Bis(triisopropylsilyl)-<i>o</i>-phenylenediamido Complexes of Titanium and Zirconium:  Investigation of a New Ancillary Ligand

From the dilithio reagent o-C6H4(NLiSiiPr3)2 (2), the new complexes [o-C6H4(NSiiPr3)2]2Zr (3), [o-C6H4(NSiiPr3)2]Zr(OtBu)2 (4), [o-C6H4(NSiiPr3)2]TiCl2 (5), and [o-C6H4(NSiiPr3)2]TiMe2 (6) have been prepared. X-ray crystallographic and variable-temperature NMR studies characterize these complexes as possessing η4-C6H4(NSiiPr3)2 ligands (bonded to the metal via two carbon atoms in the phenylene group), which undergo a η4−η2 fluxional process in solution.