Experimental and theoretical studies of the products of reaction between Ln(hfa)(3) and Cu(acac)(2) (Ln = La, Y; acac = acetylacetonate, hfa = hexafluoroacetylacetonate)

摘要

The new unusual heterobimetallic complex [La(hfa)(3)Cu(acac)(2)(H2O)] (I) was obtained in the reaction La(hfa)(3)center dot 2H(2)O with Cu(acac)(2) in CHCl3. This is the first example of such type of heterobimetallic complexes based on the Cu(acac)(2) species. According to the X-ray single crystal. analysis, complex I crystallizes in the monoclinic space group P2(1)/c, with a = 12.516(3) angstrom, b = 17.757(4) angstrom, c = 17.446(4) angstrom, beta = 93.90(3)degrees and Z = 4. The structure consists of isolated heterobinuclear molecules with the coordination number of La being 9. The molecules are further assembled into dimers via hydrogen bonds. The theoretical modeling of the structure and the properties of parent monometallic complexes Ln(hfa)(3) (Ln = La, Y) and Cu(acac)(2) is described. The comparative theoretical study of lanthanide complexes indicates relations in formation of a heterobimetallic complex to the Lewis acidity of original monometallic complexes. In particular, the Lewis acidity and charge of the central metal ion in Ln(hfa)(3) are the key parameters accounting for the formation of [Ln(hfa)(3)Cu(acac)(2)]. (c) 2006 Elsevier B.V. All rights reserved.