Coordination of Palladium(II) and Platinum(II) Complexes to One Vacant Site in an α-Keggin-Type Polyoxotungstate.

ABSTRACT

A palladium-platinum bimetal complex containing a mono-lacunary α-Keggin-type polyoxotungstate is demonstrated. The bimetallic complex Cs2.5{PdII(bpy)}0.25[α-PW11O39{PdII(bpy)}{cis-PtII(NH3)2}]·12H2O·2CH3CN (bpy = 2,2'-bipyridine) (PdPt) was synthesized by the reaction of Cs4.9K0.1[α-PW11O39{cis-PtII(NH3)2}]·10H2O (Pt1) with PdII(bpy)Cl2 in aqueous solution. The compound PdPt was characterized via elemental analysis, thermogravimetric/differential thermal analysis, and Fourier transform infrared, ultraviolet-visible, cold-spray ionization mass, and solution (1H, 13C, and 31P) nuclear magnetic resonance spectroscopies. The coordination of {cis-PtII(NH3)2} and {PdII(bpy)} moieties to the mono-vacant site of [PW11O39]7- resulted in an asymmetric, monomeric compound. A unique exchange reaction between the counter cation [PdII(bpy)]2+ and {cis-PtII(NH3)2} moiety in [α-PW11O39{PdII(bpy)}{cis-PtII(NH3)2}]3- in a dimethylsulfoxide solution was also observed.