Raman spectroscopic study of cyclopentane at high pressure.
The behavior of cyclopentane with pressure has been investigated to 21.5 GPa using Raman spectroscopy. Various phases were observed with pressure which included liquid, two plastic, and one true crystalline phases of cyclopentane during compression and decompression sequences. Optimized molecular structure and Raman and IR vibrational spectra of the most stable puckered-ring conformation of the cyclopentane molecule were also computed using density functional theory methods. The theoretically calculated values as well as the experimentally determined pressure dependencies of spectral bands are in very good agreement with the low temperature measurements and previous mode assignments. The phase diagram of cyclopentane was analyzed with respect to pressure-induced alterations in Raman spectra across the phase boundaries. The various forms of "frozen-in" conformations in phase III are suggested to explain previous results related to existence of a "new" phase between plastic crystalline phase II and monoclinic phase III in solid cyclopentane.
Tkachev
Sergey N
SN
Department of Physics and Astronomy, and High Pressure Science and Engineering Center, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, USA.
Pravica
Michael
M
Kim
Eunja
E
Weck
Philippe F
PF