Jump to main content
Jump to site search

Issue 20, 2008
Previous Article Next Article

Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xHx−1]

Author affiliations

Abstract

We describe a fluidity and conductivity study as a function of composition in N-methylpyrrolidine–acetic acid mixtures. The simple 1 : 1 acid–base mixture appears to form an ionic liquid, but its degree of ionicity is quite low and such liquids are better thought of as poorly dissociated mixtures of acid and base. The composition consisting of 3 moles acetic acid and 1 mole N-methylpyrrolidine is shown to form the highest ionicity mixture in this binary due to the presence of oligomeric anionic species [(AcO)xHx−1] stabilised by hydrogen bonds. These oligomeric species, being weaker bases than the acetate anion, shift the proton transfer equilibrium towards formation of ionic species, thus generating a higher degree of ionicity than is present at the 1 : 1 composition. A Walden plot analysis, thermogravimetric behaviour and proton NMR data, as well as ab initio calculations of the oligomeric species, all support this conclusion.

Graphical abstract: Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xHx−1]−

Back to tab navigation

Publication details

The article was received on 25 Jan 2008, accepted on 26 Feb 2008 and first published on 20 Mar 2008


Article type: Paper
DOI: 10.1039/B801405A
Citation: Phys. Chem. Chem. Phys., 2008,10, 2972-2978
  •   Request permissions

    Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xHx−1]

    K. M. Johansson, E. I. Izgorodina, M. Forsyth, D. R. MacFarlane and K. R. Seddon, Phys. Chem. Chem. Phys., 2008, 10, 2972
    DOI: 10.1039/B801405A

Search articles by author

Spotlight

Advertisements