New bifunctional chelating phosphine ligands for immobilization of metal complexes on oxidic supports

The immobilization of transition metal complexes by bifunctional phosphines containing ethoxysilane groups is of widespread interest. Especially desir able are chelating phosphines, since they can reduce leaching of the metal complexes. Easy syntheses of the bifunctional chelating ethoxysilane phosph ines Ph2PCH2CH[OSi(OEt)(3)]CH2PPh2, and Ph2P(CH2)(x)P- Ph(CH2)(y)Si(OEt)(3) (x = 2, 3: y = 2, 3), and the nickel derivative (CO)(2)Ni[Ph2P(CH2)(2)PPh( CH2)(2)Si(OEt)(3)] are reported. The ethoxysilane groups present convenient handles for immobilization on oxidic supports.