Syntheses and models for stereospecific metallocenes

Abstract

Abstract Stereospecific, bridged [LL']M(R) + catalysts (L, L' = substituted‐cp, ind, or flu; R = hydrocarbyl) have been prepared by three new synthetic procedures. Propylene polymerizations with our new catalyst synthetic reagents, tris(pentafluorophenyl)boron (F15), magnesium dichloride, and trityl tetrakis(pentafluorophenyl)borate (trityl‐F20) are compared with results obtained with the N, N‐dimethyl‐anilinium‐F20 salt and with methylaluminoxane (MAO). Trimethylaluminium (TMA) or triethylaluminium(TEAL) scavenged poisons in the MAO free polymerizations. The site‐control mechanism is discussed.