Investigation of the stereo structures of chiral molecules using vibrational circular dichroism, optical rotation, and density functional theory
The stereo structures of variety chiral molecules were studied by vibrational circular dichroism (VCD), optical rotation (OR), and density functional theory in this dissertation. The error ranges in the density functional theory predicted values for VCD and OR were established by studying chiral molecules: (R)-3-chlorobutyne, (S)-3-butyn-2-ol, and (R)-3-methylcyclopentanone. The absolute configurations of chiral substituted propanoic acid herbicides and glutamic acids homologue compounds were successfully determined by the combination of experimental VCD, OR, and density functional theory calculations. The correct molecular model is essential for absolute configuration determination. Some unconventional chiral molecules, such as helical polymers and fullerene, were also studied by this method. The handedness of their helix was assigned. This research shows that the combination of experimental chiroptical techniques and density functional theory calculations is a powerful tool in studying the stereo structures, which includes both the absolute configuration and conformations, of chiral molecules.