Pillared metal organic frameworks for the luminescence sensing of small molecules and metal ions in aqueous solutions

Abstract

Two novel pillared MOFs (metal organic frameworks) [Zn₂(trz)₂(tda)]·DMA CH₃OH (1) and [Zn₂(trz)₂(bpdc)]·DMA (2) were obtained under solvothermal conditions. The resulting MOFs show similar structures but with different interlayer distances based on the different carboxylate ligands. 1 and 2 display a certain degree of framework stability in both acid/base solutions and water. The luminescence intensities of the activated phases 1a and 2a are sensitive to metal ions, particularly Fe³⁺ and Cd²⁺ ions. Furthermore, the luminescent properties of 1a and 2a well dispersed in different solvents have also been investigated systematically, which demonstrate distinct solvent-dependent luminescent spectra with emission intensities that are significantly quenched by acetone, nitrobenzene and trinitrotoluene.