Induction, electrostatic

There are tliree important varieties of long-range forces electrostatic, induction and dispersion. Electrostatic forces are due to classical Coulombic interactions between the static charge distributions of the two molecules. They are strictly pairwise additive, highly anisotropic, and can be either repulsive or attractive. 

Long-range forces are most conveniently expressed as a power series in Mr, the reciprocal of the intemiolecular distance. This series is called the multipole expansion. It is so connnon to use the multipole expansion that the electrostatic, mduction and dispersion energies are referred to as non-expanded if the expansion is not used. In early work it was noted that the multipole expansion did not converge in a conventional way and doubt was cast upon its use in the description of long-range electrostatic, induction and dispersion interactions. However, it is now established [8, 9, 10, H, 12 and 13] that the series is asymptotic in Poincare s sense. The interaction energy can be written as... 

Absorption, metaboHsm, and biological activities of organic compounds are influenced by molecular interactions with asymmetric biomolecules. These interactions, which involve hydrophobic, electrostatic, inductive, dipole—dipole, hydrogen bonding, van der Waals forces, steric hindrance, and inclusion complex formation give rise to enantioselective differentiation (1,2). Within a series of similar stmctures, substantial differences in biological effects, molecular mechanism of action, distribution, or metaboHc events may be observed. Eor example, (R)-carvone [6485-40-1] (1) has the odor of spearrnint whereas (5)-carvone [2244-16-8] (2) has the odor of caraway (3,4). 

Electrostatic-induction separation number Dimensionless Dimensionless ... 

In a solution of a solute in a solvent there can exist noncovalent intermolecular interactions of solvent-solvent, solvent-solute, and solute—solute pairs. The noncovalent attractive forces are of three types, namely, electrostatic, induction, and dispersion forces. We speak of forces, but physical theories make use of intermolecular energies. Let V(r) be the potential energy of interaction of two particles and F(r) be the force of interaction, where r is the interparticle distance of separation. Then these quantities are related by... 

Substituents may change the reactivity of a molecule through steric or electronic effects or both. The latter include electrostatic, inductive, and resonance effects. The exploration to learn whether an LFER can be established may be very helpful in assessing the contributions from these sources and may thus provide an informative probe of the mechanism, particularly as regards electronic effects. The following items illustrate some uses of LFER correlations or deviations from them ... 

Cabral BJC, Rivail JL, Bigot B (1987) A Monte-Carlo simulation study of a polarizable liquid -influence of the electrostatic induction on its thermodynamic and structural-properties. J Chem Phys... 

Robinson s theory was one of electron displacements propagated by electrostatic induction along the length of a carbon chain. As a hydrogen atom at one end of a carbon chain becomes a weakly held proton, electron charge drifts... 

Indeed, it has been shown26 that in addition to the delocalization factor, there are several other contributions to the magnitude of Kcom such as structural, electrostatic, inductive and magnetic factors so one must be cautious in attributing electrochemically calculated Mcora values only to charge delocalization. 

The total stabilization energy of a cluster rarely exceeds 25 kcal mol , i.e., a small fraction of a strong covalent bond energy (ca. 100 kcal mol ). Its partitioning into electrostatic, induction, and dispersion terms differs from cluster to cluster. In some cases, one particular energy term is dominant. More typically, many attractive terms contribute to the overall stabilization of non-covalent clusters, as it often happens to hydrogen-bonded complexes. Nevertheless, the electrostatic interaction plays a dominant role, and in the case of polar subsystems. 

The polarization of a chemical bond caused by the polarization of an adjacent or nearby bond. The inductive effect depends only on the nature of the bonds and is transmitted through a chain of atoms by electrostatic induction. See also Field Effect... 

M. O. Bulanin. Electrostatic induction in van der Waals complexes. In J. Szudy, ed., Spectral Line Shapes 5, p. 597, Ossolineum, Warsaw, 1989. 

In Sec. V,3 we dealt with the adsorption of ions on metallic surfaces as the problem of the polarization of an ideally polarizable structure by the ion. Dielectrics have a more restricted polarizability, the polarization resulting in the shifting of the electrons in the atoms or in groups of atoms of the dielectric to which they belong or in the mutual shifting of ions as well (34)- Instead of Eq. (16), which holds for an adsorbent of ideal polarizability, we obtain for the adsorption energy contribution due to the electrostatic induction of a dielectric ... 

Here, s"(co) is the image part of the dielectric permittivity e(m), and AD(7) is the difference of the values of electrostatic induction in the initial and final states this difference is caused by the electron transfer ... 

A. di Matteo, S. M. Todd, G. GottareUi, G. Solladie, V. E. Williams and R. P. Lemieux, Correlation between molecular structure and helicity of induced chiral nematics in terms of short-range and electrostatic-induction interactions. The case of chiral biphenyls, J. Am. Chem. Soc., 123 (2001) 7842-7851. 

Depending on the nature of interacting molecules, some interactions may be negligible or equal to zero. Direct electrostatic, induction and dispersion interactions are combined in a general concept of van der Waals nonspecific interactions which are not related to the electron shell overlap. 

The antisymmetrizing operator also affects the form of the electrostatic, induction, and dispersion energies. For example, in the case of neutral, spherically symmetric systems, the electrostatic and induction energies (which vanish in the limit of negligible orbital overlap) display a dependence on r similar to the first-order exchange energy,67... 

Solute-solvent interactions in dithiole-thiones and -ones are attributed to localized electrostatic induction. The strength of the hetero-association complexes is determined by the distribution of the electric field around the carbonyl or thiocarbonyl group (72HCA213). 

Although the spherical form of the multipole expansion is definitely superior if the orientational dependence of the electrostatic, induction, or dispersion energies is of interest, the Cartesian form171-174 may be useful. Mutual transformations between the spherical and Cartesian forms of the multipole moment and (hyper)polarizability tensors have been derived by Gray and Lo175. The symmetry-adaptation of the Cartesian tensors of quadrupole, octupole, and hexadecapole moments to all 51 point groups can be found in Ref. (176) while the symmetry-adaptation of the Cartesian tensors of multipole (hyper)polarizabilities to simple point groups has been considered in Refs. (172-175). 

Since the single-center multipole expansion of the interaction energy is divergent, one could use a kind of multicenter expansion. One can hope that the multipole expansion will provide better results if multipole moments and polarizabilities localized at various points of a molecule are used instead of global multipole moments and polarizabilities. This idea forms the basis of the so-called distributed multipole analysis of the electrostatic, induction, and dispersion interactions between molecules187 195. 

The electrostatic, induction, and dispersion terms can be expanded in a convergent series closely related to the multipole expansion, but fully accounting for the charge-overlap effects, the so-called bipolar expansion introduced by Buehler and Hirschfelder199,200. In the local coordinate systems with the origins located at the centers of masses of the monomers A and B, separated by the distance R, and with their x and y axes parallel and aligned along the z axes, the distance between two particles in space can be expressed as follows,... 

Fig. 44 Schematic diagram of the signal pathway in the non-contact mode SFM for imaging of surface charge through electrostatic induction...

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