Interactions of pyridinium, pyrrolidinium or piperidinium based ionic liquids with water: Measurements and COSMO-RS modelling

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• 作者：Imran Khan^a ; Mohamed Taha^a ; Simã ; o P. Pinho^b ; Joã ; o A.P. Coutinho^a ; ^{jcoutinho@ua.pt" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Activity coefficient ; Water activity ; COSMO-RS ; Hydrogen bonding ; Excess enthalpy
• 刊名：Fluid Phase Equilibria
• 出版年：2016
• 出版时间：25 April 2016
• 年：2016
• 卷：414
• 期：Complete
• 页码：93-100
• 全文大小：1615 K

文摘

Looking for a better knowledge concerning water and ionic liquids (ILs) interactions, a systematic study of the activity coefficients of water in pyridinium, pyrrolidinium and piperidinium-based ILs at 298.2 K is here presented based on water activity measurements. Additionally, the study of the structural effects of the pyridinium-based cation is also pursued. The results show that non-aromatic ILs are interacting more with water than aromatic ones, and among the ortho, meta and para isomers of 1-butyl-methylpyridinium chloride, the ortho position confers a more hydrophilic character to that specific IL. The physical-chemistry of the solutions was interpreted based on dissociation constants, natural bond orbitals and excess enthalpies providing a sound basis for the interpretation of the experimental observations. These results show that hydrogen bonding controls the behavior of these systems, being the anion-water one of the most relevant interactions, but modulated by the anion–cation interactions.