Addition of 1-(trimethylsilyl)heptamethylindene (C9Me7SiMe3) to a suspension of the anhydrous halides MCl4 (M = Ti, Zr, and Hf) in THF gives the half-sandwich complexes M(η5-C9Me7)Cl3 (M = Ti, Zr, and Hf) in good yield. Ti(η5-C9Me7)2Cl3 crystallizes in the centrosymmetric orthorhombic space group Pbca with a = 16.875(4) Å, b = 14.706(3) Å, c = 13.781(3) Å, V = 3420 Å3, Z = 8, R = 0.047, and Rw = 0.049. The Ti‒C distances range from 2.352(4) to 2.400(4) Å with a mean value of 2.370(5) Å and are consistent with symmetrical bonding of the indenyl ligand to the metal center. The Ti‒(η5-ring centroid) distance is 2.036(4) Å. Addition of 2 equiv of lithium heptamethylindenide (Li+C9Me7−) to the anhydrous halides MCl4 (M = Zr and Hf) in THE gives the metallocene derivatives M(η5- C9Me7)2Cl2 (M = Zr and Hf) in good yield. Zr(η5-C9Me7)2Cl2 crystallizes in the centrosymmetric monoclinic space group P21/n with a = 14.951(12) Å,b = 13.523(6) Å, c = 13.913(11) Å, β = 96.46(3)°, V = 2795.5 Å3, R = 0.041, and Rw = 0.048. The Zr-C distances range from 2.511(4) to 2.612(4) Å, with a mean value of 2.563(4) Å, and are consistent with symmetrical η5-bonding of both indenyl ligands to the metal center. The Zr-(η5-ring centroid) distances are 2.259(4) and 2.255(4) Å with a centroid-Zr-centroid angle of 139.0(4)°. The indenyl ligands are oriented away from the chloride ligands which causes a significant distortion from planarity by folding at the bridgehead carbon atoms. © 1994, American Chemical Society. All rights reserved.
