Asymmetric binuclear metallocene complexes and their application for olefin polymerization

Asymmetric double silylene‐bridged binuclear complexes [(η 5 ‐RC 5 H 4 )MCl 2 ] 2 [μ, μ‐(SiMe 2 ) 2 (η 5 ‐t‐BuC 5 H 2 )(η 5 ‐C 5 H 3 )][R = H, M = Ti (1); R = Me, M = Ti (2); R = allyl, M = Ti(3); R = H, M = Zr (4); R = allyl, M= Zr (6)]; and [(η 5 ‐C 5 H 5 )TiCl 2 ] 2 [μ, μ‐(SiMe 2 ) 2 (η 5 ‐Me 3 SiC 5 H 2 )(η 5 ‐C 5 H 3 )] (5) were synthesized by the reaction of (η 5 ‐RC 5 H 4 ) TiCl 3 or (η 5 ‐RC 5 H 4 )ZrCl 3 ·DME (R = H, allyl) with [μ, μ‐ (SiMe 2 ) 2 (η 5 ‐t‐BuC 5 H 2 )(η 5 ‐C 5 H 3 )] Li 2 or [μ, μ‐(SiMe 2 ) 2 (η 5 ‐Me 3 Si C 5 H 2 )(η 5 ‐C 5 H 3 )]Li 2 in THF, and they were all well characterized by 1 H NMR, MS, IR, and EA. When activated with methylaluminoxane (MAO), they are efficient catalysts for the polymerization of ethylene (Complex 4, 5.99 × 10 5 g‐PE/mol·Zr·h) and the polymer with multipeak broaden molecular weight distribution (PD = M w/ M n) was obtained (polymer sample gained by complex 3, PD = 25.03). The copolymerization results indicate that 1‐hexene could incorporate into the growing PE chain with these complexes in the presence of MAO (Complex 4, 1.07 × 10 6 g‐PE/mol·Zr·h; 1‐hexene content, 1.57% mol). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2891–2900, 2013