Low-temperature Raman spectra of L-histidine crystal
arXiv:1304.7692 · doi:10.1007/s13538-013-0132-3
Abstract
We present a Raman spectroscopy investigation of the vibrational properties of L-histidine crystals at low temperatures. The temperature dependence of the spectra show discontinuities at 165 K, which we identify with modifications in the bonds associated to both the NH3+ and CO2- motifs indicative of a conformational phase transition that changes the intermolecular bonds. Additional evidence of such a phase transition was provided by differential scanning calorimetry measurements, which identified an enthalpic anomaly at ~165 K.
18 pages, 5 figures and 1 table, Brazilian Journal of Physics, 2013