Abstract 4-Quinolones are a class of heterocycles traditionally known for their biological properties. More recently, those derivatives have gained attention as versatile ligands for the construction of metal-centered molecular materials, such as coordination polymers (CPs), opening new possibilities for environmental applications. In this study, a novel dicarboxylated organic compound, 1-ethyl-4-oxo-1,4-dihydroquinoline-3,6-dicarboxylic acid ( H 2 L ), was synthesized and employed to construct zinc-based materials. The synthetic parameters (temperature, time, modulator type, and modulator/ligand precursor ratio) were systematically evaluated, notably highlighting the replacement of the conventional solvothermal solvent (DMF) with a greener alternative (H 2 O) to synthesize the Zn-based materials. Under optimized conditions, two new materials were obtained, namely Material 1 (synthesized in DMF) and Material 2 (synthesized in H 2 O). Additionally, Material 2 - Zn(L)(H 2 O) n - was obtained as single crystals and structurally characterized via synchrotron X-ray diffraction. As for the application, Material 2 demonstrated an adsorption capacity of 24.6 mg g -1 for the removal of the toxic dye methylene blue (MB). Different adsorption essays revealed that the Langmuir isotherm and pseudo-second-order kinetic model best described the behavior of Material 2 . This material achieved 100% selectivity toward the cationic dye (MB) and demonstrated excellent reusability, with only approximately 10% loss in removal efficiency over three adsorption/desorption cycles. Post-adsorption characterization provided valuable insights into the underlying interaction mechanisms. Together, these results highlight the potential of the developed quinolone-based coordination polymer as an efficient material for environmental remediation applications and underscore the relevance of further exploring this emerging class of compounds. Graphical Abstract
Costa et al. (2026) studied this question.