Luminescent Spherical Particles of Lanthanide-based Infinite Coordination Polymers with Tailorable Sizes

Infinite Coordination Polymers (ICPs) are compounds usually obtained as spherical particles exhibiting amorphous phases in the powder X-ray diffraction patterns. In the present work, we report an ICP system based on rare-earth ions with pyrazole-3,5-dicarboxylate as linker and malonate as coordination modulator. The compounds exhibit a 2D MOF structure. Three different synthetic routes were used, namely microwave-assisted, solvothermal and gel diffusion. The syntheses yield single-phase spherical particles, which were characterized by PXRD, 1H NMR, CHN, FTIR, TGA, SEM and TEM. Photoluminescence spectroscopy was carried out to study the luminescent properties of the Eu3+ and Tb3+-based samples. With the different-sized particles obtained, we could elucidate the intricate microstructure of the spheres and propose a reason behind the observed amorphous phases in the PXRD patterns.