| Abstract
| - The reductive carbonylation under 1 atm of CO and in the presence of surface basicity of silica-supported Na2[PtCl6], K2[PtCl4], [Pt(CH3CN)2Cl2], or [Pt(COD)Cl2] (COD = cis,cis-1,5-cyclooctadiene)leads to the formation in high yields of platinum carbonyl dianionic clusters [Pt3(CO)6]n2- (n = 6, 5, 4,3). Remarkably the silica surface plays a key role in these reductive carbonylations since no carbonylcluster is obtained by reductive carbonylation of solid Na2[PtCl6] in the absence of silica. The selectivityof the reaction can be easily tuned by controlling the surface metal loading, the basicity of the surface,and the nature of the platinum precursor (platinum oxidation state and nature of the coordination sphere).In particular, the one-step silica-mediated synthesis of [Pt18(CO)36]2- from K2[PtCl4] (90% yield) is veryconvenient when compared to the traditional synthesis in methanol solution (67% yield), which requirestwo steps: (i) formation of [Pt12(CO)24]2- and (ii) addition of Na2[PtCl6] drop by drop (molar ratio [Pt12(CO)24]2-:Na2[PtCl6] = 1:1) under a flow of CO.
- The reductive carbonylation under 1 atm of CO and in the presence of surface basicity of silica-supported Na2[PtCl6], K2[PtCl4], [Pt(CH3CN)2Cl2], or [Pt(COD)Cl2] leads to the formation in high yields of platinum carbonyl dianionic clusters [Pt3(CO)6]n2- (n = 6, 5, 4, 3). Remarkably the silica surface plays a key role in these reductive carbonylations since no carbonyl cluster is obtained by reductive carbonylation of solid Na2[PtCl6] in the absence of silica.
|
