Morphological, luminescence and gas adsorption studies of Pb(II)-MOFs

In this study, we describe the synthesis of four Lead based organic frameworks (1–4) using 2,5-thiophenedicarboxylic acid (H₂TDC) and 4-mercaptobenzoic acid (H₂MBA) as organic linkers. Lead nitrate and Lead acetate were used as source of Pb⁺² ions. The morphological and other structural aspects of these MOFs were subsequently established on the basis of Fourier transform infrared spectroscopy (FTIR), ¹H NMR, Scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and powder x-ray diffraction technique. Brunauer–Emmett–Teller (BET) studies of these MOFs (1–4) revealed more promising adsorption of N₂ gas by MOF 1 (surface area, 3699 m² g⁻¹) followed by 3 (surface area, 742 m² g⁻¹), 4 (surface area, 382 m² g⁻¹), 2 (surface area, 318 m² g⁻¹). Moreover, these MOFs (1–4) have been investigated for their luminescence activity assigned to ligand-to-metal charge transfer (LMCT). (paper)