Charge displacement processes

Obviously, in symmetrical systems, all atoms which are symmetrically related to the atom m should also be excluded from N, if the symmetry is to be preserved in the charge displacement process. 

The mechanism of these displacement processes presumably involves a metal-assisted addition-elimination reaction, in which the metal ion stabilises the charge in the intermediate (Fig. 8-33). A number of useful synthetic applications of this methodology are... 

Equations (5.83) and (5.84) and the curves in Fig. 5.12 indicate that both peak current and potential of the CV curves change with the scan rate, a feature which is not observed for the peak potential of reversible processes (see Eq. (5.57)). However, the experimental evidence that for a given system the potential peak of the cathodic CV curves shifts to more negative values with increasing scan rate should be used with caution when assigning a non-reversible behavior to the system since, similar displacements can be observed for Nemstian systems when the ohmic drop has an important effect (see Fig. 5.11). Thus, the shift of the CV peak potential with the scan rate is not always a guarantee of a non-reversible charge transfer process. 

One concludes from this analysis that the rigid IDM provide an adequate reference frame for describing both external and internal CT processes in a reasonably compact form. However, carrying no information whatever about the reactant interaction, they are - by definition - one-reactant concepts, and therefore may not constitute the optimum collective charge displacement coordinates for reactive systems. In Sections 5.2 and 5.3 we extend this search into... 

This way of generating the EDM (-> IDM) collective modes guarantees their one-to-one correspondence to the respective IDM of reactants and, as such, may provide an alternative, convenient framework for describing the CT processes. Like the IDM, such localized EDM preserve the memory of the reactant interaction in M + and should lead to substantial hardness decoupling. This expectation is due to their resemblance to the PNM (IDM) of reactants, for which the diagonal (reactant) blocks of the relevant hardness matrix are exactly diagonal. Thus, with no external hardness interaction between the A and B subsets of EDM, it comes as no surprise that these collective, delocalized charge-displacement modes also bear some similarity to the PNM of M as a whole. 

Their eigenvectors, which we call the inter-reactant modes (IRM), provide yet another collective charge displacement reference frame, which can be used to describe the CT processes (internal or external) in a general reactive system... 

Figure 3. Schematic illustration of the role of surface charge in the oil displacement process.

---