Solvent effects self consistent reaction field

Keywords Solvent Effects, Self-consistent Reaction Field, Continuum, Cavity, Polarizable Contin-... 

Fig. 2.2 Self-Consistent Reaction Field (SCRF) model for the inclusion of solvent effects in semi-empirical calculations. The solvent is represented as an isotropic, polarizable continuum of macroscopic dielectric e. The solute occupies a spherical cavity of radius ru, and has a dipole moment of p,o. The molecular dipole induces an opposing dipole in the solvent medium, the magnitude of which is dependent on e.

Tapia, O. and O. Goscinski. 1975. Self-consistent reaction field theory of solvent effects. Mol. Phys. 29, 1653. 

Self-consistent reaction field (SCRF) models are the most efficient way to include condensed-phase effects into quantum mechanical calculations [8-11]. This is accomplished by using SCRF approach for the electrostatic component. By design, it considers only one physical effect accompanying the insertion of a solute in a solvent, namely, the bulk polarization of the solvent by the mean field of the solute. This approach efficiently takes into account the long range solute-solvent electrostatic interaction and effect of solvent polarization. However, by design, this model cannot describe local solute-solvent interactions. 

Solvation effects on the conformation of esters of three /i-snbstituted 1-phenyletha-nols with 2-flnoro-2-phenyl acetic acid (FCDA) were studied both experimentally (in five solvents ranging from CDCb to DMSO) and quantum mechanically. Semi-empiri-cal (AMI of MJS Dewar and PM3 of JJP Stewart) and ab initio (RHF/3-21 G) calculations were undertaken. Energy maps for the conformers of the esters as a function of the dihedral angles alpha (F-C-alpha acid-C=0) and beta (CO-O-C-alcohol-H) were obtained. Solvent effect calculations, through the self-consistent reaction field on the most stable conformers, were also carried out (Hamman et al., 1996). 

Organometallic systems such as porphyrines have been investigated because of the possibility to fine tune their response by functionalization[105-107]. Systems of increased the dimensionality have been of particular interest [108-111], Concomitant to the large effort to establish useful structure-to-properties relationships, considerable effort has now been put to investigate the environmental effects on TPA[112-114], For example, the solvent effect has been studied for a small linear push-pull chromophore using a self-consistent reaction field (homogeneous solvation) method employing a spherical cavity and an internal force field (IFF) method[l 12] in another study the polarizable continuum model has been employed to calculate the relevant quantities to obtain the TPA cross-section in the limit of a two-state model[113] Woo et al. made a critical study of experimental comparison of TPA cross-sections in different solvents[114]. 

Here we give an overview of the current status and perspectives of theoretical treatments of solvent effects based on continuum solvation models where the solute is treated quantum mechanically. It is worth noting that our aim is not to give a detailed description of the physical and mathematical formalisms that underlie the different quantum mechanical self-consistent reaction field (QM-SCRF) models, since these issues have been covered in other contributions to the book. Rather, our goal is to illustrate the features that have contributed to make QM-SCRF continuum methods successful and to discuss their reliability for the study of chemical reactivity in solution. 

O. Tapia, /. Mol. Struct. (THEOCHEM), 226, 59 (1991). On the Theory of Solvent-Effect Representation. I. A Generalized Self-Consistent Reaction Field Theory. 

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