Reactivity of lanthanocene hydroxides toward carbodiimide and CO2: Synthesis and characterization of lanthanide ureido and carbonate complexes

[Cp2Ln(μ-OH)(THF)]2 react with 2 equiv of CyNCNCy (Cy = cyclohexyl) to form [Cp2Ln(μ-OC(NHCy)NCy)]2 (Ln = Er (1-Er), Y (1-Y)), while treatment of [Cp2Ln(μ-OH)]2(μ3-O)LnCp(THF) with CyNCNCy affords the addition/rearrangement products [Cp2Ln(μ3-O)(μ-OC(NHCy)NCy)LnCp]2 (Ln = Yb (3-Yb), Er (3-Er)). Compounds [(Cp2Ln)2(μ3-CO3)(THF)]2 (Ln = Yb (4-Yb), Er (4-Er)) can be obtained by treatment of [Cp2Ln(μ-OH)(THF)]2 with CO2 immediately followed by the reaction with the corresponding Cp3Ln. Complexes 1–4 were characterized by elemental analysis, spectroscopic properties and X-ray single crystal diffraction analysis.

Graphical abstractTwo new selective additions of lanthanocene hydroxides to carbodiimide and CO2 have been established, by which a series of new ureido and carbonate complexes are synthesized.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Selective additions of lanthanocene hydroxides to carbodiimides. ► Selective additions of lanthanocene hydroxides to carbon dioxide. ► An efficient method for the construction of ureido and carbonate ligands. ► Regioselective introduction of a variety of substituents onto the hydroxide ligand.