CAM-B3LYP optical rotations at different wavelengths: Comparison with CCSD results

A hierarchical sequence of basis sets along with one long‐range corrected functional (CAM‐B3LYP) were used to calculate electronic optical rotations (OR) at three wavelengths (355.0, 589.3, and 633.0 nm) of 14 rigid chiral molecules whose experimental values are available in the literature. As the results showed to be sensitive to the basis set quality, complete basis set limits were estimated. Special attention was given to five particularly difficult compounds. In these cases, one verifies that vibrational corrections (taken from the literature) must be added to the CAM‐B3LYP equilibrium OR to correct signs. In general, the complete basis set limits reported in this work are in good agreement with the experimental data and with those obtained at a higher level of theory. For some compounds, solvent effects are taken into account by means of the polarizable continuum model. For the solvated systems, the dependence between OR and cavity size is also examined. © 2015 Wiley Periodicals, Inc. An established approach to deduce the absolute stereochemistry in molecules is to compare theoretical and experimental specific optical rotations. Fourteen rigid chiral molecules were used as a test set to determine the accuracy of optical rotations calculated using the CAM‐B3LYP density functional. The results were sensitive to the basis set quality. CAM‐B3LYP is proposed as an excellent compromise between accuracy and computational cost in determining absolute configurations of conformationally rigid chiral molecules.