Gallium(III)- and Thallium(III)-Encapsulated Polyoxopalladates: Synthesis, Structure, Multinuclear NMR, and Biological Activity Studies.

Three gallium(III)- and thallium(III)-containing polyoxopalladates (POPs) have been synthesized and structurally characterized in the solid state and in solution, namely, the phosphate-capped 12-palladate nanocubes [XPdO(PO)] (X = Ga, ; X = Tl, ) and the 23-palladate double-cube [TlPdPO(OH)] (). The cuboid POPs, and , are solution stable as verified by the respective P, Ga, and Tl nuclear magnetic resonance (NMR) spectra. Of prime interest, the spin-spin coupling schemes allowed for an intimate study of the solution behavior of the Tl-containing POPs via a combination of P and Tl NMR, including the stoichiometry of the major fragments of . Moreover, biological studies demonstrated the antitumor and antiviral activity of and , which were validated to be as efficient as -platinum against human melanoma and acute promyelocytic leukemia cells. Furthermore, and exerted inhibitory activity against two herpetic viruses, HSV-2 and HCMV, in a dose-response manner.