Abstract
Ion pair speciation of ionic liquids (ILs) has an important effect on the physical and chemical properties of ILs and recognition of the structure of ion pairs in solution is essential. It has been reported that ion pairs of some ILs can be formed by hydrogen bonding interactions between cations and anions of them. Considering the fact that far-IR (FIR) spectroscopy is a powerful tool in indicating the intermolecular and intramolecular hydrogen bonding, in this work, this spectroscopic technique has been combined with molecular dynamic (MD) simulation and nuclear magnetic resonance hydrogen spectroscopy (1H NMR) to investigate ion pairs of aprotic ILs [Bmim][NO3], [BuPy][NO3], [Pyr14][NO3], [PP14][NO3] and [Bu-choline][NO3] in aqueous IL mixtures. The FIR spectra have been assigned with the aid of density functional theory (DFT) calculations, and the results are used to understand the effect of cationic nature on the structure of ion pairs. It is found that contact ion pairs formed in the neat aprotic ILs by hydrogen bonding interactions between cation and anion, were still maintained in aqueous solutions up to high water mole fraction (say 0.80 for [BuPy][NO3]). When water content was increased to a critical mole fraction of water (say 0.83 for [BuPy][NO3]), the contact ion pairs could be transformed into solvent-separated ion pairs due to the formation of the hydrogen bonding between ions and water. With the further dilution of the aqueous ILs solution, the solvent-separated ion pairs was finally turned into free cations and free anions (fully hydrated cations or anions). The concentrations of the ILs at which the contact ion pairs were transformed into solvent-separated ion pairs and solvent-separated ion pairs were transformed into free ions (fully hydrated ion) were dependent on the cationic structures. These information provides direct spectral evidence for ion pair structures of the aprotic ILs in aqueous solution. MD simulation and 1H NMR results support the conclusion drawn from FIR spectra investigations.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Zhang S, Sun J, Zhang X, Xin J, Miao Q, Wang J. Chem Soc Rev, 2014, 43: 7838–7869
Zhang L, Dong K, Chen S, Zhang S. Sci China Chem, 2016, 59: 547–550
Chen S, Zhang S, Liu X, Wang J, Wang J, Dong K, Sun J, Xu B. Phys Chem Chem Phys, 2014, 16: 5893–5906
Zhu Q, Ma J, Kang X, Sun X, Hu J, Yang G, Han B. Sci China Chem, 2016, 59: 551–556
Hayes R, Warr GG, Atkin R. Chem Rev, 2015, 115: 6357–6426
Dupont J. Acc Chem Res, 2011, 44: 1223–1231
Neto BAD, Meurer EC, Galaverna R, Bythell BJ, Dupont J, Cooks RG, Eberlin MN. J Phys Chem Lett, 2012, 3: 3435–3441
Marcus Y, Hefter G. Chem Rev, 2006, 106: 4585–4621
Dupont J. J Braz Chem Soc, 2004, 15: 341–350
Zahn S, Uhlig F, Thar J, Spickermann C, Kirchner B. Angew Chem Int Ed, 2008, 47: 3639–3641
Tsuzuki S, Tokuda H, Hayamizu K, Watanabe M. J Phys Chem B, 2005, 109: 16474–16481
Fumino K, Reimann S, Ludwig R. Phys Chem Chem Phys, 2014, 16: 21903–21929
Fumino K, Ludwig R. J Mol Liq, 2014, 192: 94–102
Consorti CS, Suarez PAZ, de Souza RF, Burrow RA, Farrar DH, Lough AJ, Loh W, da Silva LHM, Dupont J. J Phys Chem B, 2005, 109: 4341–4349
Sadeghi R, Ebrahimi N. J Phys Chem B, 2011, 115: 13227–13240
Li W, Zhang Z, Han B, Hu S, Xie Y, Yang G. J Phys Chem B, 2007, 111: 6452–6456
Katsuta S, Imai K, Kudo Y, Takeda Y, Seki H, Nakakoshi M. J Chem Eng Data, 2008, 53: 1528–1532
Dorbritz S, Ruth W, Kragl U. Adv Synth Catal, 2005, 347: 1273–1279
Gozzo FC, Santos LS, Augusti R, Consorti CS, Dupont J, Eberlin MN. Chem Eur J, 2004, 10: 6187–6193
Bini R, Bortolini O, Chiappe C, Pieraccini D, Siciliano T. J Phys Chem B, 2007, 111: 598–604
Neto B, Ebeling G, Goncalves R, Gozzo F, Eberlin M, Dupont J. Synthesis, 2004: 1155–1158
Avent AG, Chaloner PA, Day MP, Seddon KR, Welton T. J Chem Soc Dalton Trans, 1994: 3405–3413
Mele A, Tran CD, De Paoli Lacerda SH. Angew Chem Int Ed, 2003, 42: 4364–4366
Scharf NT, Stark A, Hoffmann MM. J Solution Chem, 2013, 42: 2034–2056
Zheng YZ, Wang NN, Luo JJ, Zhou Y, Yu ZW. Phys Chem Chem Phys, 2013, 15: 18055–18064
Bešter-Rogač M, Stoppa A, Hunger J, Hefter G, Buchner R. Phys Chem Chem Phys, 2011, 13: 17588–17598
Stoppa A, Hunger J, Hefter G, Buchner R. J Phys Chem B, 2012, 116: 7509–7521
Batista MLS, Kurnia KA, Pinho SP, Gomes JRB, Coutinho JAP. J Phys Chem B, 2015, 119: 1567–1578
Roohi H, Khyrkhah S. Comp Theor Chem, 2014, 1037: 70–79
Zhang L, Xu Z, Wang Y, Li H. J Phys Chem B, 2008, 112: 6411–6419
Zanatta M, Girard AL, Simon NM, Ebeling G, Stassen HK, Livotto PR, dos Santos FP, Dupont J. Angew Chem Int Ed, 2014, 53: 12817–12821
Yaghini N, Pitawala J, Matic A, Martinelli A. J Phys Chem B, 2015, 119: 1611–1622
Yaghini N, Nordstierna L, Martinelli A. Phys Chem Chem Phys, 2014, 16: 9266–9275
Ren Z, Brinzer T, Dutta S, Garrett-Roe S. J Phys Chem B, 2015, 119: 4699–4712
Strauch M, Roth C, Kubatzki F, Ludwig R. ChemPhysChem, 2014, 15: 265–270
Fumino K, Stange P, Fossog V, Hempelmann R, Ludwig R. Angew Chem Int Ed, 2013, 52: 12439–12442
Pierola IF, Agzenai Y. J Phys Chem B, 2012, 116: 3973–3981
Fumino K, Wulf A, Ludwig R. Angew Chem Int Ed, 2008, 47: 8731–8734
Wulf A, Fumino K, Ludwig R. Angew Chem Int Ed, 2010, 49: 449–453
Fumino K, Reichert E, Wittler K, Hempelmann R, Ludwig R. Angew Chem Int Ed, 2012, 51: 6236–6240
Fumino K, Wulf A, Ludwig R. Angew Chem Int Ed, 2009, 48: 3184–3186
Fumino K, Wulf A, Ludwig R. Angew Chem Int Ed, 2008, 47: 3830–3834
Roth C, Peppel T, Fumino K, Köckerling M, Ludwig R. Angew Chem Int Ed, 2010, 49: 10221–10224
Stassen HK, Ludwig R, Wulf A, Dupont J. Chem Eur J, 2015, 21: 8324–8335
Stange P, Fumino K, Ludwig R. Angew Chem Int Ed, 2013, 52: 2990–2994
Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Scalmani G, Barone V, Mennucci B, Petersson GA, et al. Gaussian 09. Revision D.01. Wallingford, CT: Gaussian, Inc., 2009
Boys SF, Bernardi F. Mol Phys, 1970, 19: 553–566
Liu X, Zhou G, Zhang S, Wu G, Yu G. J Phys Chem B, 2007, 111: 5658–5668
Freire MG, Neves CMSS, Shimizu K, Bernardes CES, Marrucho IM, Coutinho JAP, Canongia Lopes JN, Rebelo LPN. J Phys Chem B, 2010, 114: 15925–15934
Wu Y, Tepper HL, Voth GA. J Chem Phys, 2006, 124: 024503–024503
Lyubartsev AP, Laaksonen A. Comp Phys Commun, 2000, 128: 565–589
Tuckerman M, Berne BJ, Martyna GJ. J Chem Phys, 1992, 97: 1990–2001
Leeuw SWD, Perram JW, Smith ER. Proc R Soc A-Math Phys Eng Sci, 1983, 388: 177–193
Martyna GJ, Tuckerman ME, Tobias DJ, Klein ML. Mol Phys, 1996, 87: 1117–1157
Köddermann T, Klembt S, Klasen D, Paschek D, Kragl U, Ludwig R. ChemPhysChem, 2012, 13: 1748–1752
Zhao Y, Wang J, Wang H, Li Z, Liu X, Zhang S. J Phys Chem B, 2015, 119: 6686–6695
Koch W, Holthausen MC. A Chemist’s Guide to Density Functional Theory. 2nd Ed. Weinheim: Wiley-VCH Verlag GmbH, 2001
Zhao Y, Gao S, Wang J, Tang J. J Phys Chem B, 2008, 112: 2031–2039
Karve L, Dutt GB. J Phys Chem B, 2012, 116: 1824–1830
Remsing RC, Liu Z, Sergeyev I, Moyna G. J Phys Chem B, 2008, 112: 7363–7369
Singh T, Kumar A. J Phys Chem B, 2007, 111: 7843–7851
Acknowledgments
This work was supported by the National Natural Science Foundation of China (21573060, 21673068), Program for Innovative Research Team in Science and Technology in University of Henan Province (16IRTSTHN002), Plan for Scientific Innovation Talent of Henan Province (144200510004) and The High Performance Computing Center of Henan Normal University.
Author information
Authors and Affiliations
Corresponding authors
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Wang, H., Liu, M., Zhao, Y. et al. Hydrogen bonding mediated ion pairs of some aprotic ionic liquids and their structural transition in aqueous solution. Sci. China Chem. 60, 970–978 (2017). https://doi.org/10.1007/s11426-016-0389-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11426-016-0389-4