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

A palladium-platinum bimetal complex containing a mono-lacunary α-Keggin-type polyoxotungstate is demonstrated. The bimetallic complex Cs 2.5 {Pd II (bpy)} 0.25 [α-PW 11 O 39 {Pd II (bpy)}{ cis -Pt II (NH 3 ) 2 }]·12H 2 O·2CH 3 CN (bpy = 2,2'-bipyridine) ( PdPt ) was synthesized by the reaction of Cs 4.9 K 0.1 [α-PW 11 O 39 { cis- Pt II (NH 3 ) 2 }]·10H 2 O ( Pt1 ) with Pd II (bpy)Cl 2 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 ( 1 H, 13 C, and 31 P) nuclear magnetic resonance spectroscopies. The coordination of { cis -Pt II (NH 3 ) 2 } and {Pd II (bpy)} moieties to the mono-vacant site of [PW 11 O 39 ] 7- resulted in an asymmetric, monomeric compound. A unique exchange reaction between the counter cation [Pd II (bpy)] 2+ and { cis -Pt II (NH 3 ) 2 } moiety in [α-PW 11 O 39 {Pd II (bpy)}{ cis -Pt II (NH 3 ) 2 }] 3- in a dimethylsulfoxide solution was also observed.