摘要
According to the experiment results of X-ray diffraction and IR, the reduced partition function ratio (RPFR) and the contribution of various related vibration modes of uranium-crown ether complex (DCH18C6·H_3O)_2UO_2Cl_4 were theoreticallv calculated in detail. The equilibrium constant K_(eq) (that is, the single stage isotopic separation factor α) of exchange reaction for uranium isotopic chemical exchange system UO_2^(2+)(H_2O)_5—(DCH18C6.H_3O)_2UO_2Cl_4 is estimated to be 1.000746 at 12℃ and 1.000672 at 29℃, respectively, which are quite close to the experimental values 1.0010±0.0002 arid 1.0012±0.0004. Theoretical analysis shows that in the course of forming the complex of uranium with crown ether, the coordinated water of uranium is stripped, which performs a key action on the remarkable isotope effect for this system.
According to the experiment results of X-ray diffraction and IR, the reduced partition function ratio （RPFR） and the contribution of various related vibration modes of uranium-crown ether complex （DCH18C6·H<sub>3</sub>O）<sub>2</sub>UO<sub>2</sub>Cl<sub>4</sub> were theoreticallv calculated in detail. The equilibrium constant K<sub>eq</sub> （that is, the single stage isotopic separation factor α） of exchange reaction for uranium isotopic chemical exchange system UO<sub>2</sub><sup>2+</sup>（H<sub>2</sub>O）<sub>5</sub>—（DCH18C6.H<sub>3</sub>O）<sub>2</sub>UO<sub>2</sub>Cl<sub>4</sub> is estimated to be 1.000746 at 12℃ and 1.000672 at 29℃, respectively, which are quite close to the experimental values 1.0010±0.0002 arid 1.0012±0.0004. Theoretical analysis shows that in the course of forming the complex of uranium with crown ether, the coordinated water of uranium is stripped, which performs a key action on the remarkable isotope effect for this system.
基金
Project supported by the National Natural Science Foundation of China.
