Guest-Induced Molecular Capsule Assembly of <i>p</i>-Sulfonatothiacalix[4]arene

Two new compact molecular capsules of p-sulfonatothiacalix[4]arene with sodium ions have been synthesized by inducing suitable guest molecules, 1,2-bis(imidazol-1‘-yl)ethane or 2,2‘-bipyridine. Single-crystal X-ray diffraction analyses reveal that these supramolecular compounds possess open or close capsule conformations in a zigzag-like chain or a straight-line chain array. 1H NMR spectroscopic studies confirm that the above stable molecular capsules are present in solution. Their guest molecules in both compounds are well accommodated by p-sulfonatothiacalix[4]arene capsules via a variety of supramolecular interactions.