Manganese Catalysts with Scorpionate Ligands for Olefin Polymerization

Abstract

The catalyst systems composed of hydrotris(pyrazolyl)borate (Tp) manganese and coactivators showed good activity for ethylene polymerization and ethylene−α-olefin copolymerization. The activity of [MnCl(Tp)]/Al(i-Bu)3/[Ph3C][B(C6F5)4] for ethylene/1-butene copolymerizations goes up to 1.6 × 107 g mol(cat)-1 h-1, giving ethylene−1-butene copolymer with a narrow molecular weight distribution (Mw/Mn = 1.8) and a high melting point (120 °C). This system is also active toward propylene and gives isotactic polypropylene with a triad mm fraction of 0.905.