Host-Guest Chemistry in Discrete Polyoxo-12-Palladate(II) Cubes [MO 8 Pd 12 L 8 ] n - (M = Sc III , Co II , Cu II , L = AsO 4 3 - ; M = Cd II , Hg II , L = PhAsO 3 2- ): Structure, Magnetism, and Catalytic Hydrogenation.

A family of five host-guest assemblies comprising different metal ions inside a cuboid 12-palladium-oxo cage, [MOPdL] (, M = Sc, Co, Cu, L = AsO; M = Cd, Hg, L = PhAsO), was synthesized and structurally characterized in the solid state by single-crystal X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis, and their solution and gas-phase stability were validated by multinuclear NMR spectroscopy and electrospray-ionization mass spectrometry (ESI-MS). The polyoxopalladates (POPs) , , and represent the first three examples of the MPdAs archetype. The unique cubic ligand field of {MO} allows for collecting the speciation profiles of the POPs in solution using Sc and Cd NMR techniques. Detailed magnetic and electron paramagnetic resonance (EPR) studies were performed on . Catalytic studies on MPdAs (M = Cu and Co) supported on SBA-15 unveiled a guest metal-dependent structure-function relationship, with being the more efficient precatalyst for the hydroconversion of -xylene in a fixed-bed reactor.