The synthesis and characterization of PTCDA-Co(II), and PTCDA-La(III) fluorescent MOFs

Abstract

Metal organic frameworks (MOFs) are unique porous materials with a high surface area employing variety of organic ligands and metal ion components. Moreover, the possibility of developing different additional features, such as magnetic, thermo-responsive, and fluorescent properties that come from the organic ligands and/or metal ions can methodically increase the industrial application of MOF structures. In this paper, perylene 3,4,9,10 tetracarboxylic dianhydride (PTCDA) based MOFs with fluorescent properties were synthesized using Co(II) and La(III) metal ions as nodules. The disappearance of carbonyl group peaks at 1756 cm−1 from PTCDA molecules confirmed the synthesis of PTCDA-based Co(II) and La(III) MOFs. The SEM image revealed that the prepared PTCDA-Co(II) MOFs are in ellipsoidal shapes, whereas the PTCDA-La(III) MOFs are in rod or fiber-like shapes. The BET surface area of prepared PTCDA-Co(II) and PTCDA-La(III) MOFs were determined as 125.9 m2/g and 29.9 m2/g, respectively. The prepared PTCDA-based Co(II) and La(III) MOF exhibit fluorescent properties, e.g., upon exposure to 465 nm excitation wavelength, they have fluorescence emission intensity of 10,500 and 13,000 (a.u) at 514 and 510 nm wavelength, respectively. The quenching activity of Cu(II), Ni(II), As(III), and Hg(II) metal ions on fluorescence properties of PTCDA-La(III) MOFs were examined. Moreover, it was observed that the prepared PTCDA-Co(II) and PTCDA-La(III) MOF show 82.9 ± 0.4 and 95.4 ± 4.1 % Fe(II) chelating activity at 1400 µg/mL concentration of PTCDA-Co(II) and PTCDA-La(III). Lastly, Quantum yield was calculated as 52 ± 1 % for PTCDA-La(III) MOF.