Concentration‐Dependent Self‐Assembly of an Unusually Large Hexameric Hydrogen‐Bonded Molecular Cage. Issue 13 (5th February 2021)

• Record Type: Journal Article
• Authors: Merget, Severin; Catti, Lorenzo; Zev, Shani; Major, Dan T.; Trapp, Nils; Tiefenbacher, Konrad
• Is Part Of: Chemistry. Volume 27:Issue 13(2021)
• Page Start: 4447
• Page End: 4453
• Publication Date: 2021-02-05
• Subjects: amides -- fullerenes -- host–guest complexes -- self-assembly -- supramolecular chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202005046
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The sizes of available self‐assembled hydrogen‐bond‐based supramolecular capsules and cages are rather limited. The largest systems have volumes of approximately 1400–2300 Å 3 . Herein, we report a large, hexameric cage based on intermolecular amide–amide dimerization. The unusual structure with openings, reminiscent of covalently linked cages, is held together by 24 hydrogen bonds. With a diameter of 2.3 nm and a cavity volume of ∼2800 Å 3, the assembly is larger than any previously known capsule/cage structure relying exclusively on hydrogen bonds. The self‐assembly process in chlorinated, organic solvents was found to be strongly concentration dependent, with the monomeric form prevailing at low concentrations. Additionally, the formation of host–guest complexes with fullerenes (C60 and C70 ) was observed. Abstract : A large, hexameric cage based on amide dimerization self‐assembles from a designed macrocyclic building block in nonpolar solvents. The unusually large structure ( V ∼2800 Å 3 ) features openings commonly associated with covalently linked cages and forms host–guest complexes with fullerenes (C60 and C70 ). The formation of the hexameric structure was found to be strongly concentration dependent.