Modeling chiroptical properties of molecules in solution

PHYS 562

Parag Mukhopadhyay, pm30@duke.edu1, Gérard Zuber, gzuber@duke.edu1, Michael-Rock Goldsmith1, David N. Beratan, david.beratan@duke.edu1, and Peter Wipf, pwipf@pitt.edu2. (1) Department of Chemistry, Duke University, Paul M. Gross Chemical Laboratory, Box 90349, Durham, NC 27708, (2) Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260
A long-standing challenge in molecular stereochemistry is to assess the contributions of the solvent surrounding a chiral molecule to the optical rotation (OR) of the system. The observed specific rotation angles of chiral molecules are strongly influenced by solvent-solute interactions. For example, methyloxirane has a positive OR in water and a negative OR in benzene. Our study is the first that investigates solvent effects on the OR using explicit solvent models. As a test case, we studied the solvent dependence of the OR spectra of methyloxirane using molecular dynamics simulations and time-dependent density functional theory methods. We show that for propylene oxide in water, it is essential to include explicit solute-solvent interactions in the theoretical analysis to describe the observed OR. In contrast, for propylene oxide in benzene, the chiral solvent ordering of benzene around propylene oxide dominates the OR.

General Posters
7:30 PM-10:00 PM, Wednesday, March 28, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Physical Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007