Facile construction of novel organolanthanide square-planar macrocycles through addition of carbodiimide to an amino group

Abstract

The reactivity of lanthanocene derivatives containing the p-aminothiophenolate ligand towards carbodiimide was examined. Reaction of Cp₂Ln(p-SC₆H₄NH₂)(THF) with RNCNR in THF at room temperature gave four novel organolanthanide guanidinate complexes [Cp₂Ln(p-SC₆H₄N(H)C(NHR)NR)]₄ (R = ⁱPr, Ln = Yb (1a), Er (1b); R = Cy, Ln = Yb (2a), Er (2b)), formed by the addition of the CN double bonds of the carbodiimide molecule to the para-position amino group. Their unique square-planar macrocycle structures have been determined through X-ray single-crystal diffraction analysis. This result provides a potential method for the construction of organolanthanide macrocycles.