ORGANOMETALLIC CHEMISTRY ON THE BASIC MAGNESIUM-OXIDE SURFACE - FORMATION OF [HIR4(CO)11]-, [IR6(CO)15]2-, AND [IR8(CO)22]2-

Samples prepared by adsorption of [Ir(CO)2(acac)] on partially dehydroxylated MgO and on hydrated MgO were treated in CO at room temperature to form supported [HIr4(CO)11]- and [Ir8(CO)22]2-, respectively. A sample prepared by adsorption of [Ir4(CO)12] on partially dehydroxylated MgO was treated with water-saturated helium at room temperature to form [Ir6(CO)15]2-on the MgO surface. Each of these anions was extracted in high yield into solution by cation metathesis with [PPN][Cl]. Consecutive formation of [HIr4(CO)11]-, [Ir8(CO)22]2-, and [Ir6(CO)15]2- on the MgO surface was observed as the temperature of the carbonylation reaction was increased from 25 to 200-degrees-C. The organometallic chemistry occurring on the basic MgO surface is similar to that occurring in basic solution.