LINKED BENZYLAMIDO-CYCLOPENTADIENYL LIGANDS - SYNTHESIS AND CHARACTERIZATION OF ALKYL TITANIUM COMPLEXES

Titanium complexes of the general type (5):eta(1)-C5H4Si-Me(2)NCH(2)C( 6)H(3)X(2)-2,5)Cl-2 (X = H, F), containing a linked benzylamido-cyclop entadienyl ligand, were prepared by reaction of Ti(eta(5)-C(5)H(4)SiMe (2)Cl)Cl-3 with lithium amide Li(NHCH(2)C(6)H(3)X(2)-2,5). A single-cr ystal X-ray structural analysis of :eta(1)-C(5)H(4)SiMe(2)NCH(2)C(6)H( 3)F(2)-2,5)Cl-2 revealed a conformation in the solid state in which th e aryl ring is turned away from the metal center. Ti(eta(5):eta(1)-C5H 4Si-Me(2)NCH(2)C(6)H(5))Cl-2 can be alkylated with a variety of reagen ts to form extremely sensitive complexes of the type i(eta(5):eta(1)-C (5)H(4)SiMe(2)NCH(2)C(6)H(5))R(2) (R = Me, CH2C6H5, CH(2)SiMe(3), CH(2 )CMe(2)C(6)H(5)). Reaction of Li-2[C(5)Me(4)Si-Me(2)NCH(2)C(6)H(5)] wi th TiCl3(THF)(3) gave ta(5):eta(1)-C(5)Me(4)Si-Me(2)NCH(2)C(6)H(5))Cl- 2, which can also be alkylated to form dialkyl complexes of the type e ta(5):eta(1)-C(5)Me(4)Si-Me(2)NCH(2)C(6)H(5))R(2) (R = Me, CH2C6H5, CH (2)SiMe(3), C6H5). A single-crystal X-ray structural analysis of ta(1) -C(5)Me(4)Si-Me(2)NCH(2)C(6)H(5))(CH2C6H5)(2) suggests the presence of alpha-agostic bonding of one of the titanium-bound CH2C6H5 groups to the titanium center.