电子离域，尽管这些现象在大环中人们知之甚少。在这里，我们提出了完全π共轭环卟啉12聚体的模板定向合成，该十二聚体由六个通过六个丁二炔桥连接的β，内消旋，β-边缘融合的卟啉二聚体组成。该部分稠合纳米环的最低能量 π-π* 吸收带远移至近红外区，证实了大环圆周周围的强 π 共轭。通过 ¹ H 和 ¹⁹ F NMR 光谱对氧化和还原的纳米环-模板复合物的研究表明存在相干的整体（反）芳香环电流，这与 DFT 计算一致。即使在低水平的氧化或还原下，更强的 π 共轭也能实现全局电荷离域。这些发现为环状分子线的工程开辟了新的途径。