Polyolefins like polyethylene and polypropylene are produced on a million ton scale and comprise a large portion of commercial polymeric materials. Their widespread application is based on high cost efficiency (cheap monomer and highly active catalysts) and the accessibility of different polyolefin grades from the same monomer (i.e. HDPE vs. UHMWPE) by simply changing the catalyst. Despite this success, the development of novel transition metal olefin polymerization catalysts is still of great interest. Late transition metals, due to their higher functional group tolerance, are able to produce functionalized polyolefins via direct copolymerization of polar vinyl monomers and non-polar olefins. Ruthenium has been used for a variety of catalytic reactions involving olefins (i.e. hydrogenations, metathesis) and showed excellent functional group tolerance, making it a seemingly promising candidate. However, Ru based olefin insertion polymerization catalyst are scarce, but our lab has recently demonstrated ethylene polymerization by an active Ru center. Here, the synthesis, characterization, and ethylene polymerization behavior of novel mononuclear Ru(OPO)(PPh3)(L) (OPO = bisanionic phosphine ligand, L = PPh3 or MeCN) complexes will be disclosed. The Ru(II) precursors were activated with solid methylaluminoxane at elevated temperatures to give linear (< 10 Me / 1000C), semicrystalline (Tm = 120 � 135�C) polyethylene with one of the highest reported activity for Ru based catalysts. Several novel electronic and steric ligand variants were prepared and it was found that the polymerization activity increased with the electron withdrawing character of the ligand. Furthermore, copolymerization reactions of ethylene with a-olefins and polar monomers were also investigated.

Ruthenium complexes for olefin insertion polymerization

247th National Meeting (2014)

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