Synthesis and crystal structures of the chromium(II) and chromium(III) hexafluoroacetylacetonate complexes trans-Cr(hfac)(2)(thf)(2) and Cr(hfac)(3)

摘要

Treatment of a tetrahydrofuran solution of CrCl2(thf) with Na(hfac), hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate, followed by crystallization from diethyl ether, affords the six-coordinate chromium(II) complex Cr(hfac)(2)(thf)(2). The crystal structures of Cr(hfac)(2)(thf)(2) and the chromium(III) complex Cr(hfac)(3) have been determined by single-crystal X-ray diffraction. Cr(hfac)(2)(thf)(2) adopts a trans octahedral geometry, in which the Cr-O(hfac) and Cr-O(thf) distances are 1.936(3) and 2.019(6) angstrom, respectively. Cr(hfaC)(3) is an octahedral compound with a Cr-O distance of 1.943(5) angstrom. Structural comparisons with related molecules are given. (c) 2006 Elsevier Ltd. All rights reserved.