Controlled Synthesis of Polyoxopalladates, and Their Gas-Phase Fragmentation Study by Electrospray Ionization Tandem Mass Spectrometry

Two new polyoxopalladates Na2H3[Pd12(3-SeO3)8(4-O)6(3-O)2Cr]25H2O (1) and Na8H7[Pd12(3-SeO3)8(4-O)8In]324H2O (2) have been synthesized by using Cr3+ and In3+ ions as structural directing agents. The two polyoxopalladates have been characterized by single-crystal X-ray diffraction (SXRD), FTIR and UV/Vis spectroscopy, elemental analysis (EA), ESI-MS, and thermogravimetric analysis (TGA). Detailed SXRD analysis combined with the ESI-MS and a collision-induced dissociation (CID) fragmentation study shows that the coordination configurations of the central ions are different; this affects the stability and fragmentation mechanism of the clusters in the gas phase. This approach may help us to understand the dissociation chemistry and the catalysis mechanism of polyoxopalladates.