Two multifunctional Eu-MOFs with dual photochromic and luminous centers for multiple optical switches and anti-counterfeiting properties

Abstract

In this work, two multifunctional Eu-MOFs with dual photochromic and luminous centers, formulated as Eu3[(ipbp)4·6H2O]·3H2O (1) and Eu[(ipbp)·(p-BDC)·H2O] (2) (ipbp = 1-(3,5-isophthalic acid)-4,4′-bipyridine chloride, p-BDC = terephthalate), were successfully constructed by solvothermal reactions. The carboxylate pyridine ligand gives the two frameworks excellent photochromic properties, while the metal europium endows the two compounds splendid luminous properties. In addition, the application of the two compounds in three kinds of optical switches is further demonstrated. Finally, the two compounds with dynamic multicolor anti-counterfeiting properties were also explored. This work not only proposed bicentric light-emitting and color-changing materials, but also provided a new strategy for studying multiple optical switches and dynamic anti-counterfeiting.