Solid-Supported Single-Component Pd(II) Catalysts for Polar Monomer Insertion Copolymerization

Heterogenized representatives of
neutral phosphine sulfonato Pd­(II)
complexes for polar monomer insertion polymerization were prepared
by two different approaches. [{κ2-(P,O)-(2-anisyl)2PC6H4SO2O}­Pd­(Me)­L] (L
= pyr, dmso, or Cl) complexes were physisorbed on inorganic substrates,
namely, clay or silica. In addition, new phosphine sulfonato complexes
bearing hydroxyl linker groups at the nonchelating P-aryl moiety were prepared. These complexes were covalently tethered
to cross-linked polystyrene. All immobilized palladium complexes are
active in ethylene polymerization and ethylene/MA copolymerization
without any additional cocatalyst. In addition, separation from the
polymer solution formed and reutilization for another polymerization
were demonstrated for polystyrene-bound complexes.