Luminescence enhancement of nanosized ytterbium and europium fluorides by surface complex formation with aromatic carboxylates

Ytterbium 2,6-naphthalenedicarboxylate (Yb2(nda)3·4H2O) and ytterbium 9-anthracenecarboxylate (Yb(ant)3) were obtained for the first time, and it was shown that both of them exhibit ligand sensibilized ytterbium luminescence. Anions ant− and nda2− were tested for the nanoparticle surface modification of YbF3 and model EuF3. The surface modification of the size uniform toroid-like EuF3 nanoparticles with K2(nda) and octahedron-like YbF3 nanoparticles with K(ant) results in the significant luminescence enhancement due to lanthanide carboxylate formation on the particle surface. Such a surface modification leads to the particle size decrease, while their shape remains the same.