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Spectroscopic and DFT Studies of Cation-Anion Interaction in Imidazolium and Piperidinium Based Ionic Liquids
Interaction in various imidazolium and piperidinium Ionic Liquids (ILs) as well as their strength has been discussed using NMR and IR spectroscopic techniques with strapping support from DFT calculation. Strong hydrogen bonding interaction in imidazolium/ piperidinium halide based ILs as compared to PF6, BF4 and NTf2 containing ILs has been explained well with the help of spectroscopy. Higher viscosity of bmimPF6 compared to bmimBF4 and bmimNTf2 has been elucidated due to strong interaction of C2-H with anion, observed in NMR and IR spectroscopy and has been sturdily supported by DFT calculated IR frequencies showing blue shift in C2-H stretching when moving from bmimPF6 to bmimNTf2. Further, a molecular level comparison of PIP14Br and bmimBr (PIP14Br=N-butyl-N-methylpiperidinium bromide, melting point (mp): 241°C and bmimBr = 1-butyl-3-methylimidazolium bromide, mp: 79°C) have pointed out that more number of strong classical hydrogen bonding interactions in the former is primarily responsible for much higher melting point. Hence significance variation in number and strength of H-bonding in ILs predominantly controls the physical property of the salt/ionic liquids.
DFT Calculation, Hydrogen Bonding, Ionic Liquids, Spectroscopy.
- K. R. Seddon, “Ionic liquids: A taste of the future,” Nature Materials, vol. 2, no. 2, p. 363, 2003.
- J. Dupont, ”On the solid, liquid and solution structural organization of imidazolium ionic liquids,” Journal of Brazilian Chemical Society, vol. 15, no. 3, pp. 341-350, 2004.
- S. Saha, and H. Hamaguchi, ”Effect of water on the molecular structure and arrangement of nitrile-functionalized ionic liquids,” Journal of Physical Chemistry B, vol. 110, no. 6, pp. 2777-2781, 2006.
- S. Saha, S. Hayashi, A. Kobayashi and H. Hamaguchi, “Crystal structure of 1-Butyl-3-methylimidazolium chloride. A clue to the elucidation of the ionic liquid structure,” Chemical Letters, vol. 32, pp. 740-741, 2003.
- H. C. Chang, J. C. Jiang, C. Y. Chang, J. C. Su, C. H. Hung, Y. C. Liou and S. H. Lin, “Structural organization in aqueous solutions of 1-butyl-3-methylimidazolium halides: A high-pressure infrared spectroscopic study on ionic liquids,” Journal of Physical Chemistry B, vol. 112, no. 14, pp. 4351-4356, 2008.
- G. E. Logotheti, J. Ramos and I. G. Economou, “Molecular modeling of imidazolium-based [Tf2N-] ionic liquids: Microscopic structure, thermodynamic and dynamic properties, and segmental dynamics,” The Journal of Physical Chemistry B, vol. 113, no. 20, pp. 7211-7224, 2009.
- E. R. Talaty, S. Raja, V. J. Storhaug, A. Dolle, and W. R. Carper, “Raman and infrared spectra and ab initio calculations of C2-4MIM Imidazolium Hexafluorophosphate ionic liquids,” The Journal of Physical Chemistry B, vol. 108, no. 35, pp. 13177-13184, 2004.
- K. Dong, S. Zhang, D. Wang and X. Yao, “Hydrogen bonds in Imidazolium ionic liquids,” The Journal of Physical Chemistry A, vol. 110, no. 31, pp. 9775-9782, 2006.
- E. A. Turner, C. C. Pye, and R. D. Singer, “Use of ab initio calculations toward the rational design of room temperature ionic liquids,” The Journal of Physical Chemistry A, vol. 107, no. 13, pp. 2277-2288, 2003.
- R. Ozawa, S. Hayashi, S. Saha, A. Kobayashi and H. Hamaguchi, “Rotational Isomerism and structure of the 1-butyl-3-methylimidazolium cation in the iconic liquid state,” Chemical Letters, vol. 32, no. 10, pp. 948-949, 2003.
- H. Hamaguchi and R. Ozawa, “Structure of ionic liquids and ionic liquid compounds: Are ionic liquids genuine liquids in the conventional sense,” Advances in Chemical Physics, vol. 131, pp. 85-104, 2005.
- K. Fumino, A. Wulf, and R. Ludwig, “The potential role of hydrogen bonding in aprotic and protic ionic liquids,” Physical Chemistry Chemical Physics, vol. 11, no. 39, pp. 87908794, October, 2009.
- A. Wulf, K. Fumino and R. Ludwig, “Spectroscopic Evidence for an enhanced anion-cation interaction from Hydrogen bonding in pure Imidazolium ionic liquids,” Angewandte Chemie International Edition, vol. 49, no. 2, pp. 449-453, 2010.
- V. Kempter, and B. Kirchner, “The role of hydrogen atoms in interactions involving imidazolium-based ionic liquids,” Journal of Molecular Structure, vol. 972, no. 1, pp. 22-34, 2010.
- M. J. Frisch, et.al, “Expanding the limits of computational chemistry,” Gaussian, Inc. Wallingford, CT, 2009.
- A. D. Becke, “Density-functional thermo-chemistry III. The role of exact exchange,” The Journal of Chemical Physics, vol. 98, no. 7, pp. 5648-5653, 1993.
- C. Lee, W. Yang, and R. G. Parr, “Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density,” Physical Review B, vol. 37, pp. 785-789, 1988.
- N. Godbout, D. R. Salahub, J. Andzelm, and E. Wimmer, “Optimization of Gaussian-type basis sets for local spin density functional calculations Part I. Boron through neon, optimization technique and validation,” Canadian Journal of Chemistry, vol. 70, no. 2, pp. 560-571, 1992.
- S. Tsuzuki, R. Katoh and M. Mikami, “Analysis of interactions between 1-butyl-3-methylimidazolium cation and halide anions (Cl-, Br- and I-) by ab initio calculations: Anion size effects on preferential locations of anions,” Molecular Physics, vol. 106, no. 12-13, pp. 1621-1629, 2008.
- M. Shukla, N. Srivastava and S. Saha, “Interactions and transitions in Imidazolium Cation based ionic liquids in ionic liquids- New aspect for the future,” In Tech Publisher, pp. 153-170, 2011.
- M. Shukla, N. Srivastava, and S. Saha, “Theoretical and spectroscopic studies of 1-butyl-3- methyl imidazolium iodide room temperature ionic liquid: Its differences with chloride and bromide derivatives,” Journal of Molecular Structure, vol. 975, no. 1, pp. 349-356, 2010.
- S. Tsuzuki, A. A. Arai, and K. Nishikawa, “Con-formational analysis of 1-Butyl-3-methylimidazolium by CCSD (T) level ab initio calculations: Effects of neighbouring anions,” The Journal of Physical Chemistry B, vol. 112, no. 26, pp. 7739-7747, 2008.
- H. J. Reich, “Structure determination using spectroscopic methods,” Available http://www.chem.wisc.edu/areas/reich/chem605/index.htm, 2012.
- J. G. Huddleston, A. E. Visser, W. M. Reichert, H. D. Willauer, G. A. Broker and R. D. Rogers, “Characterization and comparison of hydrophilic and hydrophobic room temperature ionic liquids incorporating the imidazolium cation,” Green Chemistry, vol. 3, no. 4, pp. 156-164, 2001.
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