SYNTHESIS AND CHARACTERIZATION OF C-1-BRIDGED AND C-2-BRIDGED BIS(FLUORENYL) COMPLEXES OF ZIRCONIUM AND HAFNIUM AND THEIR APPLICATION IN CATALYTIC OLEFIN POLYMERIZATION

The addition of n-butyl lithium to bis-biphenylene propene (1) or 1,4- bis-biphenylene butadiene (2) followed by the reaction with zirconium tetrachloride or hafnium tetrachloride leads to C-1- or C-2-bridged bi s(fluorenyl) complexes of zirconium or hafnium containing substituents in the bridge. Complexes of the type (C13H8-C(H)Bu-C13H8)MCl2, (M = Z r (3), Hf (4)) are the first known examples of C-1-bridged bis(fluoren yl) complexes of a group 4 metal.