Improving Water-Stability and Porosity of Lanthanide Metal–Organic Frameworks by Stepwise Synthesis for Sensing and Removal of Heavy Metal Ions

Employing polynuclear cluster-based nodes can make metal–organic frameworks have higher porosity and good stability. In this work, by using compound [(Me₂NH₂)­Eu­(L)­(DMA)­(H₂O)]_<i>n</i> (<b>1</b>) as reactant, polynuclear cluster-based [(Me₂NH₂)­Eu₅(L)₄(DMA)₄(H₂O)₆]_<i>n</i> (<b>2</b>) (H₄L = 1,3-bis-[3,5-bis­(carboxy)­phenoxy]­propane) can be synthesized successfully. Although two compounds are all three-dimensional microporous anionic frameworks, the water-stability and porosity of compound <b>2</b> is higher than that of compound <b>1</b>. Compound <b>2</b> is assembled by two kinds of multinuclear metal units in which one Eu­(III) ion center is hexa-coordinated. The luminescence studies exhibited that compound <b>2</b> performed a highly selective photoluminescence quenching toward nitrobenzene and Fe­(III) ion. So, compound <b>2</b> can be possibly developed as a dual functional chemosensor for detecting Fe­(III) ion and nitrobenzene. Furthermore, compound <b>2</b> also has the potential ability to absorb and remove toxic metal ions from aqueous solution