SYNTHESIS AND CATALYTIC PROPERTIES OF ANSA-BINUCLEAR METALLOCENES OF THE GROUP-IV TRANSITION-METALS

The new ansa-bridged mono- and bi-nuclear Group IV metallocenes, {Zr[X (eta-C5H4)(2)](eta-C5H5)Cl} (where, X = SiMe(2) (1), CMe(2)CMe(2) (2)) , [mu-eta-C5H4-(SiMe(2))-eta-C5H4][(eta-C5H5)HfCl2]} (3). e(2)CH(2)CH( 2)SiMe(2))-eta-C5H4][(eta-C5H5)ZrCl2]} (4), [mu-eta-C5H4-(SiMe(2))-eta -C9H6][(eta-C5H5)ZrCl2]} (5), [mu-eta-C9H6-(SiMe(2))-eta-C9H6][(eta-C5 H5)ZrCl2]} (6), u-eta-C5H4-(SiMe(2))-eta-C5H4][(eta-C5H5)MCl(2)]}, M = Hf (7) or Ti (8), ta-C5H4-(SiMe(2))-eta-C5H4][(eta-C(5)Me(5))TiCl2]} (9) and C5H5)ZrCl2][mu-eta-C5H4(SiMe(2))-eta-C5H4][TiCl3]} (10) an des cribed. These compounds in the presence of methylaluminoxane are catal ysts for the polymerisation of ethene and propene.