Synthesis, structures and polymerization catalytic properties of germyl-bridged bis(cyclopentadienyl) metallocenes

Abstract The ansa-metallocene complexes Me 2 Ge(η 5 -C 5 Me 4 ) 2 MCl 2 [M=Ti ( 1 ), Zr ( 2 )], Me 2 Ge(η 5 -C 5 H 3 Bu- t ) 2 ZrCl 2 ( 3 ) and Me 2 Ge(η 5 -C 5 H 4 )(η 5 -C 5 H 3 R)ZrCl 2 [R=Me ( 4 ), t -Bu ( 5 )] were prepared by the reaction of the corresponding ligands with n -BuLi and MCl 4 ·2THF, respectively. The molecular structures of 1 and 2 have been determined by the X-ray diffraction method. Complexes 2 – 5 in combination with MAO were studied as catalysts for ethylene polymerization and all the germyl-bridged zirconocene catalysts show high activities at relative high temperatures. This indicates that the germyl-bridged zirconocene systems show thermally stable catalyst systems for polymerization of ethylene.