Modulator-Induced Zr-MOFs Diversification and Investigation of Their Properties in Gas Sorption and Fe3+Ion Sensing

In this paper, we synthesized three Zr-MOFs (Zr-SXU-1, Zr-SXU-2, and Zr-SXU-3) composed of identical ligands and metal clusters by using tetratopic carboxylic ligand PBPTTBA as the ligand and benzoic acids as modulators. These three Zr-MOFs showed different structures and topologies, and the connectivity of the Zr clusters varied from 8 in Zr-SXU-3, to 10 in Zr-SXU-1, and finally to 12 in Zr-SXU-2 due to the modulators used. Among them, Zr-SXU-1 represents an unusual 6-node network and [6(10)(11)7] transitivity. Besides, Zr-SXU-2 can only be obtained by using ditopic carboxylic acid as a second modulator when using benzoic acid as the main modulator, which is not reported in other Zr-MOFs synthesis. The adsorption and luminescence tests demonstrated their potential as gas reservoirs, separators, and sensors and also showed the importance of structure topologies to the applications.