Structural features of liquid DMSO from temperature-dependent Raman spectroscopy and theoretical calculations  

液相二甲基亚砜微观结构的拉曼光谱表征与理论计算研究

作　　者：Hongyuan Shen Ning Chen Ao You Yuanqin Yu Xiaoguo Zhou Rui Zhang Shilin Liu 沈鸿远;陈宁;游奥;喻远琴;周晓国;张瑞;刘世林(安徽大学物理与光电工程学院,合肥230601;中国科学技术大学化学物理系,合肥微尺度物质科学国家研究中心,能源材料化学协同创新中心,合肥230026)

机构地区：[1]School of Physics and Optoelectronic engineering,Anhui University,Hefei 230601,China [2]Hefei National Laboratory for Physical Sciences at the Microscale,iChEM(Collaborative Innovation Center of Chemistry for Energy Materials),Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China

出　　处：《Chinese Journal of Chemical Physics》2024年第6期763-768,I0008-I0010,I0041,I0042,共11页化学物理学报(英文)

基　　金：supported by the National Natural Science Foundation of China(Nos.21873002,22073088,12374001).

摘　　要：Dimethyl sulfoxide(DMSO)plays an important role in chemistry,biology and industry.The S=O stretching vibration serves as a sensitive probe of its structure under different chemical environments.However,spectral assignment for the S=O stretching vibration of liquid DMSO remains unclear due to the interference of CH_(3)antisymmetric rocking and different aggregates,leading to the confusion in explaining the microstructures of liquid DMSO.Here,the S=O stretching spectra in pure DMSO and in extremely diluted CCl_(4)solution were investigated with temperaturedependent Raman spectroscopy.It is shown that CH_(3)antisymmetric rocking does not significantly interfere with the S=O band profile due to its low Raman intensity.Three decomposed peaks at 1027,1042 and 1055 cm^(-1)in liquid DMSO show obviously different intensity variety upon the temperature increasing.Combined with quantum chemistry calculation on(DMSO)_(n)(n=1-4)clusters,Raman spectra in the S=O stretching region were assigned and the simultaneous presence of the monomer,dimer and trimmer in liquid DMSO were concluded.These results contribute to a more detailed molecular understanding of the structure of DMSO in the liquid state.二甲基亚砜(DMSO)在化学、生物学和工业等领域具有重要作用.S=O伸缩振动光谱可以作为研究其在不同化学环境下结构变化的探针.然而,由于CH_(3)反对称摇摆振动和不同聚集体的干扰,液相二甲基亚砜的S=O伸缩振动光谱归属仍不一致,导致对其微观结构的解释仍不清晰.本文利用变温拉曼光谱研究了二甲基亚砜在纯液相和极稀CCl_(4)溶液中的S=O伸缩振动光谱.结果表明,CH_(3)反对称摇摆振动峰的拉曼强度非常弱,对S=O伸缩振动光谱没有明显影响;纯液相条件下二甲基亚砜的拉曼光谱可以分解为三个振动峰,分别位于1027、1042和1055 cm^(-1).结合变温的拉曼光谱以及计算的(DMSO)_(n)(n=1~4)团簇结构,三个振动峰分别归属为二甲基亚砜的三聚体、二聚体和单体结构.这些结果为从分子水平上理解二甲基亚砜的微观结构提供依据.

关 键 词：Structural property Liquid DMSO Temperature-dependent Raman spectroscopy 

分 类 号：O62[理学—有机化学]