Polynuclear Heteroligand Yb(III)–Er(III) Complexes as Potential Upconversion Materials

Abstract

The synthesis of complexes LnI(C₆F₅O)₂ and LnCp(L)₂ (Ln = Er, Yb; L = C₆F₅O, SON^F), which are convenient precursors for the preparation of heteroligand bimetallic complexes, is described. The structures of YbI(C₆F₅O)₂(DME)₂ (I), CpEr(C₆F₅O)₂(DME)[(C₂H₅)₂O] (III), and CpYb(SON^F)₂(DME) (VI) were established by X-ray diffraction (CIF files CCDC (nos. 1902963 (I), 1902964 (III), and 1902965 (VI)). The developed methods were used to prepare heteroligand bimetallic Yb(III)–Er(III) complexes (C₆F₅O)₂Yb[µ-(CF₃)₂CHO]₂Er(C₆F₅O)₂ and {(SON^F)₂Yb[µ-(CF₃)₂CHO]₂-Er(SON^F)₂}_x, which showed metal-centered emission inherent in Yb³⁺ and Er³⁺ ions λ_em = 985 and 1540 nm, respectively. This suggests that the obtained compounds can serve as promising upconversion materials.