Self‐induced short chain branching in homopolymers and 1‐hexene copolymers of ethylene produced with amido functionalized ansa half‐sandwich complexes as catalysts

Abstract Amido ansa 3‐substituted indenyl complex precursors can be activated with methylaluminoxane and used for prepolymerization with ethylene to give a heterogeneous catalyst for olefin polymerization. Homo polymerization of ethylene with 1‐(3‐pent‐4‐enylindenylidene) dimethylsilyl'butylamidotitaniumdichloride (1), 1‐(3‐hex‐5‐enylindenylidene)dimethylsilyl'butylamidotitanium‐dichloride (2), and 1‐(3‐pent‐4‐enylindenylidene) (oct‐7‐enyl)methylsilyl'butylamidotitaniumdichloride (3) produces polyethylenes that contain ethyl branches. The ethyl branching in the polymers made with complexes 1 and 2 is barely above the 13C NMR detection limit, but the level observed in the polymer made with complex 3 is 17 times greater. Copolymerization of ethylene and 1‐hexene using prepolymerized 3 yields copolymers containing both ethyl and butyl branches. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 734–739, 2006