The present research project focuses on the synthesis and structural characterization of new mono- and multinuclear organometallic complexes of ruthenium and palladium and on the study of their inherent catalytic potential for organic synthesis. Though being the cheapest of all noble metals, ruthenium and palladium have very promising catalytic features in particular for hydrogenation and for carbon-carbon coupling reactions. Within this project, we propose to work on three main topics which involve three Ph. D. students: Electron-Deficient Arene Ruthenium Clusters as highly selective olefin hydrogenation catalysts, Water-Soluble Organometallic Complexes as hydro¬genation or carbonylation catalysts in aqueous solution, and trans-Spanning Bi¬dentate Ligands for catalytic carbon-carbon and other coupling reactions.