Vikas Kumar, D K Singh, J N Sharma, Sk Musharaf Ali and L Varshney
Bhabha Atomic Research Center, India
Posters & Accepted Abstracts: J Nucl Med Radiat Ther
Two macro-cyclic compounds viz. calix-benzo-crown (CBC) and calix-crown-6 (CC6) has been synthesized indigenously at large scale for selective separtion of cesium from simulated high level liquid waste solution. The solvent extraction studies of Cs(I) ion and some typical metals ions like, Na(I), K(I), La(III), Y(III), Rb(I), Mo(VI), Zr(IV), Sr(II), Ba(II), Ru(III), and Pd(II) with both the ligands in nitric acid medium has been carried out. It was found that the both the ligands exhibited a strong extraction ability and selectivity for Cesium (I) over all the metal ions. In order to explain the high cesium selectivity over sodium ions by theoretically, the three different models has been selected. The structure of Cs & Na metal hydrates and their complexes with CBC and CC6 were optimized at hybrid B3LYP level using SVP basis set in TURBOMOLE 7.0 Package. The gas phase binding energy and free energy indicates the selectivity order: Na+ > Cs+ whereas after suitable hydration of metal and nitrate the order becomes reverse as obtained in the solvent extraction results. In addition to this the DCs value for CBC was found to be higher than CC6. The same trend has been validated in terms of binding energy and free energy of complexion by using same level of theory in gas phase as well as solution phase.
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