Cadmium metal–organic frameworks: Ln3+ ion functionalized assembly, fluorescence tuning and polymer film preparation

Abstract

A series of lanthanide ion activated cadmium metal–organic frameworks, Ln³⁺@Cd-MOFs (Ln = Eu, Tb, Sm, Dy, Cd-MOF = {[(Me₂NH₂)₂]·[Cd₃(5-tbip)₄]·2DMF}_n, 5-tbipH₂ = 5-tert-butylisophthalic acid), are prepared using the cation exchange method and their photophysical properties are investigated. Dy³⁺@Cd-MOFs exhibit white light output; and especially when two different lanthanide cations (Sm³⁺,Tb³⁺) are loaded into the Cd-MOF at the ratio of Sm³⁺_0.98/Tb³⁺_0.02, its luminescent color can be tuned into white. In addition, the luminescence properties of the Eu³⁺ and Tb³⁺ coactivated Cd-MOF with varying ratios are also discussed. Simultaneously, we obtain the size-reduced Cd-MOF (Cd-MOF-2) with the assistance of sodium acetate, while other conditions remain unchanged. Additionally, a polymer film is prepared with the use of Ln³⁺@Cd-MOF-2 for further application.