Polymerizable group 4 ansa-cyclopentadienyl-amido catalysts for the copolymerization of ethylene with 1-octene

Abstract A styrene unit has been successfully incorporated into the half metallocene constrained-geometry framework as [( η 5 -C 5 Me 4 )SiMe 2 ( η 1 -NC 6 H 4 CH CH 2 )]MX 2 ( M  = Ti, X  = NMe 2 , 6a ; M  = Zr, X  = NMe 2 , 6b ; M  = Ti, X  = Cl, 7a ; M  = Zr, X  = Cl, 7b ). These complexes have been characterized with 1 H NMR, 13 C NMR spectroscopy together with single crystal X-ray diffraction studies of 6a and 6b . A polystyrene-immobilized constrained-geometry catalyst 8 was formed by the radical copolymerization of 7a with styrene using AIBN as the initiator. The complexes 6a , 6b , 7a and 8 gave active homogeneous catalysts for the copolymerization of ethylene with 1-octene when treated with excess methylalumoxane (MAO). The polymerization results showed that 7a was highly active and effective for the incorporation of comonomer 1-octene whereas the zirconium complex 6b and the immobilized catalyst 8 yield low activities and low incorporations of 1-octene in the products with broad molecular weight distributions.