Author : Alasedi, Kasim.K.
Polarographic Studies of Praseodymium Europium and Gadolinium Cations and it's Applications in solvent extraction using Some Crown Ethers
journal of kerbala university,
2005, Volume 1, Issue 0, Pages 332-339
In this paper a polarographic behavior of rare earth cations (Pr 3+, Eu3+ and Gd3+) complexes with crown ethers was studied. The factors that effect of diffusion current was investigated, it was found that 0.1M KCl is the suitable supporting electrolyte with drop time of 1.4 sec. Direct current polarography revealed half wave potential E ½ of –1.496V, -1.507V and –1.524V for (Pr 3+, Eu3+ and Gd3+) respectively.
A shift in half wave potential of metal ions to negative values by adding the crown compound to the metal ion indicates the complex formation. The extraction of the complexes of Pr (III), Eu (III) and Gd (III) with crown compounds (B15C5, 18C6, B218C6 and B2 24C8) were performed with picric acid in different organic solvents.
The slope analysis methods indicates that Pr 3+, Eu3+ and Gd3+ forms 1:1 complexes with B15C5, 18C6 and B2 18C6. In addition Pr 3+ form 1:1 complex with B2 24C8 while other ions forms 1:2 sandwich complexes with B224C8.
The results of the extraction of Pr 3+, Eu3+ and Gd3+ are a good agreement with the results obtained polarograpically.