Formic Acid Dehydrogenation Catalysed by Ruthenium Complexes bearing the Tripodal Ligands Triphos and NP3

The selective formic acid dehydrogenation to a mixture of CO2 and H2 was achieved with moderate to good productivities in the presence of homogeneous Ru catalysts bearing the polydentate tripodal ligands 1,1,1-tris-(diphenylphosphinomethyl)ethane (triphos) and tris-[2-(diphenylphosphino)ethyl]- amine (NP3), either made in situ from suitable Ru(III) precursors or as molecular complexes. Preliminary mechanistic studies highlighting subtle differences due to ligand effects in the corresponding systems under study are also presented.