Zirconium complexes with the new ancillary diamido ligand 2,2′-ethylenebis(N,N′-(triisopropylsilyl)anilinido)2-:: Syntheses, structures, and living α-olefin polymerization activities

Using the new ancillary ligand 2,2'-ethylenebis(N,N'-(triisopropylsilyl)anilinido) ((EBTP)-P-i, 1), the zirconium complexes ((EBTP)-P-i)ZrCl2 (2) and ((EBTP)-P-i)-ZrMe2 (3) have been prepared. X-ray crystal structures and H-1 NMR spectra of 2 and 3 reveal that they both have a C-2-symmetric conformation. Complexes 2, activated by MAO, and 3, activated by either MAO or B(C6F5)(3) are good catalysts for the polymerization of terminal olefins. In. particular, the polymerization of 1-hexene catalyzed by 3/B(C6F5)(3) at low temperature is living.