Microscopic study of binary mixtures between pyrrolidinium bis(triflorosulfonyl)imide and dimethyl sulfoxide/acetonitrile  

作　　者：Hamad Ashraf Yu Zhou Jing Xu Khalil Ahmad Zhi-Wu Yu 

机构地区：[1]Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education) [2]Department of Chemistry, Tsinghua University

出　　处：《Science China Chemistry》2016年第5期578-586,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21133009, 21473099)

摘　　要：Molecular interactions of a representative pyrrolidinium-based ionic liquid 1-butyl-l-methyl-pyrrolidinium bis（triflorosulfonyl）- imide （[BMPyrr][TFSI]） with dimethyl sulfoxide （DMSO） and acetonitrile （AN） have been analyzed in this work. Attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR） and density functional theory （DFT） calculations are used in the investigation, while excess infrared spectra and two-dimensional correlation spectroscopy are used to explore the data in detail. It has been found that the molecular solvents can interact with TFSI- （mainly with S=O and weakly with S-N-S group）. AN interacts feebly with BMPyrr＋ as compared with the strong interaction of DMSO. The strength of the interactions depends on the electron donating ability of the solvent. Upon mixing, hydrogen bonds regarding C-Hs in cation and S-N-S in anion are weakened, while that regarding S=O in anion is strengthened. Among the C-Hs which are connected directly with the N of the cation, Cl-H is the main interaction site for both DMSO and AN. This means that Cl-H is the most acidic hydrogen in pyrrolidinium cation.Molecular interactions of a representative pyrrolidinium-based ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(triflorosulfonyl)-imide([BMPyrr][TFSI]) with dimethyl sulfoxide(DMSO) and acetonitrile(AN) have been analyzed in this work. Attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR) and density functional theory(DFT) calculations are used in the investigation, while excess infrared spectra and two-dimensional correlation spectroscopy are used to explore the data in detail. It has been found that the molecular solvents can interact with TFSI-(mainly with S=O and weakly with S–N–S group). AN interacts feebly with BMPyrr^+ as compared with the strong interaction of DMSO. The strength of the interactions depends on the electron donating ability of the solvent. Upon mixing, hydrogen bonds regarding C-Hs in cation and S–N–S in anion are weakened, while that regarding S=O in anion is strengthened. Among the C-Hs which are connected directly with the N of the cation, C1-H is the main interaction site for both DMSO and AN. This means that C1-H is the most acidic hydrogen in pyrrolidinium cation.

关 键 词：ATR-FTIR DFT calculations excess infrared spectrum two-dimensional correlation spectroscopy ionic liquid hydrogen bond 

分 类 号：O645.1[理学—物理化学] O641.3[理学—化学]