Supported Constrained-Geometry Catalysts on Cross-Linked (Aminomethyl)polystyrene: Studies of Ethylene and 1-Octene Polymerizations

Abstract

The reaction of TiCl4 with (chlorodimethylsilyl)(trimethylsilyl)cyclopentadiene results in the chemoselective elimination of Me3SiCl and cleanly affords ((chlorodimethylsilyl)cyclopentadienyl)titanium trichloride (2). Likewise, the reaction of TiCl4 with (chlorodimethylsilyl)(trimethylsilyl)tetramethylcyclopentadiene (6) also results in the chemoselective elimination of Me3SiCl and cleanly affords ((chlorodimethylsilyl)tetramethylcyclopentadienyl)titanium trichloride (7). This observation is in sharp contrast to the reaction of 6 with ZrCl4, which results in the chemoselective elimination of Me3SiCl but affords a mixture of half-sandwich and zirconocene complexes. Support of complex 2 or 7 on (aminomethyl)polystyrene (AMPS, 1% cross-linking, 1.3 wt % N, 0.928 mmol of N/g of support), where the mole ratio of amine content of the support to precursor catalysts was selected to be 3:1, leads to the assembly of the constrained-geometry catalyst (CGCs) 8 or 9, respectively. From the 29Si NMR, the presence of a ...