Abstract
<jats:p>This work explores the effect of explicit solvent molecules on the computed sign and magnitude of Rayleigh optical activity (RayOA) of (S)-methyloxirane. The solvents investigated are water, methanol, benzene and acetonitrile. Methyloxirane is infamous for the sign reversal of its specific rotation (SR) depending on the polarity of the solvent used for measurements. SR depends directly on the trace of electric dipole-magnetic dipole (EDMD) tensor. RayOA however depends on the products of EDMD and electric dipole-electric dipole (EDED) tensor elements, in addition to the products of EDED and electric dipole-electric quadrupole (EDQD) tensor elements. Since RayOA and SR have differing phenomenological dependence on the EDMD tensor, it is worth exploring if RayOA has any less solvent dependence than SR is known to have. For this reason, current RayOA work also reports parallel investigations on SR under identical conditions. To accomplish this, microsolvation calculations were performed with (S)-methyloxirane in explicit solvent (water, methanol, benzene, or acetonitrile) with varying number of solvent molecules. The sign of predicted RayOA is found to depend on the nature of the solvent used, however it is more consistent than SR as the number of explicit solvent molecules is varied. It also appears that RayOA may be less error-prone than SR in terms of theoretical predictions using a limited number of explicit solvent molecules. This positive prognosis calls for solvent dependent experimental RayOA measurements on computationally tractable chiral compounds.</jats:p>