Synthesis and structural studies of some titanium and zirconium complexes with chiral bis(amide), amidinate or bis(amidinate) ligands

Reaction of bis(amide) sodium Na-2[(1R,2R)-(-)-1,2-(NSiMe3)(2)-C6H10] (Na-2[L-1]) with Ti(OiPr)(2)Cl-2 in different conditions gave mixed-ligand complexes [Ti(OiPr)G][L-1] (1) or [Ti(OiPr)(2)Cl](2)[L-1] (2); 2 is a dinuclear titanium example in which Ti atoms are bridged by nitrogen and oxygen atoms simultaneously forming a distorted rhombic core. Reaction of the amine-amidinate ligand (1R,2R)-(-)-1-Li[NC(Ph)N(SiMe3)]-2-(NHSiMe3)-C6H10(Li[L-2]) or rarely linked bis(amidinate) ligand Li-2[(1R,2R)-(-)-1,2-{NC(Ph)N(SiMe3)}(2)-C6H10](Li-2[L-3]) with ZrCl4 yielded the unbridged and bridged bis(amidinate) complexes ZrCl2[L-2](2) (3) and [ZrCl2(THF)][L-3] (4), respectively; Moreover, the reaction of (1R,2R)-(-)-1-Li[NC(Ph)N(SiMe3)]-2-Li(NSiMe3)C6H10(Li-2[L-2]) with Ti(OiPr)(2)Cl-2 gave a new type of tridentate amido-amidinate product [Ti(OiPr)(2)][L-2] (6), which is a distinct model compared to [Ti(OiPr)(2)Cl][L-2] (5) yielded from Li[L2]. All the products have been characterized by X-ray crystallography and the structural studies are presented detailedly comparing with relevant compounds. (c) 2006 Elsevier B.V. All rights reserved.