Synthesis, characterization and aqueous-biphase hydrogenation of olefins by the ruthenium complexes Ru(CO)3(TPPMS)2 and RuH2(CO)(TPPMS)3 Original Research Article

The new water-soluble ruthenium complexes Ru(CO)3(TPPMS)2 (I) and RuH2(CO)(TPPMS)3 (II), where TPPMS is the m-sulfophenyldiphenylphosphine (C6H5)P(m-C6H4SO3Na) in the sodium salt form, were prepared in highly purity content (90% for I and 95% for II) and characterized by using different spectroscopic techniques. These ruthenium complexes showed high stability and solubility in water, enough for using as a catalyst precursor in the two phase catalytic hydrogenation of 1-hexene, styrene, 1-decene, cyclohexene and allylbenzene under moderate reaction conditions. The similar reaction profile obtained during the hydrogenation of 1-hexene, when each complex are used separately, accompanied with the NMR analysis of the final aqueous phase when Ru(CO)3(TPPMS)2 (I) is used as a catalyst precursor, shows that the Ru(CO)3(TPPMS)2 (I) is transformed selectively to RuH2(CO)(TPPMS)3 (II) during the hydrogenation pathway. The mercury test in independent experiments showed no interference of the Hg with the evolution of the reaction, demonstrating that the catalysis is performed by molecular species and the recycling nature of this complexes is demonstrated during the 1-hexene hydrogenation, where at the end of the catalytic reaction, all metal remains in the aqueous phase indicating no leaching of the ruthenium during the reaction as was proved by atomic absorption experiments.