Change in the relation of band intensities of Eu3+, Sm3+, Tb3+ and Dy3+ ion luminesence spectra in complexes as a function of the number of coordinated ligands

Changes in luminescence spectral band intensities were studied as a function of the number of coordinated ligands with complexes of Eu(III), Sm(III), Tb(III) and Dy(III) with ethylene-diaminetetraacetate (I), sulfosalicylic acid (II), 1,2-dihydroxybenzene-3,5-disulfonic aicd (III) and pyrogallolsulfonic acid (IV). Luminescence spectra were recorded in the range of 15.5-19.1 (5D0→F2 and 7F1 transitions) for Eu(III) complexes, 15.0-18.2 (4Gsub(5/2)→6Hsub(9/2) and 6Hsub(7/2)) for Sm(III) complexes, 16.25-21.0 (5D4→7F5, 7F6 and 7F4) for Tb(III) complexes and 16.5-21.5 kilokaysers (7Fsub(9/2)→6Hsub(13/2), 6Hsub(15/2)) for Dy(III) complexes. The relations of the intensities increased with increasing number of ligands coordinated with a central atomic. In the case of Eu-I, Tb-II, Tb-I and Tb-IV complexes, a linear dependence was observed. Close to linear dependence was found with Sm-I, Sm-II, Dy-I and Dy-IV complexes. The largest increase of the relation was observed with Eu-I, Tb-IV, and Tb-III complexes. The increase in ligand number resulted in the dependence of the same character for both luminescence and absorption spectral bands