How does water affect the dynamics of the room-temperature ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate and the fluorescence spectroscopy of coumarin-153 when dissolved in it?

被引:68
作者
Annapureddy, Harsha V. R. [1 ]
Hu, Zhonghan [1 ]
Xia, Junchao [1 ]
Margulis, Claudio J. [1 ]
机构
[1] Univ Iowa, Dept Chem, Iowa City, IA 52242 USA
关键词
D O I
10.1021/jp077623k
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
Molecular dynamics simulations of mixtures of 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM+][PF6-]) and water have been performed in order to investigate how small amounts of water affect the translational and rotational dynamics of this ionic liquid (IL). We find that water is closely associated with the anions and that its presence enhances both the translational and rotational dynamics of the IL. In agreement with experiments, we find that the fluorescence spectra of Coumarin-153 is red-shifted because of the presence of water. Small amounts of water enhance the speed of relaxation of the solvent surrounding the solute probe after photoexcitation, but only at a "local environment" level. Interconversion between environments still occurs on a long time scale compared with the fluorescence lifetime of the probe. Excitation wavelength-dependent emission is observed both in the neat IL and in the IL+water mixture.
引用
收藏
页码:1770 / 1776
页数:7
相关论文
共 92 条
[41]   Solute rotation and solvation dynamics in a room-temperature ionic liquid [J].
Ingram, JA ;
Moog, RS ;
Ito, N ;
Biswas, R ;
Maroncelli, M .
JOURNAL OF PHYSICAL CHEMISTRY B, 2003, 107 (24) :5926-5932
[42]   Solvation dynamics in acetonitrile: A study incorporating solute electronic response and nuclear relaxation [J].
Ingrosso, F ;
Ladanyi, BM ;
Mennucci, B ;
Elola, MD ;
Tomasi, J .
JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (08) :3553-3564
[43]   The probe dependence of solvation dynamics and rotation in the ionic liquid 1-butyl-3-methyl-imidazolium hexafluorophosphate [J].
Ito, N ;
Arzhantsev, S ;
Maroncelli, M .
CHEMICAL PHYSICS LETTERS, 2004, 396 (1-3) :83-91
[44]   Solvation dynamics and rotation of coumarin 153 in alkylphosphonium ionic liquids [J].
Ito, N ;
Arzhantsev, S ;
Heitz, M ;
Maroncelli, M .
JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (18) :5771-5777
[45]   Solvation dynamics and electric field relaxation in an imidazolium-PF6 ionic liquid:: From room temperature to the glass transition [J].
Ito, Naoki ;
Richert, Ranko .
JOURNAL OF PHYSICAL CHEMISTRY B, 2007, 111 (18) :5016-5022
[46]  
Jiang W, 2007, J PHYS CHEM B, V111, P4812, DOI 10.1021/jp0671421
[47]   Heterogeneous solute dynamics in room temperature ionic liquids [J].
Jin, Hui ;
Li, Xiang ;
Maroncelli, Mark .
JOURNAL OF PHYSICAL CHEMISTRY B, 2007, 111 (48) :13473-13478
[48]   Solvation and rotational dynamics of coumarin 153 in ionic liquids: Comparisons to conventional solvents [J].
Jin, Hui ;
Baker, Gary A. ;
Arzhantsev, Sergei ;
Dong, Jing ;
Maroncelli, Mark .
JOURNAL OF PHYSICAL CHEMISTRY B, 2007, 111 (25) :7291-7302
[49]   Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids [J].
Jorgensen, WL ;
Maxwell, DS ;
TiradoRives, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (45) :11225-11236
[50]   Dynamics of solvation of the fluorescent state of some electron donor-acceptor molecules in room temperature ionic liquids, [BMIM][(CF3SO2)2N] and [EMIM][(CF3SO2)2N] [J].
Karmakar, R ;
Samanta, A .
JOURNAL OF PHYSICAL CHEMISTRY A, 2003, 107 (38) :7340-7346