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)](n) (1) as reactant, polynuclear cluster-based [(Me2NH2)Eu-5(L)(4)(DMA)(4)(H2O)(6)](n) (2) (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 2 is higher than that of compound 1. Compound 2 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 2 performed a highly selective photoluminescence quenching toward nitrobenzene and Fe(III) ion. So, compound 2 can be possibly developed as a dual functional chemosensor for detecting Fe(III) ion and nitrobenzene. Furthermore, compound 2 also has the potential ability to absorb and remove toxic metal ions from aqueous solution.