High-pressure Raman study of Terephthalonitrile.
The in situ high-pressure Raman spectra of Terephthalonitrile (TPN) have been investigated from ambient to 12.6GPa at room temperature. All the fundamental vibrational modes of TPN at ambient were assigned based on the first-principle calculations. A detailed Raman spectroscopy analysis revealed that TPN underwent a phase transition at ~5.3GPa. The frequencies of the TPN Raman peaks increase with increasing the pressure which can be attributed to the reduction in the interatomic distances and the escalation of effective force constants. The intensity of the C-C-C ring-out-plane deformation mode increases gradually as the frequency remains almost constant during the compression which can be explained by the existence of π-π interactions in TPN molecules. Additionally, the pressure-induced structural changes of TPN on the Fermi resonance between the C≡N out-of-plane vibration mode and the C-CN out-of-plane vibration mode have been analyzed.
Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130103, Jilin Province, PR China; State Key Laboratory of Superhard Materials, Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, Jilin Province, PR China.
DongFei
D
Li
Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130103, Jilin Province, PR China.
KeWei
K
Zhang
College of Information and Technology, Jilin Normal University, Siping 136000, Jilin Province, PR China.
MingXing
M
Song
Institute of Translational Medicine, the First Hospital, Jilin University, Changchun 130061, Jilin Province, PR China.
NaiCui
N
Zhai
State Key Laboratory of Superhard Materials, Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, Jilin Province, PR China. Electronic address: chenglin@jlu.edu.cn.
ChengLin
C
Sun
Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130103, Jilin Province, PR China. Electronic address: goodldf@gmail.com.
HaiBo
H
Li
Fermi resonance; High pressure; Raman spectroscopy; Terephthalonitrile