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

• Published in: Chemistry : a European journal 2019-07, Vol.25 (41), p.9658-9664
• Main Authors: Orłowski, Rafał, Cichowicz, Grzegorz, Staszewska‐Krajewska, Olga, Schilf, Wojciech, Cyrański, Michał K., Gryko, Daniel T.
• Format: Article
• Language: English
• Subjects: Aliphatic compounds; amides; Assembly; Benzene; Bonding strength; Chemistry; corroles; Coupling (molecular); Crystal structure; Crystallinity; Crystallization; Diamines; dyes; Ethylenediamine; Hydrogen; Hydrogen bonding; Hydrogen bonds; pigments; Pyridines; self-assembly; Solvation; Solvents; Toluene
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201901254

Four bis‐corroles linked by diamide bridges were synthesized through 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 the 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 the corrole rings. At the same time, both NHCO⋅⋅⋅NH corrole hydrogen bonds are intramolecular. In contrast, 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 the position 10‐meso. In solution, the hydrogen‐bonds pattern of the bis(amido‐corroles) is strongly affected by the type of the solvent. Compared with toluene (strongly high‐field shifted signals), DMSO and pyridine disrupt self‐assembly, whereas hexafluoroisopropanol strengthens intramolecular hydrogen bonds. It's a supra‐corrole: The choice of solvent has a significant influence on the hydrogen‐bonding motifs of bis(amido‐corroles) in both solution and the crystalline state. In solution, intramolecular hydrogen bonds can be broken by polar, aprotic solvents or strengthened by hexafluoroisopropanol. Weaker intermolecular hydrogen bonds, hydrogen bonds to solvents, and N−H⋅⋅⋅π interactions provide additional factors responsible for the conformation of molecules in the crystalline state.