| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1410043 | Journal of Molecular Structure | 2011 | 7 Pages |
Since the introduction of ultra-fast laser techniques for the generation and detection of broadband terahertz pulses, terahertz time-domain spectroscopy has become a versatile tool for vibrational spectroscopy of molecular systems in the far-infrared. Due to their highly collective and delocalized character vibrational modes in this part of the spectrum are highly sensitive to molecular structure and arrangement within a molecular crystal. Here we utilize this sensitivity to differentiate between the enantiopure amino acid l-cysteine and its racemic crystalline dl-form. Using terahertz time-domain spectroscopy we are able to observe temperature induced solid-state phase transitions in polycrystalline dl-cysteine, as well as in polycrystalline benzoic acid. The dynamics of the transitions is studied by tracing the temperature dependency of spectral features that are assigned to certain conformational phases.
► Terahertz time-domain spectroscopy for vibrational spectroscopy of molecular systems in the far-infrared. ► Terahertz spectra are highly sensitive to molecular structure and arrangement. ► It is possible to differentiate between enantiopure l-cysteine and its racemic dl-form. ► Temperature induced solid-state phase transitions are investigated in dl-cysteine and in benzoic acid crystals.
