Designed Synthesis of Metal Cluster-Centered Pseudo-Rotaxane Supramolecular Architectures

The designed synthesis and structural characterization of two metal cluster-centered metallosupramolecular architectures are reported. In complex [(CF(3)SO(3))Ag(4)((t)BuC≡C)(Py8)](CF(3)SO(3))(2) (1) and [(CF(3)SO(3))Ag(4){C≡C-(m-C(6)H(4))-C≡C-(m-C(6)H(4))-C≡C-(m-C(6)H(4))-C≡C}Ag(4)(CF(3)SO(3))(Py8)(2)](CF(3)SO(3))(4) (2), organic acetylide ligands are utilized to induce the formation of polynuclear silver aggregates, which are encapsulated into the central cavity of the neutral macrocyclic compound azacalix[8]pyridine (Py8). The tetrasilver cluster centered [2]- and [3]-pseudo-rotaxane structures are obtained and fully characterized by X-ray crystallography, ESI mass spectrometry, and (1)H NMR spectroscopy.