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 Apr 15;213:199-203. doi: 10.1016/j.saa.2019.01.019. Epub 2019 Jan 16.
Vibrational properties of the crystalline p-quaterphenyl at low temperature are investigated by Raman scattering. The temperature dependent vibrational behaviors associated with the intra- and intermolecular terms are analyzed in detail. The order-disorder transition makes significant impacts on the energies, widths, and intensities of the vibrational modes, and the drastic splits of the modes mainly result from the sudden decline of the peak widths. Meanwhile, the intensity ratio of the 1280-cm and 1220-cm mode exhibits anomalous tendency around the transition temperature, as well as the frequency separations between them and between the higher energy mode and the lower energy mode around 1600 cm. Thus, they still can well indicate the molecular planarity in the low temperature conditions. However, the intensity ratio of the two modes around 1600 cm is no longer to be a good indicator of this transition due to the bare anomalous behavior around the transition temperature. Our work is of important significance for understanding the internal vibrational properties of p-quaterphenyl, and it also provides considerable supports for the further study of this material.
通过拉曼散射研究了低温下结晶对三联苯的振动特性。详细分析了与分子内和分子间项相关的温度相关的振动行为。有序-无序转变对振动模式的能量、宽度和强度有显著影响，模式的急剧分裂主要是由于峰值宽度的突然下降。同时，在转变温度附近，1280cm 和 1220cm 模式的强度比以及它们之间以及它们与 1600cm 左右的高能模式和低能模式之间的频率间隔表现出异常趋势。因此，它们仍然可以很好地表明在低温条件下分子的平面性。然而，由于在转变温度附近的明显异常行为，1600cm 左右的两个模式的强度比不再是这种转变的良好指标。我们的工作对于理解对三联苯的内部振动特性具有重要意义，并且也为进一步研究这种材料提供了相当大的支持。
