NEW LIGAND ENVIRONMENTS FOR SOLUBLE ZIEGLER-NATTA OLEFIN POLYMERIZATION CATALYST PRECURSORS - X-RAY STRUCTURES OF [(ETA(5)-C(5)ME(4)SI(ME(2))OCH2C4H7NH)ZRCL3] AND [(ETA(5)-C(5)ME(4)SIME(3))(2)ZR-2(CH3)(2)(MU-ETA(2)-C5H9NO)(2)]

Treatment of dimethyl(tetramethylcyclopentadienyl)chloro silane with S-(-)pyrrolidine methanol provided the O-silylated ligand (C(5)Me(4)H)SiMe(2)OCH(2)(C4H7NH), 1, (Cp*SiProH(2)) as 90% pure, thermally unstable oil in 65% yield. Reaction of 1 with Zr(NMe(2))(4) resulted in attachment of 1 to the zirconium center with elimination of HNMe(2), yielding (Cp*SiPro)Zr(NMe(2))(2), 2, as a viscous oil in high yield (95%). Compound 2 was converted to the trichloride derivative (Cp*SiProH)ZeCL(3), 3, in 75% yield by treatment with three equivalents of HCl.HNME(2): compound 3 is produced as a mixture of diastereomers; the major species was characterized by X-ray crystallography, revealing Cp*-O-N coordination mode for the Cp*SiProH ligand. (3: orthorhombic, space group P2(1)2(1)2(1), a = 10.000.(13), b = 12.7597(12), c = 16.2749(15) Angstrom, V = 2076.8(4) Angstrom(3), Z = 4, R = 0.043, Rw = 0.041.) Deprotonation of 3 (diastereomeric mixture) with LiN(SiMe(3))2 produced the dichloride (Cp*SiPro)ZrCl2, 4, in 71% yield. Alkylation of either 3 or 4 resulted in Si-O bond cleavage in the Cp*SiPro ligand and gave a dimeric complex 5 which was characterized by X-ray crystallography. (5: monoclinic, space group P2(1), a = 9.1285(10), b = 20.2197(22). c = 11.0214(14) Angstrom, beta = 90.38(7)degrees, V = 2034.2(4) Angstrom(3), Z = 2, R = 0.040, R(w) = 0.042.) Limited ethylene polymerization activity was observed for 3 and 4 in the presence of MAO co-catalyst.