CRYSTAL AND MOLECULAR STRUCTURES OF BIS (CYCLOPENTADIENYL) BIS (2,4,6-TRICHLOROPHENOXY)TITANIUM, Cp 2 Ti(OC 6 H 2 Cl 3 -2,4,6) 2 (I) AND TETRAKIS(CYCLOPENTADIENYL)BIS (4-CHLOROPHENOXY)-μ-OXO-DIZIRCONIUM,[Cp 2 Zr(OC 6 H 4 Cl-p)] 2 O (II)

Abstract

The crystal and molecular structures of (Ⅰ) and (Ⅱ) have been determined from single-crystal, X-ray diffraotion data collected by counter methods. Compound (Ⅰ) crystallizes inthe monoclinic space group C 2/c with a=19.618(11) ?, b=9.356(4) ?, c=15.985(8) ?,β=128.84 (3)°, Z=4. The molecule possesses C_2 point symmetry. Compound (Ⅱ) erystallizesin the monoclinic space group P 2_1/a with a=8.329(2) ?, b=36.509(13) ?, c=10.647(4)?, β=96.04(2)°, Z=4. The oxo-bridge links two [Cp_2Zr(OC_6H_4Cl-p)] units together withthe bond angle Zr-O-Zr of 161.1(9)°. The relatively shorter Zr-O bond lengths show the pre-sence of partial double-bond character. Both Ti and Zr atoms have d° electronic configura-tion in (Ⅰ) and (Ⅱ). The M-O bonds of the two compounds are discussed.