FORMATION AND CHEMICAL-REACTIONS OF RUTHENIUM TRICARBONYLS ADSORBED ON METAL-OXIDES - USE OF CHEMICAL-REACTIONS AS A METHOD OF SURFACE-STRUCTURE DETERMINATION

The adsorption of Ru(CO)3Cl2(THF) onto the surface of hydroxylated metal oxides yields one of two surface metal carbonyls depending on the metal oxide. Depending on the nature of the metal oxide, the surface species either retains or loses coordinated chloride. The surface species may be described as [Ru(CO)3Cl2(HO-)] and [Ru(CO)3(HO-)(O-)2], where HO- and O- represent surface hydroxyl and oxo groups, respectively. Although the exact nature of the ligands provided by the surface remains unknown in the adsorbed complexes, the ligands shown provide for the formation of a neutral carbonyl fragment when ruthenium remains in the +2 oxidation state. The former species is generated on silica and NaY zeolite, and trie latter is generated upon adsorption on alumina and MgO. The proposed structures are consistent with the reactions of the surface species with bipyridine and tetracarbonylcobaltate(l-). The more strongly adsorbed species, [Ru(CO)3(HO-)(0-)2], generated on alumina and MgO does not react with tetracarbonylcobaltate(l-), while the more weakly adsorbed species, [Ru(CO)3Cl2(HO-)], on silica and NaY zeolite reacts to yield a bimetallic cluster. © 1990, American Chemical Society. All rights reserved.