Dispersive interactions, charge transfer

Abbreviations are in parentheses. The dd interactions are also known as Keesom interactions di interactions are also known as Debye interactions ii interactions are also known as London or dispersion interactions. Collectively, dd, di and ii interactions are known as van der Waals interactions. Charge transfer interactions are also known as donor-acceptor interactions. 

The SMO-LMBPT method conveniently uses the transferability of the intracorrelated (one-body) parts of the monomers. This holds, according to our previous results [3-10], at the second (MP2), third (MP3) and fourth (MP4) level of correlation, respectively. The two-body terms (both dispersion and charge-transfer components) have also been already discussed for several systems [3-5]. A transferable property of the two-body interaction energy is valid in the studied He- and Ne-clusters, too [6]. In this work we focus also on the three-body effects which can be calculated in a rather straightforward way using the SMO-LMBPT formalism. 

The idea of solvent polarity refers not to bonds, nor to molecules, but to the solvent as an assembly of molecules. Qualitatively, polar solvents promote the separation of solute moieties with unlike charges and they make it possible for solute moieties with like charges to approach each other more closely. Polarity affects the solvent s overall solvation capability (solvation power) for solutes. The polarity depends on the action of all possible, nonspecific and specific, intermolecular interactions between solute ions or molecules and solvent molecules. It covers electrostatic, directional, inductive, dispersion, and charge-transfer forces, as well as hydrogen-bonding forces, but excludes interactions leading to definite chemical alterations of the ions or molecules of the solute. 

The structure of yint depends, in general, on the nature of the solute-solvent interaction considered by the solvation model. As already noted in the contribution by Tomasi, a good solvation model must describe in a balanced way all the four fundamental components of the solute-solvent interaction electrostatic, dispersion, repulsion, charge transfer. However, we limit our exposition to the electrostatic components, this being components of central relevance, also for historical reason, for the development of QM continuum models. This is not a severe limitation. As a matter of fact, the QM problem associated with the solute-solvent electrostatic component defines a general framework in which all the other solute-solvent interaction components may be easily collocated, without altering the nature of the QM problem [5],... 

Interactions The complexation is based on a combination of several intermolecular interactions depending on the solvent and the nature of the host and guest steric fit, van der Waals interactions, dispersive forces, dipole-dipole interactions, charge-transfer... 

Fortunately, there are a number of theoretical, statistical and empirical reasons to believe that Lewis basicity (affinity) depends on a limited number of factors. From the quantum chemical point of view, the acid/base interaction energy can be partitioned into five terms (electrostatic, dispersion, polarization, charge transfer and exchange-repulsion). By a principal component analysis [184], 99% of the variance of an afflnity/basicity data matrix can be explained by three factors, the first two being by far the most important. A number of experimental affinity and basicity scales, and of spectroscopic scales of basicity, can be correlated by two parameters, using the EC or equations, or three quantum chemical descriptors of basicity [197]. However, these statistical and empirical approaches are limited to systems where steric effects and tt back-bonding are not important. 

B. de Courcy, J. P. Dognon, C. Clavaguera, N. Gresh, and J. P. Piquemal, Int. J. Quant. Chem., 111(6), 1213-1221 (2011). Interactions within the Alcohol Dehydrogenase Zn(II)-Metalloenzyme Active Site Interplay between Subvalence, Electron Correla-tion/Dispersion, and Charge Transfer/Induction Effects. 

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