Phenylene-Bridged Cp/Carboxamide Ligands for Titanium Complexes of Various Binding Modes and Their Ethylene/1-Octene Copolymerization
作者:Ui Gab Joung、Chun Ji Wu、Sang Hoon Lee、Choong Hoon Lee、Eun Jung Lee、Won-Sik Han、Sang Ook Kang、Bun Yeoul Lee
DOI:10.1021/om060604x
日期:2006.10.1
o-Phenylene-bridged or substituted o-phenylene-bridged di- or trimethylcyclopentadienyl/carboxamide ligands 2-(RMe2C5H2)-4,6-R ' 2C6H2NHC(O)Bu-t (R = Me or H; R ') Me, H, or F) are prepared. When R ' is methyl or H, unbridged trichlorotitanium complexes containing a chloroimine unit as a pendant group, 2-[(eta(5)-RMe2C5H)TiCl3]-4,6-R ' 2C6H2N=C(Cl)Bu-t (7, R = H, R ' = H; 8, R = Me, R ' = H; 9, R = H, R ') Me; 10, R) Me, R ') Me), are unexpectedly afforded through the successive addition of Ti(NMe2)(4) and SiCl4 to the ligands. The same treatment to the ligands where R ' = F affords oxygen-coordinated bridged complexes [2-(eta(5)-RMe2C5H)-4,6-F2C6H2N=C(O)Bu-t-kappa O]TiCl2 (11, R = H; 12, R = Me). The desired nitrogen-coordinated bridged complexes [2-(eta(5)-RMe2C5H)C6H4NC(O)Bu-t-kappa N-2,O]TiMe2 (13, R) H; 14, R = Me) are obtained by reacting the corresponding dilithium compound with Me2TiCl2. The binding modes of 7, 8, 9, 11, and 14 are confirmed by X-ray crystallography. Trichlorotitanium complex 8 shows high activity in ethylene/1-octene copolymerization (activity, 100 x 10(6) g/molTi center dot h at 13 bar ethylene). Trimethylcyclopentadienyl complexes show higher activity than the dimethylcyclopentadienyl analogues, and the activities of 12 and 14 reach similar to 65 x 10(6)g/molTi(.)h. Complex 12 is excellent in incorporating 1-octene.