SOLVENT EFFECT FOR OXIDATIVE ADDITION OF HYDROGEN IN SOLVENTS FROM TOLUENE TO WATER - REACTION OF H-2 WITH TRANS-[IR(CO)CL(PPH(2)(C6H4SO3K-M))(2)]

A significant enhancement in the rate of oxidative addition of H-2 to square-planar iridium(II) complexes in water is observed; kinetic stud ies of the addition of H-2 to trans-[Ir(CO)Cl(PPh(3))(2)] in toluene a nd of H-2 to trans-[Ir-(CO)Cl{PPh(2)(C6H4SO3K-m)}(2)] in water show a factor of 45 increase in rate constant in water; this solvent effect i s shown to be general for the solvents toluene, chlorobenzene, N,N-dim ethylformamide, dimethyl sulfoxide and water, and has important ramifi cations for catalysis in water.