物理学报2018，Vol.67Issue(2)：113-120,8.DOI:10.7498/aps.67.20171828
液相硝基甲烷分子振动特性的相干反斯托克斯拉曼散射光谱
Coherent anti-Stokes Raman scattering spectrum of vibrational properties of liquid nitromethane molecules
摘要
Abstract
The initial decomposition micro-mechanism of energetic materials has attracted much attention because it is a critical factor for the safe use of energetic materials. The thermally triggered chemical reactions are usually related to the vibrational properties of molecules. A time-resolved coherent anti-Stokes Raman scattering(CARS)spectrum system is constructed to study the molecular coherent vibrational dynamics of nitromethane at a microscopic level for clarifying the relation of molecular vibration to initial chemical reaction. In this experiment, the ultra-continuous white light is used as Stokes light,and the CARS spectra of different vibrational modes can be obtained by adjusting the time delay of the Stokes light. The vibrational dephasing time of different chemical bonds in nitromethane is provided by fitting the vibrational relaxation curves. The dephasing time of the C—H stretching vibration located at 3000 cm?1is shown to be 0.18 ps, which is far less than the dephasing time 6.2 ps of the C—N stretching vibration located at 917 cm?1. The vibrational dephasing time is closely related to thermal collision for liquid nitromethane system without intermolecular hydrogen bond, that is, the scattering of thermal phonons causes the dephasing of coherent vibration. Therefore, the stretching vibration of the C—H bond is more easily affected by the thermal phonon than the stretching vibration of the C—N bond. The C—H bond of nitromethane molecule is expected to be excited first, causing an initial chemical reaction under thermal loading.关键词
含能材料/分子振动/相干反斯托克斯拉曼散射光谱/失相时间Key words
energetic materials/molecular vibration/coherent anti-Stokes Raman scattering spectra/dephasing time引用本文复制引用
彭亚晶,孙爽,宋云飞,杨延强..液相硝基甲烷分子振动特性的相干反斯托克斯拉曼散射光谱[J].物理学报,2018,67(2):113-120,8.基金项目
辽宁省自然科学基金(批准号:2015020248)和中国工程物理研究院流体物理研究所基金(批准号:HX2016140)资助的课题. Project supported by the Natural Science Foundation of Liaoning Province, China (Grant No. 2015020248) and the Fund of Institute of Fluid Physics of China Academy of Engineering Physics (Grant No. HX2016140). （批准号:2015020248）
