Diverse coordination behaviors of the silyl-linked bis(amidinate) ligand [SiMe2{NC(Ph)N(Ph)}2]2− to zirconium center

Abstract The reactions between the silyl-linked bis(amidinate) ligand [SiMe 2 {NC(Ph)N(Ph)Li(thf) 2 } 2 ] and ZrCl 4 in different stoichiometric chemistry, 2:1, 1:1, and 1:2, were explored. The resulting zirconium compounds, 1 , 2, and 3 , showed different molecular structural features which were confirmed by X-ray crystallographic analysis. The metal center in 1 was located in a highly saturated coordination environment with four amidinate moieties. Compound 2 exhibited an unprecedented linked tris(amidinate) N–C–N–Si–N–C–N–Si–N–C–N skeleton formed after the intermolecular rearrangement. In compound 3 , a novel silyl-linked imino-amidinate ligand via the intramolecular rearrangement was involved. The mechanism for the formation of compounds 2 and 3 was proposed. Compound 2 was found to be a highly active catalyst for ethylene polymerization in the presence of methylalumoxane (MAO).