Investigation of properties of rare earth complexes with dibromo-p-methyl-methylsulfonazo by spectral correction technique

The reactions were sensitive between seven rare earth (RE) metals Nd(III), La(III), Ce(III), Pr(III), Sm(III), Eu(III) and Gd(III) and dibromo-p-methylmethylsulfonazo (DBMMSA) in acidic solution. The spectral correction method has been applied in the determination of properties of RE complexes instead of ordinary spectrophotometry. Composition ratios, real molar absorptivities (e) and stepwise stability constants (K) of each of the RE complexes were determined easily because the method eliminated the absorption influence of excess of ligand on complex. Results showed that the cumulative K values of the complexes were between 3,91cross10^14 and 2,34 cross10^28 and the real (not apparent) absorptivity between 8,85 cross10^4 and 2,1212 cross10^5 l mol–1cm–1 at 640 nm.