Solvation and rotational dynamics of coumarin 153 in ionic liquids: Comparisons to conventional solvents

被引:289
作者
Jin, Hui
Baker, Gary A.
Arzhantsev, Sergei
Dong, Jing
Maroncelli, Mark
机构
[1] Penn State Univ, Dept Chem, University Pk, PA 16802 USA
[2] Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA
关键词
D O I
10.1021/jp070923h
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Steady-state and time-resolved emission spectroscopy with 25 ps resolution are used to measure equilibrium and dynamic aspects of the solvation of coumarin 153 (C153) in a diverse collection of 21 room-temperature ionic liquids. The ionic liquids studied here include several phosphonium and imidazolium liquids previously reported as well as 12 new ionic liquids that incorporate two homologous series of ammonium and pyrrolidinium cations. Steady-state absorption and emission spectra are used to extract solvation free energies and reorganization energies associated with the S-0 <-> S-1 transition of C153. These quantities, especially the solvation free energy, vary relatively little in ionic liquids compared to conventional solvents. Some correlation is found between these quantities and the mean separation between ions (or molar volume). Time-resolved anisotropies are used to observe solute rotation. Rotation times measured in ionic liquids correlate with solvent viscosity in much the same way that they do in conventional polar solvents. No special frictional coupling between the C153 and the ionic liquid solvents is indicated by these times. But, in contrast to what is observed in most low-viscosity conventional solvents, rotational correlation functions in ionic liquids are nonexponential. Time-resolved Stokes shift measurements are used to characterize solvation dynamics. The solvation response functions in ionic liquids are also nonexponential and can be reasonably represented by stretched-exponential functions of time. The solvation times observed are correlated with the solvent viscosity, and the much slower solvation in ionic liquids compared to dipolar solvents can be attributed to their much larger viscosities. Solvation times of the majority of ionic liquids studied appear to follow a single correlation with solvent viscosity. Only liquids incorporating the largest phosphonium cation appear to follow a distinctly different correlation.
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收藏
页码:7291 / 7302
页数:12
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共 92 条
  • [21] Dynamic solvation in room-temperature ionic liquids
    Chowdhury, PK
    Halder, M
    Sanders, L
    Calhoun, T
    Anderson, JL
    Armstrong, DW
    Song, X
    Petrich, JW
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (29) : 10245 - 10255
  • [22] HOW DO MOLECULES MOVE NEAR T-G - MOLECULAR ROTATION OF 6 PROBES IN O-TERPHENYL ACROSS 14 DECADES IN TIME
    CICERONE, MT
    BLACKBURN, FR
    EDIGER, MD
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1995, 102 (01) : 471 - 479
  • [23] ANALYSIS OF TIME-RESOLVED FLUORESCENCE ANISOTROPY DECAYS
    CROSS, AJ
    FLEMING, GR
    [J]. BIOPHYSICAL JOURNAL, 1984, 46 (01) : 45 - 56
  • [24] Liquid phase behavior of ionic liquids with alcohols: Experimental studies and modeling
    Crosthwaite, JM
    Muldoon, MJ
    Aki, SNVK
    Maginn, EJ
    Brennecke, JF
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2006, 110 (18) : 9354 - 9361
  • [25] Solvent-solute interactions in ionic liquids
    Crowhurst, L
    Mawdsley, PR
    Perez-Arlandis, JM
    Salter, PA
    Welton, T
    [J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2003, 5 (13) : 2790 - 2794
  • [26] Dielectric response of imidazolium-based room-temperature ionic liquids
    Daguenet, Corinne
    Dyson, Paul J.
    Krossing, Ingo
    Oleinikova, Alla
    Slattery, John
    Wakai, Chihiro
    Weingaertner, Hermann
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2006, 110 (25) : 12682 - 12688
  • [27] Prediction of infinite dilution activity coefficients of organic compounds in ionic liquids using COSMO-RS
    Diedenhofen, M
    Eckert, F
    Klamt, A
    [J]. JOURNAL OF CHEMICAL AND ENGINEERING DATA, 2003, 48 (03) : 475 - 479
  • [28] Predicting infinite-dilution activity coefficients of organic solutes in ionic liquids
    Eike, DM
    Brennecke, JF
    Maginn, EJ
    [J]. INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 2004, 43 (04) : 1039 - 1048
  • [29] Air and water stable ionic liquids in physical chemistry
    Endres, Frank
    El Abedin, Sherif Zein
    [J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2006, 8 (18) : 2101 - 2116
  • [30] Densities and derived thermodynamic properties of ionic liquids.: 3.: Phosphonium-based ionic liquids over an extended pressure range
    Esperança, JMSS
    Guedes, HJR
    Blesic, M
    Rebelo, LPN
    [J]. JOURNAL OF CHEMICAL AND ENGINEERING DATA, 2006, 51 (01) : 237 - 242