Vibrational circular dichroism and absolute configuration of chiral sulfoxides: tert-butyl methyl sulfoxide

Mid-infrared vibrational unpolarised absorption and vibrational circular di chroism (VCD) spectra of CCl4 solutions of tert-butyl methyl sulfoxide (1) are reported. The spectra are compared to ab initio density functional theo ry (DFT) calculations carried out using two functionals. B3PW91 and B3LYP, and two basis sets, 6-31G* and TZ2P. The VCD spectra are calculated using G auge-invariant atomic orbitals (GIAOs). The analysis of the VCD spectrum co nfirms the R(-)/S(+) absolute configuration of 1. The advantages and disadv antages of VCD spectroscopy in determining the absolute configurations of c hiral sulfoxides are discussed.