Structural characterization of zirconium isopropoxide precursors modified by di- and trichloroacetic acids

Reactions of Zr(OiPr)4(PriOH) with di- and trichloroacetic acid in 1:1 molar ratio in toluene gave the products Zr2(μ-OiPr)2(μ-OOCCHCl2)(OiPr)4(OOCCHCl2)(HOiPr) (1) and Zr2(μ-OiPr)2(μOOCCCl3)(OiPr)4(OOCCCl3)(HOiPr) (2), respectively, in quantitative yields. The molecular geometry of both (1) and (2) is constituted by a slightly distorted edge-shared bioctahedron and both have almost similar bond dimensions. Addition of dichloroacetic acid in 1:2 molar ratio to Zr(OiPr)4(HOiPr) in toluene although yielded the bis-substituted crude product Zr(OiPr)2(OOCCHCl2)2(HOiPr) (3) but its solution in toluene left for crystallization formed a tri-nuclear oxo product Zr3(μ3-O)(μ-OiPr)2(μ-OOCCHCl2)3(η-OOCCHCl2)2(OiPr)3 (3a). The three zirconium atoms in the structure of (3) are forming an isosceles triangle with a triply bridged oxo moiety at its center.