Synthesis and photoluminescence analysis of europium(III) complexes with pyrazole acid and nitrogen containing auxiliary ligands

Four red photoluminescent europium(III) complexes have been synthesized by using fluorinated carboxylate ligand, 1-(4-methoxyphenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid as main ligand and bathophenanthroline, 1,10-phenanthroline and 2,2-bipyridyl as auxiliary ligands, through solution precipitation approach. The complexes possess an optimum thermal stability, which is sufficient for organic light emitting diodes fabrication. Under ultraviolet excitation, the complexes display an intense emission peak of europium ion, which makes them a promising red color emitter in display devices. Internal quantum efficiency, color coordinates, Judd-Ofelt parameters, and energy transfer mechanism have been explored. The investigated antimicrobial and antioxidant activity suggest that the synthesized complexes are potent antimicrobial and antioxidant agents.