X-ray structural study of fluorinated β-diketonate complexes of zirconium(IV)

Three novel complexes of zirconium(IV) are prepared and characterized by single crystal X-ray diffraction: zirconium(IV) pivaloyltrifluoroacetonate Zr(ptac)(4), zirconium(IV) trifluoroacetylacetonate Zr(tfac)(4), and zirconium(IV) hexafluoroacetylacetonate Zr(hfac)(4). Crystal data for C32H40F12ZrO8: a = 19.9842(6)angstrom, b = 11.8417(3)angstrom, c = 16.4831(5)angstrom; beta = 95.2880(10)degrees, monoclinic, space group Cc, Z = 4, d (calc) = 1.491 g/cm(,3) R = 0.061. Crystal data for C20H16F12ZrO8: a = 21.5063(15) angstrom, b = 7.9511(5) angstrom, c = 16.0510(10)angstrom; beta = 113.736(4)degrees, monoclinic, space group C2/c, Z = 4, d (calc) = 1.860 g/cm(,3) R = 0.047. Crystal data for C20H4F24ZrO8: a = 15.3533(13) angstrom b = 20.2613(15) angstrom, c = 19.6984(17) angstrom; beta = 95.828(2)degrees, monoclinic, space group P2(1)/c, Z = 2, d (calc) = 2.004 g/cm(3), R = 0.078. All the structures are molecular and include isolated mononuclear Zr(beta-dik)(4) complex molecules. Coordination environment of zirconium atom is made by eight oxygen atoms of four beta-diketonates; the coordination polyhedron is an almost regular square antiprism. The Zr-O distances fall within 2.14-2.23 angstrom. Complexes in the structures are joined by van der Waals interactions. Using the structural data, the van der Waals energies of crystal lattices of the studied compounds are calculated by the atom-atom potential method.