Magnetic property, electronic structure, and cationic dye removal ability of CuCP-MOF

Abstract

Metal-organic frameworks (MOFs) draw more and more attentions due to their abundant properties and potential applications in materials science. Developing new MOFs structures often gets unexpected material properties. Herein, we report the properties of a copper [2,2]paracyclophane dicarboxylate MOF (CuCP-MOF). The magnetic properties of both CuCP-MOF and activated CuCP-MOF are investigated. CuCP-MOF shows the triplet state electron paramagnetic resonance spectrum at room temperature due to the antiferromagnetic coupling of the copper(II) paddlewheel (Cu-PW) dimer centers. The MOF has strong intramolecular antiferromagnetic interactions (inside the paddle-wheel dimer centers) and very weak intermolecular interactions, while activated CuCP-MOF exhibits strong intramolecular and intermolecular interactions due to the existence of unpaired Cu(II) centers. We also investigate the electronic structure and semiconductor behavior of CuCP-MOF. The MOF is assigned to direct bandgap semiconductors. Moreover, CuCP-MOF could selectively adsorb cationic organic dyes. By utilizing the synergistic effects on adsorption and photodegradation, we successfully apply CuCP-MOF to organic dye removal.