Journal of Inorganic and Nuclear Chemistry最新文献

The solvent extraction of certain heavy lanthanides (dysprosium and ytterbium) by 1-(2-pyridylazo)-2-naphthol (PAN or HL) in carbon tetrachloride has been studied as a function of contact time, the pH of the aqueous phase, the concentration of the extractant in the organic phase and the influence of solvents. The data suggest that the equation for the extraction reaction is $\text{Ln}{}^{\mathrm{3+}}{}_{\mathrm{(aq)}}\text{+3HL}{}_{\mathrm{(0)}}\text{⇌LnL}{}_{\mathrm{3(0)}}\text{+3H}{}^{\mathrm{+}}{}_{\mathrm{(aq)}}\text{(where Ln}{}^{\mathrm{3+}}\text{=Dy, Yb).}$

From the distribution coefficient D, extraction equilibrium constants (K_ex of reaction, two-phase stability constants (β₃^x) for the LnL₃ complexes, pH_0.5, and separation factor (S_Yb/Dy) have been evaluated.

A theoretical and experimental study of the diffusion processes in complex-formation in ion exchangers has been made. The study is based on diffusion-type equations expressing the laws of material balance for the counterions and a co-ion. These equations are complemented by the conditions of electroneutrality and absence of any electric current. In particular, the approximate solutions of the equations suggest that during the initial stages of particle conversion, the degree of conversion depends on the input concentration and is proportional to √(t), the effective diffusion being controlled by the individual diffusion coefficients for the counterions. The exact solution of the problem, for varying relations between the individual diffusion coefficient has been obtained numerically by using computers. The principles thus found have been verified experimentally for the MeM exchange in a carboxylic cation exchanger and for MeMe exchange in a complex formation vinylpyridine cation exchanger, respectively. The experimental data agree with the theoretical deductions.

We have calculated the crystal binding energies and the Gruneisen-Anderson parameters in sixteen NaCl- structure alkali halides using the Born model formulation including the short range repulsive interactions between nearest neighbours and the next nearest neighbours, and the van der Waals dipole-dipole and dipole-quadrupole interactions. The overlap repulsive potential parameters have been calculated from the low temperature crystal data on interionic separation and compressibility data. Values of the Gruneisen parameter are calculated taking into account the volume dependence of Poisson's ratio. The Anderson parameters describing the temperature derivatives of adibatic and isothermal bulk moduli have also been calculated with the help of interionic potential models. Calculations have been performed using the two potential forms for short range repulsive interactions showing an inverse power dependence and exponential dependence on interionic distance. The results obtained are compared with experimental data and also with other theoretical studies.

The kinetic behavior of the reaction between dihalodicarbonylrhodate(I) anions, [RhX₂(CO)₂]⁻¹, where X = Cl, Br, and the chelating agent 2-aminopyridine was investigated spectrophotometrically. The reaction for both halo analogues was found to obey third order kinetics, first order in the complex anion and second order in the 2-aminopyridine concentrations. The third order rate constants for the chloro and bromo complex anions had the values, at 25°C, of 779 and 156 l² mol⁻² min⁻¹, respectively, and the corresponding activation energies were 3.00 and 5.50 Kcal mol⁻¹. A mechanism is proposed to account for these observations.

Cu(II) complexes have been prepared with N-isopropyl-2-picolinamine N-oxide (IPA) employing the perchlorate, tetrafluoroborate, nitrate, chloride and bromide salts. Preparative molar ratios of 4:1 and 2:1 ligand to Cu(II) salt yielded the following unique solids: Cu(IPA)₂X₂(X=ClO₄⁻, BF₄⁻ and NO₃⁻) and Cu(IPA)X₂(X=Cl, Br). Characterization has been accomplished primarily by IR, electronic and ESR measurements of the solid state. IPA bonds as a bidentate ligand via its N-oxide oxygen and amine nitrogen in all of the complexes. Anion coordination occurs in the halogen complexes and the nitrate ions appear to be bound to Cu(II) as monodentate ligands in Cu(IPA)₂(NO₃)₂.

Me₃GeOS(O₂)CH₃ and Me₃GeOS(O)₂CF₃ have been prepared and characterised by their ¹H, ¹³C, ¹⁹F NMR, IR, Raman and mass spectra.

Brown ring compounds have been produced by the reaction of ferrous ion with nitric oxide and with nitrous acid in aqueous solution. Spectroscopic results have showed that the brown color is due to charge-transfer bands associated with the FeNO bond. The cyclic voltammetric experiments indicated that the oxidation of this compound was completely irreversible. The influence of light was to stimulate the charge-transfer process in which the electrons were transferred from the donor orbital into the acceptor orbital, and finally led to the formation of the ion-pair Fe(I)NO⁺ which was assumed to be more electroactive.