Effect of pressure on crystalline L- and DL-serine: revisited by a combined single-crystal X-ray diffraction at a laboratory source and polarized Raman spectroscopy study

Information on the effect of pressure on hydrogen bonds, which could be derived from single-crystal X-ray diffraction at a laboratory source and polarized Raman spectroscopy, has been compared. l-Serine and DL-serine were selected for this case study. The role of hydrogen bonds in pressure-induced phase transitions in the first system and in the structural stability of the second one are discussed. Non-monotonic distortion of selected hydrogen bonds in the pressure range below similar to 1-2 GPa, a change in the compression mechanism at similar to 2-3 GPa, and the evidence of formation of bifurcated N-H center dot center dot center dot O hydrogen bonds in DL-serine at similar to 3-4 GPa are considered.