Synthesis, structures, and catalytic properties of dimeric constrained geometry diphenylcyclopentadienyl-phenoxyoxochlorotitanium(IV) complexes

Two dimeric diphenyl cyclopentadienylphenoxyoxochlorotitanium(IV) complexes {[η5;η1-2-(3,4-Ph2Cp)-4,6-di-tBu-C6H2O]TiCl}2O (3) and {[η5;η1-2-(3,4-Ph2Cp)-6-tBu-C6H3O]TiCl}2O (4) have been synthesized by hydrolysis of the monomeric 2-(3,4-diphenyl-cyclopentadienyl)-4,6-di-tert-butyl phenoxytitanium dichloride (1) and 2-(3,4-diphenyl-cyclopentadienyl)-6-tert-butyl phenoxytitanium dichloride (2). The molecular structure of 3 was characterized by spectroscopy and X-ray crystallography. Both of the complexes exhibited high catalytic activities for ethylene polymerization in the presence of Al(iBu)3 and Ph3+B(C6F5)4-.