Sun Qiang, Mateo Luis M, Robles Roberto, Lorente Nicolas, Ruffieux Pascal, Bottari Giovanni, Torres Tomás, Fasel Roman
nanotech@surfaces Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland.
Materials Genome Institute, Shanghai University, 200444, Shanghai, China.
Angew Chem Int Ed Engl. 2021 Jul 12;60(29):16208-16214. doi: 10.1002/anie.202105350. Epub 2021 Jun 14.
Porphyrin nanotapes (Por NTs) are promising structures for their use as molecular wires thanks to a high degree of π-conjugation, low HOMO-LUMO gaps, and exceptional conductance. Such structures have been prepared in solution, but their on-surface synthesis remains unreported. Here, meso-meso triply fused Por NTs have been prepared through a two-step synthesis on Au(111). The diradical character of the on-surface formed building block PorA , a phenalenyl π-extended Zn Por, facilitates intermolecular homocoupling and allows for the formation of laterally π-extended tapes. The structural and electronic properties of individual Por NTs are addressed, both on Au(111) and on a thin insulating NaCl layer, by high-resolution scanning probe microscopy/spectroscopy complemented by DFT calculations. These Por NTs carry one unpaired electron at each end, which leads to magnetic end states. Our study provides a versatile route towards Por NTs and the atomic-scale characterization of such tapes.
卟啉纳米带（Por NTs）因其高度的π共轭、低的HOMO-LUMO能隙和出色的导电性，有望用作分子导线。此类结构已在溶液中制备，但它们的表面合成仍未见报道。在此，通过在Au(111)上进行两步合成制备了中-中三稠合卟啉纳米带。表面形成的结构单元PorA（一种并苯烯基π扩展的锌卟啉）的双自由基特性促进了分子间的自偶联，并使得形成横向π扩展的纳米带成为可能。通过高分辨率扫描探针显微镜/光谱结合DFT计算，研究了单个Por NTs在Au(111)和薄绝缘NaCl层上的结构和电子性质。这些Por NTs在两端各携带一个未配对电子，这导致了磁性末端态。我们的研究为制备卟啉纳米带以及对此类纳米带进行原子尺度表征提供了一条通用途径。
