Selective MeCN/EtCN sorption and preferential inclusion of substituted benzenes in a cage structure with arylsulfonamide-armed anthraquinones

We report a series of crystal structures of arylsulfonamide-armed anthraquinones (AQs) (1-4). The arylsulfonamide-armed AQs formed orthogonal aromatic arrangements between the AQ unit and terminal aryl units due to well-defined intramolecular hydrogen bonding between the carbonyl units of AQs and the amino groups of sulfonamide units. Three disubstituted AQs 1-3 formed fundamental dimer structures, which were stabilized by intermolecular π-π interaction between AQs. Subtle differences in the dimer structures led to different packing structures. Among them, the 1,8-bis(arylsulfonamide) derivative (1) formed solvated crystals of 1·(MeCN), which exhibited reversible and selective MeCN and/or EtCN adsorption-desorption behavior. Tetra(arylsulfonamide) AQ (4) with four bulky substituents on its periphery formed various host-guest molecular crystals of 4·X₂ (X = toluene, xylene, trimethylbenzenes, 1,2,3,5-tetramethylbenzene, anisole, and benzonitrile) with a rectangular zero-dimensional cage surrounded by the π-planes of 4.