Titanium and Zirconium Complexes with the New Ancillary Diamido Ligand N,N‘-Bis(trimethylsilyl)amidobenzylamido(2−):  Syntheses, Structures, and α-Olefin Polymerization Activities

Using the disymmetric N,N ‘ -bis(trimethylsilyl)aminobenzylamine (H 2 MABA; 1 ) ligand, the new group 4 metal complexes (MABA)TiCl 2 ( 2 ), (MABA)TiMe 2 ( 3 ), (MABA)Ti(CH 2 Ph) 2 ( 4 ), (MABA)ZrCl 2 ( 5 ), and (MABA) 2 Zr ( 6 ) were prepared. X-ray crystal structures of 2, 4, and 6 were determined. The crystal structure of 2 suggests that an agostic interaction between the titanium metal center and benzylic protons exists in the solid state. However, the agostic interaction is not sustained in solution, as indicated by NMR spectroscopy. Complexes 2 and 5, activated by MMAO, and 4, activated by B(C 6 F 5 ) 3, have moderate catalytic activities for the polymerization of α-olefins.