Titanium and Zirconium Amido Complexes Ligated by 2,2-Di(3-methylindolyl)methanes: Synthesis, Characterization, and Ethylene Polymerization Activity

2,2ʹ-Di(3-methylindolyl)methanes (L2H2) are introduced as dianionic, bidentate ligands of reduced -donating ability. Four complexes of the type L2Ti (NEt2)2 and L2Zr(NEt2)2(THF) have been synthesized and characterized by elemental analysis, NMR (1H, 13C) spectroscopy, and X-ray crystallography. Structural data confirm the reduced (pi)-donating ability of the (eta)1-indolyl moiety compared to that of diethylamido. Preliminary catalytic activities of these group 4 complexes for the polymerization of ethylene are reported.