TitleProbing local environments in ionic liquids
NameFadeeva, Tatiana (author), Castner, Edward W (chair), Krogh-Jespersen, Karsten (internal member), Case, David A (internal member), Greenbaum, Steven (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectChemistry and Chemical Biology,
DescriptionThe polarity and solvation properties were investigated for four ionic liquids with non-aromatic cation. The four ionic liquids studied were: N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)-imide (Pyrr14+/NTf2-), N-methyl-N-ethoxyethylpyrrolidinium bis(trifluoromethylsulfonyl)-imide (Pyrr1(202)+/NTf2-), N-methyl-tri-N-butylammonium bis(trifluoromethylsulfonyl) -imide (N1444+/NTf2-) and N-hexyl-tri-N-butylammonium bis(trifluoromethylsulfonyl) -imide (N6444+/NTf2-). The ammonium based ILs exhibit slightly higher polarity than pyrrolidinium based ILs. The solvation dynamics of the fluorescence probe molecule Coumarin 153 exhibits multi-exponential character in all four ILs. The observed solvation dynamics occur on timescales orders of magnitude longer than for most organic solvents. The reorientational dynamics investigated by method of time-resolved fluorescence anisotropy decay is faster than predicted by hydrodynamic theory. The ionic liquid/water interaction were characterized for hydrophobic and water- miscible ionic liquids. The two ionic liquids studied were: 1-butyl-1-methyl- pyrrolidinium bis( trifluoromethylsulfonyl)amide (Pyrr14+ /NTf2-) and 1-butyl-1-methylpyrrolidinium Trifloromethylsulfonate (Pyrr14+/OTf-). The concentration dependence of water proton chemical shift δH2O reveals different water-anion interaction in these two ILs. The diffusion properties were investigated in the system IL/water by pulse gradient DOSY experiments. The diffusional behavior of cations and anions is very similar whereas water exhibits anomalously high diffusion rate. The diffusional properties of water are different in two ILs. The ratio DH2O / Dcation is higher for more hydrophobic Pyrr14+ /NTf2- that confirms weaker water-anion interaction in this liquid.
NoteIncludes bibliographical references
Noteby Tatiana A. Fadeeva
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.