SOLVENT EFFECTS .1. THE MEDIATION OF ELECTROSTATIC EFFECTS BY SOLVENTS

Solvent effects on conformational equilibria, rotational barriers, charge distributions, and molecular properties of ionic and neutral dipolar molecules have been investigated by high-level ab initio reaction field theory. The calculated solvent effects on the conformational equilibrium of 1,2-dichloroethane and furfural are in good agreement with experiments. The rotational barriers for the interconversion of the Z and E isomers of (2-nitrovinyl)amine in solution are also reasonably reproduced by reaction field theory. In the presence of a solvent reaction field, the geometry, energy, and charge distribution of methoxide anion are found to alter significantly. For the application of reaction field theory to neutral dipolar species, we have examined the solvent effect of two simple 1,3-dipoles, diazomethane and acetonitrile oxide. Dielectric medium appears to have significant different effects on the calculated electronic structure of these two compounds. In this paper, we also have formulated a correlated version of the Onsager reaction field method for studying solvent effects. In some cases, the use of correlated wave functions is found to produce more reliable results.