Synthesis, structure, and tunable white light emission of heteronuclear Zn2Ln2 arrays using a zinc complex as ligand

Abstract

New heteronuclear Zn₂Ln₂ clusters [Zn₂L₂Ln₂(hfac)₆] (Ln = Eu (1), Tb (2) and Dy (3)) have been synthesized based on a flexible Schiff base (H₂L = N,N′-bis(salicylidene)-3,6-dioxa-1,8-diaminooctane) and β-diketonate ligand (hfac = hexafluoroacetylacetonate). The structures of the isomorphous complexes 1–3 were determined by single-crystal X-ray crystallography. Photophysical studies indicate that the short intramolecular distance of Zn⋯Ln allows energy transfer from the Zn₂L₂-based sensitizers to the Eu(III) and Tb(III) centres; the lanthanide luminescence is indeed “lighted up” by the excitation of the zinc complex. More interestingly, white light emission was realized by codoping Eu(III) ion into the Dy(III) complex for the first time.