Luminescent Sensing of Volatile Organic Compounds Using a Zn-based Coordination Polymer with Tunable Morphology

Here we report the mechanochemical synthesis of Zn(ADB)n coordination polymer (ADB: azobenzene 4, 4′-dicarboxilic acid) in good yield, which provides advanced over conventional route as it is simple, faster, cost-effective and reproducible. Both coordination polymers were characterized by X-ray powder diffraction (PXRD), field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and simultaneous thermal analysis. PXRD studies showed that both materials exhibited the same pattern, proving the presence of the crystalline coordination polymer core. FESEM micrograph images showed plate shape microstructures with a length of 10 µm, and a thickness in range from 14 to 21 µm, which suggested that synthetic routes affect the coordination polymer morphology. The resulting coordination polymers have low porosity with surface areas around from 1.92 to 1.25 m2 g− 1 and pore sizes in range from 0.36 to 0.61 nm for mechanochemical and room temperature stirring routes, respectively. In a preliminary fluorescent sensing study, the coordination polymer soaked with different volatile organic compounds showed noticeable shifts of the emission band in comparison with the same materials free solvent.