[en] The Mossbauer spectra of compounds with general formula [(π-C₅O₅)Fe-(CO₂)]₂Sn (X)(Y) were studied. The corresponding parameters showed that the parameters for iron were assentially independent on the nature of X and Y. The alternation of X and Y caused the change in s electron density through the shielding of s electron or the substitutents inductive effect and subsequently caused the change of tin isomer shifts. The fact that X and Y groups had little effect on iron parameters might be a good evidence for the absence of π interaction between Fe and Sn

[en] A study of the synergistic extraction of uranium (VI) from sulphuric acid solution with the chelating agent 1-phenyl-3-methyl-4-(2'-chloro benzoyl)-pyrazolone-5 (PMCBP) together with di(2-ethylhexyl) phosphoric acid (HDEHP) and also mono-(2-ethylhexyl)-2-ethylhexylphosphate (HEHEHP) is described. The experimental results indicate that the synergistic extraction species is not an individual complex, but rather a mixture of UO₂HA₂X and UO₂HA₂HXX'. The mechanisms of extraction is discussed

[en] The THF adducts of the bis (cyclopentadienyl) praseodymium(III) and bis (indenyl) lanthanoid(III) chlorides (C₅H₅)₂PrCl.nTHF (n = 0, 1, 2) and (C₉H₇)₂LnCl.nTHF (Ln = Pr, Nd, Sm, Gd; THF = tetrahydrofuran; n = 3, 4) have been prepared by the reaction of the anhydrous metal trichlorides with sodium cyclopentadienide or indenide (the molar ratio of rare earth to sodium salt 1:2) in THF. The presence of the above new compounds was verified by elemental analysis, thermal analysis, infrared and photoelectron spectroscopy

[en] We present some information about the structures, thermogravimetric losses, magnetic susceptibilities and reflective spectra of rare earth-bismuth complex oxide. The crystal structures for RE-Bi complex oxide system may be classified into three types: (1) the fluorite single phase (belong to cubic system) for Pr-Bi and Tb-Bi oxide solid solutions; (2) La-type (light rare earth) rhombohedral single phase for La-Bi, Nd-Bi, Sm-Bi, Eu-Bi and Gd-Bi oxide solid solutions; (3) the mixed phases of fluorite type (F) for Ce-Bi, Dy-Bi, Ho-Bi, Er-Bi, Tm-Bi, Yb-Bi, Lu-Bi and Y-Bi oxide solid solutions with corresponding C-type RE₂O₃. The lattice paremeters decrease with the increase of RE atomic numbers. This change is caused by the lanthanide contraction. With the increase of RE atomic numbers the thermal stabilities of RE-Bi oxide solid solutions decrease and Gd break occurs, the magnetic susceptibilities show a periodic change with two maxima at Nd and Ho. Moreover, the UV absorption band in the reflective spectra shifts to longer wavelength by the presence of Bi-O component, hence it might be used as the starting materials of colour lens glass for UV-absorption

[en] Lanthanide ions were used as NMR probes to study the conformation distributions of cytidine (5'-CMP), adenosine (5'-AMP), and inosine (5'-IMP) in acidic aqueous solutions. The experimental data of pseudo-contact shift together with the data of spin-lattice relaxation rate as well as spin-coupling constants of ¹H spectra were processed by computer. The results show that in aqueous solutions the conformations of the nucleotides exist in equilibrium as a group of conformers. In comparison with crystalline state, the dihedral angles around single bonds and the puckering forms of ribose ring have changed to some extent. However, the base groups are still in anti-forms

[en] The ion exchange kinetics of ²³⁵UO₂²⁺-bar - ²³⁸UO₂²⁺, UO₂²⁺ - H⁺-bar and UO₂²⁺ - H⁺ were studied with macrorecticular sulfonic ion exchange resin. It was clarified that the latter two processes start from film diffusion transiting gradually to inner diffusion and the former process begins at inner diffusion as soon as dead time passed. These results were explained by boundary mass-transfer models based on absorption double electric layer theory. Each inner diffusion coefficient D-bar of these three processes was determined and the results showed that the coefficient D-bar of the first and second processes are nearly equal to each other and that of the last process remains only 1/5 as that of the second one

[en] The acid dissociation constants of 3, 6-bis (methyleneiminodiactic acid) catechol (CBMIDA), the stability constants of its Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II), Fe(III), Th(IV) and U(VI) complexes and the protonation constants of the metal complexes were determined pH-metrically in aqueous solutions at 25.0 ± 0.1 deg C in the presence of 0.1 mol · dm^-3 potassium nitrate. The mechanism of the stepwise acid dissociation equilibria of CBMIDA was presented and the coordination forms of the metal complexes were discussed

[en] A pNa method used for determining the stability constants is reported and applied to the study on coordination reaction of benzo-15-crown-5 (L1) and 4'-nitrobenzo-15-crown-5 (L2) with 10 rare earth ions in methanol solution, and their stability constants are calculated according to the formation of 1:1 coordination compounds. It is found that the coordination capability of L2 to rare earth ions is stronger than that of L1, especially with heavy rare earth. The coordination behavior of L1 and L2 towards yttrium (III) is studied under the same conditions. It is observed that log KY3+ of L2 is larger than that of L1, which is similar to the regularity that the coordination capability of L2 with Ln3+ is stronger than that of L1. This shows that L1 and L2 are also similar as to the property of solution coordination compounds of yttrium and lanthanum with the two ligands. Comparing the log K of the coordination compounds formed by coordinating of the 3 kinds of ions whose radii are similar but their electric charges are different with the ligand L1, the following result is obtained: logKNa+ > logKCa2+ > logKLa3+, but with L2, the result is logKCa2+ > logKLa3+ > logKNa+

[en] A new ternary synergistic extracting system composed of two chelate extracting ligands and one ion association ligand, namely AAC species, has been studied. As a preliminary study, uranyl perchlorate was extracted by the binary system of thenoyltrifluoroacetone (HTTA) and of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP) with tetraphenylarsonium chloride (C₆H₅)₄AsCl in chloroform solution. The binary synergistic equilibrium constants were determined to be log β_A1C = 3.97 [HTTA + (C₆H₅)₄AsCl system] and log β_A2C = 4.86 [HPMBP + (C₆H₅)₄AsCl system] respectively. The present work was to investigate the ternary synergistic extracting mechanism of uranium (VI). It was found that synergic effect occurred during the extraction of uranyl perchlorate with the chloroform solution of HTTA + HPMBP + (C₆H₅)₄AsCl and the principle of minimum density of electric charge plays an important role in this system. The formation of a ternary extracted complex [(C₆H₅)₄As]-UO₂(ClO₄)(TTA)(PMBP) was confirmed by the slope method, and the perchlorate was determined by the Methylene blue spectrophotometric method. The equilibrium constant was calculated to be log β_A1A2C = 5.52

[en] This paper described Ln 3d_5/2 photoelectron spectra and satellite phenomena for lanthanide complexes of benzo-15-crown-5 and dibenzo-18-crown-6. Changes in electronic structure and covalency for the complexes were discussed. Regular variation between Ln 3d_5/2 binding energy and 1/γ appears