Linked Benzylamido-Cyclopentadienyl Ligands: Synthesis and Characterization of Alkyl Titanium Complexes

Titanium complexes of the general type Ti(η5:η1-C5H4Si-Me2NCH2C6H3X2-2,5)Cl2 (XH, F), containing a linked benzylamido-cyclopentadienyl ligand, were prepared by reaction of Ti(η5-C5H4SiMe2Cl)Cl3 with lithium amide Li(NHCH2C6H3X2-2,5). A single-crystal X-ray structural analysis of Ti(η5: η1-C5H4SiME2NCH2C6H3F2-2,5)Cl2 revealed a conformation in the solid state in which the aryl ring is turned away from the metal center. Ti(η5:η1-C5H4SiMe2NCH2C6H5)Cl2 can be alkylated with a variety of reagents to form extremely sensitive complexes of the type Ti(η5-C5H4SiMe,2NCH2C6H5)R2 (RMe, CH2 C6H5, CH2SiME3, CH2CMe2C6H5). Reaction of Li2[C5Me4SiMe2NCH2C6H5] with TiCl3(THF)3 gave Ti(η5: η1-C5Me4SiMe2NCH2C6H5)Cl2, which can also be alkylated to form dialkyl complexes of the type Ti(η5:η1-C5Me4SiMe2NCH2C6H5)R2(RMe, CH2C6H5, CH2SiMe3, C6H5).A single-crystal X-ray structural analysis of Ti(η5:η1-C5Me4SiMe2NCH2C6H5)(CH2C6H5)2 suggests the presence of α-agostic bonding of one of the titanium-bound CH2C6H5 groups to the titanium center.