Influence Of The Size Of Colloid Nanorized Systems On The Luminescence Intensity Of Eu(III) And Tb(III) Complexes

Abstract

Optimal conditions for complexation of Tb(III) ions with norfloxacin, keterolac, 2-oxo-4-hydroxyquinoline-3-carboxylic acid amide derivative and Eu(III) with oxytetracycline were established. The dependence of the luminescence intensity (Ilum) of complexes on the acidity of the medium, the type of solvent, the luminescent characteristics of complex compounds were determined, the average lifetime of the excited state of europium and terbium ions in complex compounds in the presence and absence of cationic, anionic and nonionic substances, and the size of colloidal nanoscale systems based on these complexes is established. Analysis of the influence of the type of surfactants on the processes of excitation energy transformation in the complexes of Eu(III), Tb(III) with some drugs was studied by the method of dynamic light scattering. It was found that the luminescence intensity of colloidal nanoscale systems based on Tb(III) and Eu(III) complexes increases in the presence of cationic surfactants(СPC) and nonionic surfactant (Triton X-100), which is associated with a decrease in their size, although other factors may be involved: synergetic effects, displacement of water molecules from the internal coordination sphere of the complex and increasing the rigidity of the complex during coordination with surfactants. Exceptions are Eu – OxTc, Tb-R2, Tb-Nor complexes in the presence of anionic surfactants (SDS), the size of which increases, which can be explained by the formation of triple complexes. The intensity of their luminescence increases, because in these cases there is a displacement of water molecules from the internal coordination sphere of the complex in coordination with SDS.