o-Phenylene-bridged or substituted
o-phenylene-bridged di- or trimethylcyclopentadienyl/carboxamideligands 2-(RMe
2C
5H
2)-4,6-R'
2C
6H
2NHC(O)
tBu (R = Me or H; R' = Me, H, or F) are prepared. WhenR' is methyl or H, unbridged trichlorotitanium complexes containing a chloroimine unit as a pendantgroup, 2-[(
5-RMe
2C
5H)TiCl
3]-4,6-R'
2C
6H
2N=C(Cl)
tBu (
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 ofTi(NMe
2)
4 and SiCl
4 to the ligands. The same treatment to the ligands where R' = F affords oxygen-coordinated bridged complexes [2-(
5-RMe
2C
5H)-4,6-F
2C
6H
2N=C(O)
tBu-
O]TiCl
2 (
11, R = H;
12, R= Me). The desired nitrogen-coordinated bridged complexes [2-(
5-RMe
2C
5H)C
6H
4NC(O)
tBu-
2N,
O]TiMe
2 (
13, R = H;
14, R = Me) are obtained by reacting the corresponding dilithium compound withMe
2TiCl
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 ×10
6 g/molTi·h at 13 bar ethylene). Trimethylcyclopentadienyl complexes show higher activity than thedimethylcyclopentadienyl analogues, and the activities of
12 and
14 reach ~65 × 10
6g/molTi·h. Complex
12 is excellent in incorporating 1-octene.