Single Crystals of Insoluble Porous Salicylimine Cages

Porous organic cages (POCs) are meanwhile an established class of porous materials. Most of them are soluble to a certain extend and thus processable in or from solution. However, a few of larger salicylimine cages were reported to be insoluble in any organic solvents and thus characterized as amorphous materials. These cages were now synthesized as single-crystalline materials to get insight into packing motifs and preferred intermolecular interactions. Furthermore, the pairs of crystalline and amorphous materials for each cage allowed to compare their gas-sorption properties in both morphological states. Single crystal X-ray structures of three barely soluble triptycene based porous organic cages have been obtained and their crystal packing as well as gas sorption properties elucidated. The relation between crystallinity, porosity and gas adsorption selectivity was revealed for these porous structures.image

Automated summary

Porous organic cages are an important class of materials, with some being soluble while others are amorphous. This study synthesized single-crystalline materials of larger salicylimine cages, providing insights into their crystal packing and gas-sorption properties.