Atropisomeric Chiral Probes to Study the Supramolecular Organization in Porphyrin Self‐Assemblies

A noncatalysed nucleophilic aromatic substitution was used to prepare the (bacterio)chlorophyll mimics 2 ‐Zn, 3 ‐Zn, 4 ‐Zn and 5 ‐Zn. The localisation of the two recognition groups on the same side of the porphyrin macrocycles in 2 ‐Zn, 4 ‐Zn and 5 ‐Zn produces, through metal–ligand interactions, oligomers that display both H‐ and J‐type aggregates. These supramolecular architectures were confirmed by the introduction of optically pure atropisomers in 5 ‐Zn, which produces chiral aggregates. The UV/Vis and electronic circular dichroism spectra of all aggregates are used to propose an excitonic splitting mode that would correspond to this dual type of chromophoric self‐assembly.