SURFACE-MEDIATED ORGANOMETALLIC SYNTHESIS - PREPARATION OF [PT3(CO)6]N2- (N = 3, 4) BY THE CARBONYLATION OF PLATINUM COMPLEXES ON MGO UNDER CO AND CO + H-2

Treatment in CO or CO + H2 of samples prepared by adsorption of Pt(C3H5)2 on MgO leads to carbonylation reactions forming [Pt3(CO)6]n2- (n = 3, 4) on the MgO surface at room temperature. These anions can be extracted into solution by cation metathesis, giving efficient syntheses of the clusters. The surface-mediated synthesis can be directed to either anionic cluster. The reactivity is controlled by the basicity of the MgO surface and the gas environment. Similar surface organometallic chemistry takes place when the precursor is Na2PtCl6.6H2O, but higher temperatures (80-degrees-C) are required and mixtures are not always avoidable. The organometallic chemistry on the basic MgO surface is similar to that occurring in basic solution, discovered by Longoni and Chini.