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

Reaction of bis(amide) sodium Na2[(1R,2R)-(−)-1,2-(NSiMe3)2-C6H10] (Na2[L1]) with Ti(OiPr)2Cl2 in different conditions gave mixed-ligand complexes [Ti(OiPr)Cl][L1] (1) or [Ti(OiPr)2Cl]2[L1] (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[L2]) or rarely linked bis(amidinate) ligand Li2[(1R,2R)-(−)-1,2-{NC(Ph)N(SiMe3)}2-C6H10](Li2[L3]) with ZrCl4 yielded the unbridged and bridged bis(amidinate) complexes ZrCl2[L2]2 (3) and [ZrCl2(THF)][L3] (4), respectively; Moreover, the reaction of (1R,2R)-(−)-1-Li[NC(Ph)N(SiMe3)]-2-Li(NSiMe3)C6H10(Li2[L2]) with Ti(OiPr)2Cl2 gave a new type of tridentate amido-amidinate product [Ti(OiPr)2][L2] (6), which is a distinct model compared to [Ti(OiPr)2Cl][L2] (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.