Electrostatic/ionic

Indirect electronic effects occur over a longer range than direct effects, requiring no orbital overlap. Electrostatic ionic interactions fall partly within this category, since the... 

The simplest effect of pure electrostatic ionic adsorption on electrode reaction rates of ions is the Frumkin double layer effect already been discussed in Sect. 3.5. 

Figure 7. The Kamlet—Taft n parameter vs. solvent number density. Select molecular solvents possess little or no capacity for hydrogen bonding, and their interactions are controlled by electrostatics. Ionic liquids are categorized based on whether they possess a cyclic cation or an alkylammonium cation. A wide range of anions are employed in both categories, and no attempt is made to restrict specific interactions. Taken from Ref. [239]...

Here we set out some of the experimental evidence, which forces us to reexamine the electrostatic, ionic approach inherent in CFT. 

AB in the gas phase or in an inert solvent, and E and C are parameters calculated from experimental data. is a measure of the capacity for electrostatic (ionic) interactions and C is a measure of the... 

One phenomenon not well accounted for by other approaches is seen in Table 6-8. It shows a series of four acids and five bases in which both E and C increase. In most descriptions of bonding, as electrostatic (ionic) bonding increases, covalent bonding decreases, but these data show both increasing at the same time. Drago argued that this means that the E and C approach explains acid-base adduct formation better than the HSAB theory described earlier. 

The d electrons in Ga shield the outer electrons, so they are held less tightly. This results in less electrostatic attraction for the outer electrons and those of the p5nidine, which makes them less likely to form either an electrostatic (ionic) or covalent hond. 

The crystal field theory (CFT) was developed for crystalline solids by the physicist Hans Bethe in 1929. The model takes into account the distance separating the positively and negatively charged ions and treats the ions simply as point charges with the attractive and repulsive interactions between them as purely electrostatic/ionic... 

Figure 3.5 Plot of the association constant of some 1 1 metal cation-hydroxy complexes at zero ionic strength (see Chap. 4) versus the electrostatic function luZon/irti + Toh). where the association reaction is written Af + OH"=A/OH " , and z and r are the charge and radius in nanometers (nm) or angstroms (A) (1 nm = 1 A) of cation M and OH ( oh = 1-40 nm). Cation radii are from Shannon and Prewitt (1969), log values from Baes and Mesmer (1981). The slope of the straight line suggests the contribution of electrostatic (ionic) bonding to the stability of the complexes. The extent to which species plot above this line presumably reflects the increased contribution of covalency to their stabilities.

The interatomic forces between atoms result in an atomic aggregate with sufficient stability to form chemical bonds within a molecule. According to the valence bond theory, a chemical bond is formed when an electron in one atomic orbital pairs its spin with that of an electron supplied by another atomic orbital, these electrons are then shared between two or more atoms so that the discrete nature of the atom is lost. Three main types of chemical bond are considered covalent, electrostatic (ionic) and metallic bonds. 

Lacroix, E., Viguera, A.R., Serrano, L. Elucidating the folding problem of a-helices local motifs, long-range electrostatics, ionic-strength dependence and prediction of NMR parameters, J. Mol. Biol. 1998,284,173-91. 

We shall consider in this section those solvents having Sr < 12. At this low dielectric constant, electrostatic ionic interactions are very large and often triple ion formation is encountered. The conductance has been observed to pass through a minimum with concentration, indicating the formation of triple ions, for i 4N-p-toluenesulphonates in triaryl phos-phides, for LiCl and bivalent chlorides in tetrahydrofuran(THF), and for MeEtgNI in... 

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