CRYSTAL STRUCTURE OF TRIS(HEXAFLUOROACETYLACETONATO)-PI-CYCLOPENTADIENYLZIRCONIUM

The structure of tris(hexafluoroacetylacetonato)-π-cyclopentadienylzirconium, (π-C5H5)Zr(CF3COCHCOCF3)3, has been elucidated by single-crystal X-ray techniques and refined to a conventional residual of 6.1%. A total of 2009 observations above background, collected by counter methods, was used in the determination. The space group is monoclinic, P21/n, with a = 13.48 (2) Å, b = 23.03 (2) Å, c = 8.95 (1) Å, and β = 94°52(8′). The calculated density is 1.86 g cm-3 for four molecules per unit cell. The molecular complex exhibits pentagonal-bipyramidyl geometry. Five of the six coordinated oxygen atoms lie in an equatorial plane about the zirconium while the sixth oxygen and the π-cyclopentadienyl group occupy the two axial positions. The zirconium atom is displaced 0.39 Å from the equatorial plane toward the latter group. Two of the chelate rings exhibit folding of 4.5 and 8.4°, respectively, about the O…O line while the third ring, occupying axial and equatorial oxygen atom coordination positions, is planar. The two Zr-O distances in this ring differ by 0.10 Å. © 1969, American Chemical Society. All rights reserved.