Minor modifications to the ligands surrounding a ruthenium complex lead to major differences in the way in which they catalyse the hydrogenation of arenes

The hydrogenation of benzene and other arenes under aqueous-organic biphasic conditions is evaluated using the ruthenium complexes Ru(eta(6)-C10H14)(pta)Cl-2 (pta=1,3,5-triaza-7-phosphaadamantane), Ru(eta(6)-C10H14)(tppts)Cl-2 (tppts=tris-3-sulfonatophenylphosphine trisodium salt) and Ru(eta(6)-C10H14)(pta)(2)Cl. The active catalysts formed during the hydrogenations correspond to a trinuclear cluster, a colloid and a mononuclear complex, respectively.