Synthesis, structure and catalytic properties of new half-titanocene complexes bearing substituted cyclopentadienyl and aryloxide ligands

New cyclopentadienyltitanium aryloxide complexes, 1-phenyl-2,3,4,5-Me4CpTi(O-2,6-Pr-i(2)-4-Bu-n-C6H2)Cl-2 (1) and [4,4-biphenyl-(2,3,4,5-Me4Cp)(2)][Ti(O-2,6-Pr-i(2)-4-Bu-n-C6H2)Cl-2](2) (2), have been prepared by treatment of cyclopentadienyltitanium trichloride complexes [PhMe4CpTiCl3 and 4,4-biphenyl-(Me4CpTiCl3)(2)] with 1 or 2 equiv of lithium salt of 2,6-di-isopropyl-4-butylphenol. Complexes 1 and 2 have been characterized by elemental analysis, H-1 and C-13 NMR spectroscopy. The molecular structure of 1 has been determined by single-crystal X-ray diffraction. Upon activation with (Bu3Al)-Bu-i and Ph3CB(C6F5)(4), 1 and 2 both exhibit good catalytic activity for ethylene polymerization, producing polyethylene with moderate molecular weight and melting point.