Synthesis and structure of the diglyme-bridged lead hexafluoroacetylacetonate complex [Pb(hfac)2(μ-η3:η1-diglyme)]2

The hexafluoroacetylacetonate (hfac) chemistry of lead was investigated to make comparisons with the similarly sized lanthanides that form air stable Ln(hfac)3(diglyme) complexes. [Pb(hfac)2(μ-η3:η1-diglyme)]2 was obtained from PbO, (MeOCH2CH2)2O, and H(hfac) and was found to exist in the solid state as chiral pairs linked via diglyme. The metal is eight coordinate, but has sufficient vacant space in the coordination sphere to be considered to have an hemi-directed coordination environment. In contrast to the Ln(hfac)3(digyme)/K reactions that generate [LnF(hfac)3K(diglyme)]2 fluoride complexes, the potassium reduction of the lead complex gave only [(18-crown-6)K(hfac)]n in pure form, a complex that displays bridging CF3 linkages in the solid state.

The title complex is readily made from PbO and Hhfac in the presence of diglyme. The volatile complex exists as enantiomeric pairs linked by bridging oxygens, as shown here.Figure optionsDownload as PowerPoint slide