Heteroligand luminescent europium(III) complexes with quinaldic acid and neutral ligands were prepared. The compounds obtained were characterized by elemental analysis, X-ray diffraction, thermal gravimetric analysis, and IR spectroscopy. The composition of the complexes was determined. In the course of thermolysis, the nitrogen-containing ligand molecule is eliminated in one step with exo- and endothermic effects. The compounds are thermally stable up to 260°С. The synthesized coordination compounds were introduced into low-density polyethylene to obtain luminescent polymer materials.