Density functional calculations of the frequency-dependent optical rotation: Comparison of theory and experiment for the gas phase

Abstract

The optical rotations (OR) of five chiral organic molecules have been calculated by time-dependent density functional response theory (TDDFT) employing four different density functionals. The results are compared with experimental gas phase data in order to explore the inherent accuracy of the functionals. The theoretical results obtained with the BHLYP hybrid functional including 50% “exact” Hartree-Fock exchange compare very well with the experimental data and also better with those derived from the gas-phase than from solution. Non-hybrid functionals show a tendency to overestimate the OR. The anomalous behavior of the methyloxirane molecule which shows sign changes with solvent and excitation frequency is discussed.