Electrostatic Coulombic effects

The essential realization in this spontaneous ordering process is the importance of noncovalent bonding interaction between molecules, that is, supramolecular chemistry. These conformation-specific interactions are governed by weak forces including hydrogen bonding, metal coordination, van der Waals forces, pi-pi interactions, and electrostatic Coulombic effects. The cooperative action of multiple noncovalent interaction forces is precisely the path nature takes to produce shape and form. 

The extent to which ions, etc. adsorb or experience an electrostatic ( coulombic ) attraction with the surface of an electrode is determined by the material from which the electrode is made (the substrate), the chemical nature of the materials adsorbed (the adsorbate) and the potential of the electrode to which they adhere. Adsorption is not a static process, but is dynamic, and so ions etc. stick to the electrode (adsorb) and leave its surface (desorb) all the time. At equilibrium, the rate of adsorption is the same as the rate of desorption, thus ensuring that the fraction of the electrode surface covered with adsorbed material is constant. The double-layer is important because faradaic charge - the useful component of the overall charge - represents the passage of electrons through the double-layer to effect redox changes to the material in solution. 

Although the interactions of charged, dipolar or polarizable groups have been investigated for various purposes, they have not often been utilized in the context of stereoselectivity. In fact, when coulombic effects were considered in the SN2 or E2 processes, their role was regarded as unimportant (Ingold, 1953 Cristol, et al., 1951). In view of the substantial electrostatic (field) effects estimated for polar substituents on the pA s of carboxylic acids (Tanford, 1958), metal-ion coordination (Basolo and Pearson, 1967), etc., it will be interesting to see what effects there may be on SS. 

Another Coulombic energy approach for the calculation of electrostatic solvent effects on reactions between dipolar molecules was made by Amis [12, 21, 244]. He related the rate constant to the energy of activation by the well-known Arrhenius equation k = A exp —E /RT). It is assumed that the effect of the relative permittivity on the rate is given by Eq. (5-90) ... 

Because the anomeric effect had been discussed at that time in terms of electrostatic interactions (cf. Section III.A.l), Wolfe et al. further separated the electron-electron repulsion term into coulombic F " and exchange F terms. They assumed that F " is the quantum mechanical counterpart of the classical electrostatic coulombic repulsions whose significance might thus be estimated. 

Intermolecular interaction A collective term for the attractive (and repulsive) forces that control the association of two or more molecular entities. Intermolecular interactions include electrostatic (Coulombic) forces, van der Waals forces including dispersion (London) forces, hydrogen bonding interactions, Lewis acid—Lewis base interactions, electron-donor—electron-acceptor interactions, and the hydrophobic (solvophobic) effect. The same types of interactions can also occur between parts of the same molecular entity (intramolecular interactions). Although some interactions are weak relative to a covalent bond, others are not. The term includes a range of bonding characters from predominantly covalent, polar covalent, or ionic. 

This deformation is mainly due to a Coulombic effect, arising from the electrostatic interactions among the electrode free charges. The stress of the Coulomb force acting between the electrode free charges is responsible for... 

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