Synthesis and Characterization of Palladium(II) and Platinum(II) Complexes Containing Water-Soluble Hybrid Phosphine-Phosphonate Ligands

Water-soluble phosphonate-functionalized triaryl phosphine ligands Na(2)Ph(2)P(4-C(6)H(4)PO(3))].1.5H(2)O (4a), Na(2)Ph(2)P(3-C(6)H(4)PO(3))].2H(2)O (4b), and Na(2)Ph(2)P(2-C(6)H(4)PO(3))].2H(2)O (4c), were prepared in 54-56% yields by the transesterification and hydrolysis of the appropriate phosphonic acid diethyl ester precursors. The solubilities of 4a-c in water are compared and the spectroscopic properties studied in detail. The crystal structure of Na(2)Ph(2)P(4-C(6)H(4)PO(3))(H(2)O)(3)(CH(3)OH)].CH(3)OH (monoclinic, P2(1)/n, a = 6.4457(8) ?, b = 8.1226(8) ?, c = 46.351(3) ?, beta = 92.902(8) degrees, Z = 4) shows a dimeric association via two bridging water molecules and four sodium ions. Reaction of 4a with PtCl(2)(PPh(3))(2) in a biphasic H(2)O/CH(2)Cl(2) mixture gives cis- and trans-Na(4)PtCl(2){Ph(2)P(4-C(6)H(4)PO(3))}(2)]. 3H(2)O. Palladium dichloride and 4a in H(2)O/benzene catalyzes the carbonylation of benzyl chloride to give phenylacetic acid (91%).