NDI‐Based Chiral Covalent Porphyrin Cages Constructed by Imine Condensation Reaction

Chiral imine cages featuring an aromatic cavity are developed employing naphthalene diimide and porphyrin subunits via imine condensation reaction. The structures are characterized by NMR, MALDI‐TOF mass spectrometry, UV–vis and, circular dichroism (CD) spectroscopy. Furthermore, the configuration of one type of the imine cage was confirmed by single‐crystal x‐ray diffraction. Self‐sorting studies were further performed. When different‐sized porphyrin monomers of equal molar amounts and naphthalene diimide ligands are mixed and subjected to self‐assembly reactions, two distinct types of porphyrin imine cages can be obtained. Aromatic guest coronene can be efficiently encapsulated within the imine cages, where coronene engages in supramolecular π–π interactions with the two porphyrin planes. This work constructs complex NDI‐based chiral covalent porphyrin cages using relatively simple precursor units, which are anticipated to find applications in fields like host–guest recognition and catalysis.