Linked benzylamido-cyclopentadienyl ligands: Synthesis and characterization of alkyl titanium complexes

Article abstract of DOI:10.1002/cber.19971300211

Titanium complexes of the general type Ti(η⁵:η¹-C₅H₄Si-Me ₂NCH₂C₆H₃X₂-2,5)Cl ₂ (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-C₅H₄SiMe ₂NCH₂C₆H₃F₂-2,5)Cl ₂ revealed a conformation in the solid state in which the aryl ring is turned away from the metal center. Ti(η⁵:η¹-C₅H₄Si-Me ₂NCH₂C₆H₅)Cl₂ can be alkylated with a variety of reagents to form extremely sensitive complexes of the type Ti(η⁵:η¹-C₅H₄SiMe ₂NCH₂C₆H₅)R₂ (R = Me, CH₂C₆H₅, CH₂SiMe₃, CH₂CMe₂C₆H₅). Reaction of Li₂[C₅Me₄Si-Me₂NCH₂C ₆H₅] with TiCl₃(THF)₃ gave Ti(η⁵:η¹-C₅Me₄Si-Me ₂NCH₂C₆H₅)Cl₂, which can also be alkylated to form dialkyl complexes of the type Ti(η⁵:η¹-C₅Me₄Si-Me ₂NCH₂C₆H₅)R₂ (R = Me, CH₂C₆H₅, CH₂SiMe₃, C₆H₅). A single-crystal X-ray structural analysis of Ti(η⁵:η¹-C₅Me₄Si-Me ₂NCH₂C₆H₅)(CH₂C ₆H₅)₂ suggests the presence of α-agostic bonding of one of the titanium-bound CH₂C₆H₅ groups to the titanium center. VCH Vcrlagsgescllschaft mbH.