A synthetic route is reported for the water soluble complex RuCl (h 5-C 5 H 5)(TPPMS) 2 (1),(TPPMS=(C 6 H 5) 2 P (C 6 H 4-m-SO 3 Na) and characterized by UV-Vis, FTIR, 1 H, 13 C NMR and GC-MS. Complex 1 is a good catalytic precursor in biphasic media (toluene/water) for 1-hexene hydrogenation under moderate reaction conditions (eg 500 psi H 2, 100° C) giving good yields of n-hexane, and smaller amounts of cis-2-hexene and trans-2-hexene. Other organic substrates (cinnamaldehyde, crotonaldehyde, cyclohexene