NEW MONONUCLEAR AND BINUCLEAR ANSA-METALLOCENES OF ZIRCONIUM AND HAFNIUM AS CATALYSTS FOR THE POLYMERIZATION OF ETHENE AND PROPENE

The new ansa-metallocenes [M{Me(2)C(eta-C5H4)(eta(2)-C9H6)}(eta-C5H5)C l] [M = Zr (crystal structure) or, Hf], [M{(CH2)(5)C(eta-C5H4)(eta(2)- C9H6)}(eta-C5H5)Cl]. 0.5C(6)H(5)Me [M = Zr (crystal structure) or Hf], [Zr{Me(2)C(eta-C5H4)(eta(3)-C13H8)}(eta-C5H5)Cl] (crystal structure), [M{Me(2)C(eta-C5H4)(2)}(eta-C5H5)Cl][M = Zr or Hf (crystal structures )], 2)(eta-C5H5)M{C5H4(CMe(2))C9H6)}M(eta-C5H5)X(2)}] (X = Cl, M, M* = Zr, Zr, Hf, Hf; Zr, Hf; or Hf, Zr, X = Me, M, M = Zr, Zr; Zr, Hf; H f, Zr; or Hf, Hf), a-C5H5)Zr{C5H4(CMe(2))C9H6}-Zr(eta-C(5)Me(5))Cl-2] [{M(C(5)H(4)CMe(2)(C9H7)}(eta-C5H5)Cl-2] (M = Zr or Hf) and [Zr{C(5)H( 4)CMe(2)(C9H7}-(eta-C5H5)Me(2)] have been prepared and characterised. The activity of the metallocenes as cocatalysts for the polymerisation of ethene and propene has been evaluated.