Synthesis and characterization of organozirconium complexes bearing a new trianionic multidentate cyclopentadienyl ligand by use of amine elimination

The new multidentate ligand o-(NH(C6H5)(N′H(Si(CH3)2(C5(CH3)4H))C6H4 (1), was synthesized by the reaction of (C5(CH3)4(H)Si(CH3)2Cl) with o-C6H4(NH2)(N′HPh) in the presence of NEt3. The ligand was bound to Zr using the amine elimination method through the reaction of 1 with Zr(N(CH3)2)4. Because of the incomplete removal of HCl generated in the synthesis of 1, two complexes were isolated and characterized from the reaction of 1 with Zr(N(CH3)2)4, o-C6H4{N(C6H5)N′[Si(CH3)2(C5(CH3)4)]}Zr(N(CH3)2)(NH(CH3)2) (2) and o-C6H4{N(C6H5)N′[Si(CH3)2(C5(CH3)4)]}Zr(Cl)(NH(CH3)2)2 (3). The structures of both 2 and 3 were confirmed by X-ray crystallography. Crystals of 2 are triclinic, space group P1̄, with a=10.9864(1), b=11.8841(2), c=12.3633(1) Å, and Z=2. Compound 2 has a square-pyramidal geometry with the NMe2 group occupying the apical position. Crystals of 3 are monoclinic, space group P21/c, with a=12.1925(2), b=18.9677(4), c=12.2218(2) Å, and Z=4. Complex 3 has a distorted octahedral geometry with the cyclopentadienyl and the amido groups of the chelating ligand occupying pseudo-meridional positions.