Synthesis of triple stranded porphyrin nanobelts
- Arnau Rodríguez-Rubio
- He Zhu
- Ka Man Cheung
- Igor Rončević
- Lene A. Gödde
- Janko Hergenhahn
- Joshua L. Field
- Prakhar Gupta
- Wojciech Stawski
- Henrik Gotfredsen
- Joseph Straw
- Matthew Edmondson
- James N. O’Shea
- Alex Saywell
- Harry L. Anderson
2025-10-17
Molecular nanobelts are fascinating analogs of carbon nanotubes. Their rigid geometries and strongly coupled π-electrons have the potential to generate a wave function resembling that of a quantum ring. Here, we report the synthesis of triple stranded nanobelts consisting of 8 to 12 edge-fused porphyrin units with diameters of 21 to 32 angstroms. We synthesized these nanobelts by nickel-mediated coupling of meso -bromoporphyrins to form singly linked nanorings, followed by oxidation with gold(III) chloride. Experimental 1 H nuclear magnetic resonance spectra, supported by computational simulations, revealed that belts containing odd numbers of porphyrins, with circuits of 90 or 110 π-electrons, display global aromatic ring currents, whereas even-numbered belts, with 80, 100, or 120 π-electrons, are globally antiaromatic.