A synthetic route is reported for the water soluble complex RuCl(eta(5)-C5H5)(TPPMS)(2) (1), (TPPMS = (C6H5)(2)P(C6H4-m-SO3Na) and characterized by UV-Vis, FTIR, H-1, C-13 NMR and GC-MS. Complex 1 is a good catalytic precursor in biphasic media (toluene/ water) for 1-hexene hydrogenation under moderate reaction conditions (e.g. 500 psi H-2, 100degreesC) giving good yields of n-hexane, and smaller amounts of cis-2-hexene and trans-2-hexene. Other organic substrates (cinnamaldehyde, crotonaldehyde, cyclohexene, acetone and butylaldehyde) are hydrogenated.