Effect of unsaturation on the absorption of ethane and ethylene in imidazolium-based ionic liquids

Leila Moura, Manas Mishra, Varinia Bernales, Patricio Fuentealba, Agilio A.H. Padua, Catherine C. Santini, Margarida F. Costa Gomes*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


The influence of the presence of imidazolium side chain unsaturation on the solubility of ethane and ethylene was studied in three ionic liquids: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide - saturated alkyl side-chain in the cation; 1-methyl-3-(buten-3-yl)imidazolium bis(trifluorosulfonyl)imide - double bond in the side-chain of the cation; and 1-methyl-3-benzylimidazolium bis(trifluorosulfonyl)imide - benzyl group in the side-chain of the cation. The solubility of both gases decreases when the side-chain of the cations is functionalized with an unsaturated group. This can be explained by a less favorable enthalpy of solvation. The difference of solubility between ethane and ethylene can be explained from a balance of enthalpic and entropic factors: for the ionic liquid with the saturated alkyl side-chain and the benzyl-substituted side-chain, it is the favorable entropy of solvation that explains the larger ethylene solubility, whereas in the case of the saturated side-chain, it is the more favorable enthalpy of solvation. Molecular simulation allowed the identification of the mechanisms of solvation and the preferential solvation sites for each gas in the different ionic liquids. Simulations have shown that the entropy of solvation is more favorable when the presence of the gas weakens the cation-anion interactions or when the gas can be solvated near different sites of the ionic liquid.

Original languageEnglish
Pages (from-to)7416-7425
Number of pages10
JournalJournal of Physical Chemistry B
Issue number24
Publication statusPublished - 20 Jun 2013
Externally publishedYes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Effect of unsaturation on the absorption of ethane and ethylene in imidazolium-based ionic liquids'. Together they form a unique fingerprint.

Cite this