Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (7): 1275-1282.doi: 10.3866/PKU.WHXB201504211

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Intermolecular Hydrogen Bonding Structural Dynamics in Ethylene Glycol by Femtosecond Nonlinear Infrared Spectroscopy

YANG Fan1, YU Peng-Yun1,2, ZHAO Juan1, ZHAO Yan3, WANG Jian-Ping1   

  1. 1 Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China;
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China;
    3 College of Physics & Electronics Engineering, Shanxi University, Taiyuan 030006, P. R. China
  • Received:2015-01-14 Revised:2015-04-17 Published:2015-07-08
  • Contact: WANG Jian-Ping E-mail:jwang@iccas.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21103200, 20727001, 91121020) and Major Research Equipment Development Project of the Chinese Academy of Sciences (Y2201220).

Abstract:

In this work, we examined the structural and ―OH stretching vibrational dynamics of ethylene glycol (EG) solvated in acetonitrile (MeCN), acetone (AC), tetrahydrofuran (THF), and dimethylsulfoxide (DMSO) using steady-state linear infrared (IR) spectroscopy and ultrafast pump-probe IR spectroscopy. The results suggested that the frequency position, bandwidth, and vibrational relaxation of the ―OH stretching vibration that participate in the formation of intermolecular hydrogen bonds (IHBs) were strongly influenced by the type of solvent. At least two types of IHBs were detected in the EG solution including clustered solute-solute IHBs and solute-solvent IHBs. Quantum chemical calculations predicted a similar solvent dependence of the ―OH stretching vibrational frequency to that observed in the IR experiments. Furthermore, we found that the IHB-involved ―OH stretching mode in the case of solute-solvent clusters displayed the slowest population relaxation dynamics in the case of EG in MeCN. The relaxation became slightly faster in AC and even faster in THF. The fastest dynamics was observed in the case of EG in DMSO. However, in each solvent environment examined, the IHB-involved ―OH stretching mode in the solute-solute cluster displayed the fastest population relaxation. The results obtained in this study provide further insights into different IHB structural dynamics in co-existing solute-solute and solutesolvent clusters.

Key words: Ethylene glycol, Ultrafast pump-probe infrared spectroscopy, Solute-solvent cluster, Intermolecular hydrogen bond, Vibrational relaxation

MSC2000: 

  • O641