High pressure study of pentaerythritol: A synchrotron infrared study

High pressure and low-temperature polymorphism in cyclopentanol

“…Therefore, the decrease in the wavenumber of the O-H stretching modes with pressure suggests that the compression strengthens the hydrogen bonding. [12] Therefore, these results indicate both the low-temperature phases and high pressure phases are characterized by the formation of hydrogen-bonded molecular chains.…”

“…[5] It is reported that compression can cause significant variations in the relative strength of the hydrogen bond, which played an important role in its high pressure structure. [12,19] Figure 7 represents the Raman spectra of cyclopentanol under different pressures in the region of wavenumbers 2500 to 3450 cm −1 . Among this spectral region, the broad band at around 3100-3450 cm −1 is attributed to O-H stretching vibrations.…”

“…As is well known, Raman and infrared spectroscopies are two powerful in situ observations, providing interesting insights into the nature of hydrogen bonding, and dynamics of phase transitions and conformational changes. [12,13] Nevertheless, currently, few Raman and infrared researches on pressure-induced phase transition of cyclopentanol have been reported.…”

Raman study of plastic crystal phase of cyclooctanol under high pressure with different compression rate

“…It has been reported that the low-frequency part of the OeH stretching band at 3200 cm À1 is caused by the vibrations of OeH groups with strong hydrogen bonds, while the region of the stretching OeH band in the vicinity of 3420 cm À1 is due to the vibrations of OeH oscillators with weak hydrogen bonds. Therefore, the decrease in the frequency of the OeH stretching modes suggests that the hydrogen bonding is strengthened during compression [7,15]. Therefore, it could be inferred that hydrogen bond plays an important role in the phase transitions and the high pressure phases is characterized by the formation of hydrogen-bonded molecular chains.…”

“…However, the information about the dynamics of phase transitions, molecular structure and conformational change has not been reported. It is well known that, Raman spectroscopy is one crucial tool, in situ observing and providing interesting insights into the dynamics of phase transitions and conformational changes [7,8]. Nevertheless, currently, few Raman researches have been reported on the pressure-induced phase transition of cyclooctanol.…”