Phenylene-bridged Cp/carboxamide ligands for titanium complexes of various binding modes and their ethylene/1-octene copolymerization

o-Phenylene-bridged or substituted o-phenylene-bridged di- or trimethylcyclopentadienyl/carboxamide ligands 2-(RMe 2 C 5 H 2 )-4,6-R' 2 C 6 H 2 NHC(O) t Bu (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-[(η 5 -RMe 2 C 5 H)TiCl 3 ]-4,6-R' 2 C 6 H 2 N=C(Cl) t Bu (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(NMe 2 ) 4 and SiCl 4 to the ligands. The same treatment to the ligands where R' = F affords oxygen-coordinated bridged complexes [2-(η 5 -RMe 2 C 5 H)-4,6-F 2 C 6 H 2 N=C(O) t Bu-κO]TiCl 2 (11, R = H; 12, R = Me). The desired nitrogen-coordinated bridged complexes [2-(η 5 -RMe 2 C 5 H)C 6 H 4 NC(O) t Bu-κ 2 N,O]-TiMe 2 (13, R = H; 14, R = Me) are obtained by reacting the corresponding dilithium compound with Me 2 TiCl 2 . 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·h at 13 bar ethylene). Trimethylcyclopentadienyl complexes show higher activity than the dimethylcyclopentadienyl analogues, and the activities of 12 and 14 reach ∼65 x 10 6 g/molTi·h. Complex 12 is excellent in incorporating 1-octene.