Covalently Linked Bis(Amido-Corroles): Inter- and Intramolecular Hydrogen Bond Driven Supramolecular Assembly.

Four bis-corroles linked via diamide bridges were synthesized via peptide-type coupling of a trans-A2B-corrole-acid with aliphatic and aromatic diamines. In the solid state, the hydrogen bond pattern in these bis-corroles is strongly affected by the type of solvent used in the crystallization process. Although intramolecular hydrogen bonds play a decisive role, they are supported by intermolecular hydrogen bonds and weak N-H∙∙∙π interactions between molecules of toluene and corrole cores. In an analogy to mono(amido-corroles), both in crystalline state and in solutions, the aliphatic or aromatic bridge is located directly above the corrole ring. When either ethylenediamine or 2,3-diaminonaphthalene are used as linkers, incorporation of polar solvents into the crystalline lattice causes a roughly parallel orientation of corrole rings. At the same time both NHCO…NH corrole hydrogen bonds are intramolecular. On the other hand solvation in toluene causes a distortion with one of the hydrogen bonds being intermolecular. Interestingly, intramolecular hydrogen bonds are always formed between the -NHCO- functionality located further from the benzene ring present at position meso-10. In solution the hydrogen bonds pattern of the bis(amido-corroles) is strongly affected by the type of the solvent. Compared to toluene (strongly high field shifted signals), DMSO and pyridine disrupt self-assembly, whereas hexafluoroisopropanol strengthens intramolecular hydrogen bonds.