Calculations of the infrared and vibrational circular dichroism spectra of ethanol and its deuterated isotopomers

The scaled quantum mechanical force field method together with the Stephens formalism for the evaluation of rotational strengths has been used to calculate infrared and vibrational circular dichroism (VCD) spectra of ethanol and its deuterated isotopomers. For the IR spectra, agreement between the calculated and experimental spectra is extremely good; the root-mean-square deviation between the calculated and experimental frequencies for all 12 isotopomers is 15 cm{sup {minus}1}. The calculated VCD spectra are also in good agreement with the experimental ones when the evaluation of the rotational strengths is carried out using the distributed origin gauge. Both the IR and VCD results confirm the earlier conjecture that the gauche conformer predominates over the trans, even though the trans has a slightly lower SCF energy.