SYNTHESIS AND STRUCTURES OF NEUTRAL AND CATIONIC RAC-(ETHYLENEBIS(TETRAHYDROINDENYL))ZIRCONIUM(IV) BENZYL COMPLEXES

Reaction of rac-(ethylenebis(tetrahydroindenyl))ZrCl2 (1) with 2 equiv of K[CH2Ph] produces the dibenzyl complex (ethylenebis(tetrahydroindenyl))Zr(CH2Ph)2 (2). Reaction of 2 with [(C5H4Me)2Fe][BPh4] yields the cationic complex [(ethylenebis(tetrahydroindenyl))Zr(CH2Ph)(THF)][BPh4] (3). In CH3CN solvent, 3 undergoes ligand substitution to yield [(ethylenebis(tetrahydroindenyl))Zr(η2-CH2Ph)(CH3CN)][BPh4] (4). The structures of 2 and 4 have been determined by X-ray diffraction. Complex 2 crystallizes in space group Pbcn with a = 10.008 (3) Å, b = 14.895 (4) Å, c = 17.532 (6) Å,V= 2613.5 (2.4) Å3, and Z = 4. The benzyl ligands are undistorted and are rotated to conformations that minimize steric interactions with the (CH2)4 rings of the (ethylenebis(tetrahydroindenyl))Zr framework. Complex 4 crystallizes in space group P1 with a = 12.300 (2) Å, b = 12.493 (2) Å, c = 16.633 (3) Å, α = 84.61 (1)°, β = 71.18 (1)°, γ = 69.42 (1)°, V = 2264.1 (9) Å3, and Z = 2. The CH2Ph ligand of 4 is bonded in a η2 mode with a weak Zr-Ph interaction. The (ethylenebis(tetrahydroindenyl)Zr framework of 4 is distorted relative to that of 2 to minimize steric interactions between a (CH2)4 ring and the η2-CH2Ph ligand. © 1990, American Chemical Society. All rights reserved.