Sachin Aditya Ramesh, Sreenivasulu Balija, Brahmananda Rao Cherukuri Venkata Siva, Ammath Suresh, Gopakumar Gopinadhanpillai
Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India.
Homi Bhabha National Institute, Training School Complex, Anushakthinagar, Mumbai 400094, India.
J Phys Chem A. 2024 Sep 19;128(37):7772-7784. doi: 10.1021/acs.jpca.4c02523. Epub 2024 Sep 6.
The complexation behavior of tri--amyl phosphate (TiAP) and tri--butyl phosphate (TBP) ligands with U(VI), Th(IV), and Nd(III) was investigated using density functional theory (DFT). Quantum chemical calculations yielded identical coordination geometries for TBP and TiAP complexes. Calculated complexation energies indicated a preferential extraction of U(VI) followed by Th(IV) over Nd(III), aligning with solvent extraction experiments conducted in the cross-current mode. Notably, during the separation of Th(IV) from RE(III), an increase in Th(IV) loading in the organic phase suppressed RE(III) extraction. Further analysis highlighted the crucial role of structural features (symmetry and dipole moment) in the extraction behavior of complexes. Energy decomposition analysis underscored the essential role of geometric strain and dispersion interaction energies in deciding the stability of the complexes.
使用密度泛函理论（DFT）研究了磷酸三戊酯（TiAP）和磷酸三丁酯（TBP）配体与U(VI)、Th(IV)和Nd(III)的络合行为。量子化学计算得出TBP和TiAP配合物具有相同的配位几何结构。计算得到的络合能表明，U(VI)优先被萃取，其次是Th(IV)，而Nd(III)的萃取较少，这与错流模式下的溶剂萃取实验结果一致。值得注意的是，在从RE(III)中分离Th(IV)的过程中，有机相中Th(IV)负载量的增加抑制了RE(III)的萃取。进一步分析强调了结构特征（对称性和偶极矩）在配合物萃取行为中的关键作用。能量分解分析强调了几何应变和色散相互作用能在决定配合物稳定性方面的重要作用。
