Monocyclopentadienyl and ansa-Monocyclopentadienylalkoxo Complexes of Titanium Containing the 2,2‘-Methylenebis(6-tert-butyl-4-methylphenoxo) Ligand. Synthesis, Characterization, and Polymerization Catalyst Behavior. Molecular Structure of Ti(η5-C5H5)(η2-MBMP)Cl, Ti(η5-C5Me5)(η2-MBMP)Cl, and Ti(η5-C5H4SiMe2-η1-MBMP)Cl2
摘要:
The dialkoxo titanium complexes TiCp'(eta(2)-MBMP)Cl [Cp' = eta(5)-C5H5 (1); eta(5)-C5Me5 (2)] have been prepared in good yields by reaction of Li-2(MBMP) with the corresponding monocyclo-pentadienyltrichloro titanium derivative. In a similar reaction the addition of 1 equiv of Li-2(MBMP) to Ti(eta(5)-C5H4SiMe2Cl)Cl-3 generates the analogous titanium compound Ti(eta(5)-C5H4SiMe2 Cl)(eta(2)-MBMP)Cl (3), while the ansa-cyclopentadienylalkoxo complex Ti(eta(5)-C5H4-SiMe2-eta(1)-MBMP)Cl-2 (4) is formed when MBMPH2 is treated with Ti(eta(5)-C5H4SiMe2Cl)Cl-3 in the presence of NEt3 in 1: 1: 2 molar ratio. Compounds 1, 2 and 4 have been characterized by single-crystal X-ray crystallography. DFT calculations were performed in order to elucidate the energies and geometries for these compounds. Upon addition of methylaluminoxane (MAO), the bisphenoxo complexes are active in the polymerization of alpha-olefins.