Synthesis of a new family of water-soluble tertiary phosphine ligands and of their rhodium(I) complexes; olefin hydrogenation in aqueous and biphasic media

Article abstract of DOI:10.1016/0022-328X(91)80253-G

The series of phosphonium phosphines (Ph2P(CH2)nPMe3>X (n = 2, 3, 6, 10; N = NO3^-, Cl^-, PF6^-), henceforth II-, III-, VI- and X-phosphos respectively, have been prepared and characterized.The ligands react with 2 (NBD = norbornadiene) to form the complexes X, one of which, PF6, has been characterized crystallographically.The 1:1 complexes X react with a second equivalent of ligand to form the complexes X, which form very active olefin hydrogenation catalysts in aqueous and aqueous-organic biphasic systems.The effect of chain length on activity is very significant, the complex of VI-phosphos forming the most active catalyst.