Conductometric studies of the thermodynamics complexation of Yb3+ and Nd3+ ions with 4 ,4 (5 )-Di-tert-butyldibenzo-18-crown-6 ligand in water solvent

The thermodynamics and complexation of crown ethers have been mainly studied with lanthanides cations in water and in various nonaqueous solvents [1, 2]. Crown ethers and related compounds are capable of forming complexes with many metal salts, with organic salts and with many neutral organic molecules. For thermodynamic stability and stoichiometry studies of these complexes, a large variety of methods has been reported [3]. In this work study the influence of cation size and solvent properties on the interactions of some lanthanides metal ions with 4 , 4 (5 )-Di-tert-butyldibenzo-18-crown-6, and The formation constants of the resulation 1:2 complexes were calculated from the computer fitting of the molar conductance in various mole ratios and found that complexes to vary in the order of Nd3+> Yb3+at 25ºC.