Ricerc@Sapienza

The assignment of the absolute configuration (AC) of two conformational flexible organic molecules by
means of TD-DFT simulation of the electronic circular dichroism (ECD) spectra is presented. The factors
leading to a reliable assignment were evaluated in the various steps of the process. The effects of
different functionals and basis sets in the geometry optimization step is very limited in terms of the
resulting optimized geometries, whereas the inclusion of the solvent in the calculations has a much
larger effect on the correct evaluation of the conformational ratio. B3LYP and M06-2x were found to be
the most accurate functionals for geometry optimization. CAM-B3LYP and uB97X-D provided the best
results in the TD-DFT simulations.