Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China; University of Science and Technology of China, Hefei 230026, China; Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.
Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2019 Jan 5;206:202-206. doi: 10.1016/j.saa.2018.07.104. Epub 2018 Aug 3.
Raman scattering measurements are performed on crystalline biphenyl at low temperatures. The properties of the vibrational modes focused on the intra- and intermolecular terms are analyzed in detail. Nearly all of the vibration modes exhibit hardening and simultaneously sharpen with decreasing temperature, whereas the modes at around 250 cm and 1280 cm soften their energies as temperature is decreased. Moreover, all the internal modes have anomalous reversals at around 45 K on the frequencies, widths, and intensities, and below 45 K, several new internal modes appear. Results of the analyses indicate that the reemergence of the interring tilt angle of the molecules at 45 K has a significant impact on the vibrational properties of biphenyl. Our work thus paves interesting and essential groundwork for the further study of biphenyl.
拉曼散射测量在低温下对联苯晶体进行。详细分析了聚焦于分子内和分子间项的振动模式的性质。几乎所有的振动模式都随着温度的降低而变硬并同时变锐，而在 250cm 和 1280cm 左右的模式随着温度的降低而降低能量。此外，所有的内部模式在频率、宽度和强度上在 45 K 左右都有异常反转，在 45 K 以下，出现了几个新的内部模式。分析结果表明，分子间环倾斜角在 45 K 时的重新出现对联苯的振动性质有重大影响。因此，我们的工作为进一步研究联苯奠定了有趣而重要的基础。
