Ionic charge, effective

Complexation of Pu is discussed in terms of the relative stabilities of different oxidation states and the "effective" ionic charge of Pu0 and Pu02+2. An equation is proposed for calculating stability constants of Pu complexes and its correlation with experimental values demonstrated. The competition between inner v outer sphere complexation as affected by the oxidation state of Pu and the pKa of the ligand is reviewed. Two examples of uses of specific complexing agents for Pu indicate a useful direction for future studies. 

Hanlon JE, Lawson AW (1959) Effective ionic charge in alkali halides. Phys Rev 113(2) 472-478... 

Charge exchange is important all along the high-LET tracks. The effective ionic charge is determined by cross sections of electron capture and loss, which depend predominantly on the ionic velocity. Electron loss may be simply described by an ionization of the incident ion in its own reference frame due to the impact of medium electrons and nuclei. Following Bohr (1948), Mozumder et al. (1968) wrote the cross section for this process as1... 

Roman numerals in parentheses indicate the oxidation or valence states. These are the effective ionic charges of cerium atoms and ions or as they exist in chemical compounds. 

The plot supplies similar informations as the plot of the reciprocal value of ionic radius of the metal vs k12 described by Eigen and coworkers 107—109). Deviations are considered to be due to ligand field stabilization, the Jahn-Teller effect, or to the effective ionic charge u°). The rate coefficient of hydrated Cu2 + is higher by three orders of magnitude as compared to that of most other elements due to the Jahn-Teller effect the distances of the two water molecules in axial positions are much larger than those of the four water molecules in equatorial positions ni). 

Also, Suchet s method (280) for calculation of an effective charge q, which considers the effect of polarization and the sizes of the atomic radii for the cations and anions, is capable of interpreting the results of chemical shifts AE in X-ray absorption spectra in a satisfactory manner (145, 145a, 248). The effective ionic charge q is defined here as... 

Now we may calculate the effective ionic charge on the potassium in the rock-salt structure. That charge, in units of the electronic charge, is -p 1 minus the contributions from the electrons in p states on the six neighboring... 

Recalculate the effective ionic charge Z and transvcr.se charge ef for alkali halides in the CsC l structure, using the tjg from Table 14-2. 

The acids are chosen so as to illustrate the main effects on the values of k3 j. Values of k13 are, in general, set by the strength of the AH bond, and can be interpreted in thermodynamic rather than kinetic terms. The simplest possible acid recombination reaction is that between the proton and the fluoride ion, which is simply a charged sphere. As expected, this reaction has the extremely high rate coefficient of 1 x 1011 1 mole-1 sec-1. Variations of rate coefficients from this value may be explained in terms of steric effects, ionic charge effects, and anion electronic and solvent rearrangement effects, the latter two usually being connected. 

Rates of reaction between acids and hydroxyl ions are found to follow a similar pattern to rates of reaction between bases and hydrogen ions, in that they are diffusion-controlled on condition that the bond being formed is stronger than the bond being broken, and there are no complicating factors. Variations in the rate coefficients can be explained in terms of steric effects, ionic charge effects, solvent structure effects and intramolecular hydrogen-bond effects. A short list of rate coefficients for... 

Ion-water polarization energies calculated from classical electrostatics represent a large percent of the total pair interaction energy. If this contribution is added to Coulombic and short-range functions, the total energy differs substantially from the ab initio curve. We conclude that the effective ionic charges used in the Coulombic term implicitly include the effect of ion-water polarization. 

Here, g, is the effective ionic charge, Pi is the mobility, and N is the number of mobile defects. 

Preceding cyclovoltammetric studies proved that on reduction in aprotic DMF solution (ch+ < 0.1 ppm), its second and reversible half-wave potential is lowered by 0.6 V( ) on addition of the soluble salt Li [B"(C6H5)4] and simultaneously becomes irreversible [13] (Fig. 14 CV). The presumed microscopic reduction pathway in the presence of excess lithium cation, which, owing to its small ionic radius (ru+ = 60 pm), possesses a high effective ionic charge, is supported by independent ESR/ENDOR measurements [13] in THF (Fig. 14 ESR) the solvated radical anion M ", with two equivalent quinone hydrogen atoms, can be detected by its (1 2 1) triplet. In the subsequently formed contact ion-pair radical [M Li ] , the Li countercation docks at the quinone radical anion. Due to reduced symmetry > Cs, a doublet of doublets ESR signal pattern results. 

The quantity S is related to the concentration of oscillators N, their reduced mass m, the resonance frequency coq, and the phenomenological effective ionic charge e [46] by the equation... 

Robertson 1(1979) Electronic structure of GaSe, GaS, InSe and GaTe. J Phys C 12 4777-4790 Wakamura K, Aral T (1981) Empirical relationship between effective ionic charges and optical dielectric constants in binary and ternary cubic compounds. Phys Rev B 24 7371-7379 Liebau E, Wang X (2005) Stoichiometric valence versus structural valence Conclusions drawn from a study of the influence of polyhedron distortion on bond valence sums. Z Krist 220 589-591... 

KucharczykW (1991) Pressure dependence of effective ionic charges in alkali halides. JPhys Chem Solids 52 435-436... 

Comparison of the empirical parameters with those calculated within the framework of the exchange charge model (results in tables 7a-d, theory rows), shows that correlations between values of Bpq are mainly determined by the spatial structure of the lattice these values may be found by determining the scale factors Ga, Gs, G (see eq. 49) and effective ionic charges qx from comparison of the calculation results with the data of measurements. 

RALEIGH Yes, the chemisorbed ion experiences, with respect to the bulk, both a chemisorption energy and an electrostatic energy [so long as it maintains even a partial effective ionic charge]. The electrostatic energy,... 

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