Mercaptothiacalixarenes Steer 24 Copper(I) Centers to form a Hollow‐Sphere Structure Featuring Cu 2 S 2 Motifs with Exceptionally Short Cu⋅⋅⋅Cu Distances

Tetramercaptotetrathiacalix[4]arene ( LH 4 ) can be used as a coordination platform to bind four Cu I ions at the thiolate and thioether S atoms. Donor ligands such as phosphanes can stabilize the resulting [LCu 4 ] units, which then remain monomeric ( [(Ph 3 PCu) 4 L] ). In the absence of donor ligands, they aggregate, providing a hexamer ( [LCu 4 ] 6 ) in high yields, with a hollow‐sphere structure formed by an unprecedented Cu 24 S 48 cage that is surrounded by the organic framework of the calixarene chalices. Preliminary NMR experiments with regard to the host‐guest chemistry in solution showed that the compound represents a polytopic host for acetonitrile and methane.