Luminescent investigation of the complex formation of trivalent f-elements (Eu, Sm, Dy, Pr, Nd, Yb, Cm) ions with heteropolymolybdotungstate anions

A detailed luminescence study of Eu, Sm, Dy, Pr, Nd, Yb, Cm complexes with mixed heteropolymolybdotungstate anions (HPA) of different composition was carried out. Luminescence spectra do not depend on the number of Mo atoms in HPA. When Mo atoms are substituted for W atoms, intensity of the complex luminescence increases, but in the presence of six Mo atoms energy transfer for rare earth elements decreases sharply and for the complexes with pure heteropolymolybdate anions it is equal to zero. In case of metal-ligand ratio equal to 1:2, stability of the complexes decreases with the growth in Mo atoms number