Journal of Inorganic and Nuclear Chemistry最新文献

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.

Electronic absorption spectra of Fe(III) in some phosphate glasses have been measured at room and near liquid-nitrogen temperatures, in the energy range 11,500–30,000 cm⁻¹. Assuming cubic-field microsymmetry, and taking no account of spin-orbit coupling, it was found that the energies of the five observed bands are accounted for satisfactorily in terms of single values of B, C and Δ using the free-atom representation of the crystal-field theory, provided that a Trees' correction is included. It was found that the simple strong-field representation gives less satisfactory results. The Racah parameters, B and C, were evaluated for Fe(III) in two different phosphate media without a pre-assigned value of the fraction C/B and an empirical value of C/B = 3.60 was determined and applied to other data in the literature.

Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al₂O₃ was carried out over a wide range of NaCl concentration and solution pH. In the medium pH region (pH 5–9) adsorption depends strongly on pH and less on salt concentration. However, in the high pH region (pH above 9), the salt dependence of the distribution coefficient becomes important.

Thermodynamic parameters for in-water-formation of mononuclear complexes of cadmium-halide-thiourea systems, calculated by means of potentiometric measurements at different temperatures and at μ = 1 for KNO₃, are reported.

The synthesis and crystal structure of the title compound are described. The complex crystallizes in the trigonal system, space group P31c with a = 16.053(12), $\text{c = 6.839(8)}\text{A}\text{̊}$ and Z = 2. The structure was solved by the heavy-atom method from 1252 counter reflections, and refined by least-squares methods to R 0.054. Six carboxylate oxygen atoms belonging to the three nearly planar p-amino-salicylate ions fill the equatorial region of the linear uranyl ion, giving the U atom an hexagonal-bipyramidal coordination overall. The hexagon is slightly puckered (± 0.05 Å), bond lengths and angles are as expected [U-O(apical) 1.78(e), U-O(eq) 2.47(2) Å]. The exact water content (and thereafter the Na⁺ coordination) is not entirely certain, but seems to approximate to 6H₂O. The intramolecular hydrogen bond between the phenolic and a carboxylate oxygen atom, present in the free acid, is not destroyed by coordination.

A systematic study of the preparation of synthetic pollucite (CsAlSi₂O₆) by high temperature solid state reaction was performed. Eighteen different combinations of cesium oxide, alumina and silica sources and three firing temperatures were evaluated. The most effective methods of preparing phase-pure pollucite were identified and the chemical compositions of large batches of pollucite prepared by three of these methods were obtained. Reference X-ray powder diffraction data were obtained for the most nearly stoichiometric synthetic pollucite specimen.

The kinetics of the substitution reaction between aquo cupric ion and the nickel(II) complex of ethylene-bis-N,N′-(2,6-dicarboxy)-piperidine (NiEBDP) have been measured, as well as the equilibrium constants associated with the protonation of the metal ion complexes and the rapid formation of dinuclear complexes. The rate data can be expressed by the following rate law: $\text{−}\text{d[NiEBDP]}{}_{\mathrm{T}}\text{d}\text{t}\text{=}\text{k}{}^{\mathrm{<mtext>NiEBDP</mtext>}}{}_{\mathrm{<mtext>Cu</mtext>}}\text{[Cu}{}^{\mathrm{2+}}\text{]+k}{}^{\mathrm{<mtext>NiEBDP</mtext>}}{}_{\mathrm{<mtext>H</mtext>}}\text{[H}{}^{\mathrm{+}}\text{]+k}{}^{\mathrm{<mtext>NiEBDP</mtext>}}{}_{\mathrm{<mtext>Cu,H</mtext>}}\text{[Cu}{}^{\mathrm{2+}}\text{][H}{}^{\mathrm{+}}\text{]}\text{[}\text{NiEBDP}{}^{\mathrm{2-}}\text{].}$ Values of rate constants (25.0°C, μ = 1.25), enthalpies and entropies of activation for the reaction pathways are: k_Cu^NiEBDP, 2.77 × 10⁻²M⁻¹ sec⁻¹, 11.7 kcal/mole, −26.4 cal mole⁻¹ K⁻; k_H^NiEBDP, 3.33 × 10⁻²M⁻¹ sec⁻¹, 14.8 kcal/mole, −15.6 cal mole⁻¹ K⁻¹; and k_Cu.H^NiEBDP, 4.47 × 10⁺¹M⁻¹, 13.9 kcal/mole, −4.3 cal mole⁻ K⁻¹, respectively. The results are interpreted in terms of steric effects arising from the ring structure of the ligand by comparison to kinetic studies of similar systems.