Outlying charge

The mere exposure of diphenyl-polyenes (DPP) to medium pore acidic ZSM-5 was found to induce spontaneous ionization with radical cation formation and subsequent charge transfer to stabilize electron-hole pair. Diffuse reflectance UV-visible absorption and EPR spectroscopies provide evidence of the sorption process and point out charge separation with ultra stable electron hole pair formation. The tight fit between DPP and zeolite pore size combined with efficient polarizing effect of proton and aluminium electron trapping sites appear to be the most important factors responsible for the stabilization of charge separated state that hinder efficiently the charge recombination. 

K. Baldridge and A. Klamt, First principles implementation of solvent effects without outlying charge error, J. Chem. Phys. 106 6622 (1997). 

As the electrode surface will, in general, be electrically charged, there will be a surplus of ionic charge with opposite sign in the electrolyte phase in a layer of a certain thickness. The distribution of jons in the electrical double layer so formed is usually described by the Gouy— Chapman—Stern theory [20], which essentially considers the electrostatic interaction between the smeared-out charge on the surface and the positive and negative ions (non-specific adsorption). An extension to this theory is necessary when ions have a more specific interaction with the electrode, i.e. when there is specific adsorption of ions. 

C6 A. Klamt and V. Jonas, Treatment of the outlying charge in continuum solvation models, J. Chem. Phys., 105 (1996) 9972-9981. 

Fig. 5.15(a) Illustration of the sample structure used in sweep-out experiments, (b) Example of the sweep-out current pulse for n-type a-Si H. Qq is the displacement charge of the sample electrodes, and Qg is the sweep-out charge (Street 1989). 

The situation here does have a fairly large shadow on it because of the use of the expression (3.120) in ic. It will be seen (Section 3.14) that, at concentrations as high as 1 N, there are some fundamental difficulties for the ionic-cloud model on which this ic expression of Eq. (3.120) was based (the ionic atmosphere can no longer be considered a continuum of smoothed-out charge). It is clear that when the necessary mathematics can be done, there will be an improvement on the VF expression, and one will hope to get it more correct than it now is. Because of this shadow, a comparison of Eq. (3.130) with experiment to test the validity of the model for removing solvent molecules to the ions sheathes should be done a little with tongue in cheek. 

Spreading out charge by the overlap of an empty p orbital with an adjacent a bond is called hyperconjugation. 

But, by allocating the electrons to the localised MO s, we can describe, without mathematical analysis, the fact that two electrons with the same spin tend at any instant to occupy different regions of space. Different electron pairs have, in fact, an interaction energy which can be closely estimated by regarding each as a smeared-out charge. 

A. 15.5 Three of the following. (1) A central reference ion of a specific charge can be represented as a point charge. (2) This central ion is surrounded by a cloud of smeared-out charge contributed by the participation of all of the other ions in solution. (3) The electrostatic potential field in the solution can be described by an equation that combines and linearizes the Poisson and Boltzmann equations. (4) No ion — ion interactions except the electrostatic interaction given by a l/z dependence are to be considered (i.e., dispersion forces and ion - dipole forces are to be excluded). (5) The solvent simply provides a dielectric medium, and the ion — solvent interactions are to be ignored, so that the bulk permittivity of the solvent can be used. 

Ionic cloud and adjacent charge. 244 catching up with moving ions, 507 and chemical potential changes, 250 egg shaped, 508 electrojhoretic effect, 509 its potential, 250 a smeared out charge, 234 Ionic cloud theory, a prelude. 232 loiric crystals, dissolution, 36 Ionic current density, electric field, a hyperbolic relation, -168... 

Although the above is a description in terms of discrete charges for the central reference ion, the ionic atmosphere is treated as though there were no discrete charges in it, and it behaved as a smeared out charge cloud. ... 

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