NMR study of branched polyethylenes obtained with combined Fe and Zr catalysts

The products obtained with the system {[(ArN=C(Me))(2)C5H3N]FeCl2}/MAO (Ar = 2-C6H4-(Et)) (1) and the ones obtained by the use of 1 in conjunction with Me(2)SiInd(2)ZrCl(2)/MAO (2) or EtInd(2)-ZrCl2/MAO (3) were completely characterized by H-1 NMR and C-13 NMR. Catalyst 1 gives mainly linear alpha-olefins of molecular weights close to 2000 g/mol and a low amount of alkanes. The use of 1 with 2 or 3 using only ethylene as monomer gives branched polyethylene with ethyl, butyl, and mainly long branches. Some amount of unreacted alpha-olefin was also found in some cases, especially in reactions where a high ratio Fe to Zr was used.