Supramolecular Heteropolyoxopalladate {Pd15} Cluster Host Encapsulating a {Pd2} Dinuclear Guest: [PdII2-{H16-nPdII15O10(PO4)10}]n-

Ahigh-nuclearity polyoxopalladate compound, [PdII2⊂{H7PdII15O10(PO4)10}]9 {PdII17}, comprising a {Pd15} host occupied by a {Pd2} guest and the parent pristine “empty” [H7PdII15O10(PVO4)10]13 {Pd15} cluster have both been prepared and characterized by single-crystal X-ray crystallography, 31P NMR, CSI-MS, and XPS. The encapsulated {Pd2} has a short PdII PdII distance within the {Pd15} host. Solution studies indicate that the empty host and filled guest complex are in equilibrium with each other, and UV titrations revealed a binding constant of ca. 103 for the guest PdII ions, with a binding stoichiometry of almost 2.