1,2,4,5-Tetrakis(phenylsulfonyl)benzene: a novel quadruped host with D2 symmetry having ordered sulfolane and cycloheptanone guests

The title tetrasulfone 1, in common with higher members of the multi-armed aromatic hosts, forms host–guest complexes with polar guest molecules. In the sulfolane and cycloheptanone complexes the host molecule possesses an abab conformation with exact C2, and approximate D2 symmetry with deviations owing to crystal packing forces. The conformation of the well-ordered cycloheptanone molecule, which normally undergoes facile pseudorotation, is unambiguously defined in the voids of the crystalline inclusion compound.