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)_2...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.展开更多
Recently, the structure of the black soap film(BSF)has been found to be similar to biomembrane, and therefore has been used as a model to study the functions, properties and structures of the biomembrane.
The title compound was synthesized by extracting nranylchloride in HC1 system using dicyclohexyl-18-crown-6 as extraction agent. The absorption peaks 1090 cm^(-1) and 912 cm^(-1) in IR spectrum result from frequence r...The title compound was synthesized by extracting nranylchloride in HC1 system using dicyclohexyl-18-crown-6 as extraction agent. The absorption peaks 1090 cm^(-1) and 912 cm^(-1) in IR spectrum result from frequence red-shift of anti-symmetric stretch vibration of C—O—C of crown ring and [OUO] group, respectively.X-ray diffraction analysis results in its crystallographic parameters: triclinic system, space group P; a=10.183(3), b=10.606(3), c=12.850(6), α=72.09(3), β=85.97(4), γ=86.14(2)°, V=1315.7, z=1. The structure was solved by heavy atom method. Structure refinements converged to final R=0.062, R_w=0.061. U atom is situated on the symmetry center and coordinated by four chlorine atoms and two oxygen atoms to form a square bipyramid coordination polyhedron. The H_3O^+ group is embedded in the crown ring and connected with three crown oxygen atoms via hydrogen bonds.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘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.
基金Project supported by the National Natural Science Foundation of China.
文摘Recently, the structure of the black soap film(BSF)has been found to be similar to biomembrane, and therefore has been used as a model to study the functions, properties and structures of the biomembrane.
基金Project supported by the National Natural Science Foundation of China.
文摘The title compound was synthesized by extracting nranylchloride in HC1 system using dicyclohexyl-18-crown-6 as extraction agent. The absorption peaks 1090 cm^(-1) and 912 cm^(-1) in IR spectrum result from frequence red-shift of anti-symmetric stretch vibration of C—O—C of crown ring and [OUO] group, respectively.X-ray diffraction analysis results in its crystallographic parameters: triclinic system, space group P; a=10.183(3), b=10.606(3), c=12.850(6), α=72.09(3), β=85.97(4), γ=86.14(2)°, V=1315.7, z=1. The structure was solved by heavy atom method. Structure refinements converged to final R=0.062, R_w=0.061. U atom is situated on the symmetry center and coordinated by four chlorine atoms and two oxygen atoms to form a square bipyramid coordination polyhedron. The H_3O^+ group is embedded in the crown ring and connected with three crown oxygen atoms via hydrogen bonds.
