Abstract
The complex between diisopropylethylamine (DIPEA) and formic acid has been reinvestigated. Mixing the compounds in the ratio 1:1 leads to a phase separation in which the upper phase is DIPEA, the lower phase is the “ionic liquid” named DIPEF. A combined NMR and DFT study shows that the lower phase primarily is formic acid:formate and diisopropyl-ammonium ions in the ratio 2:1 (acid:base) plus the formic acid dimer. Addition of more acid leads to more and more of the acid dimer. The proton transfer in the system is 65-80%. The structural picture presented in this paper is very different from that presented elsewhere. However, the present picture should be considered using acids and bases with a pKa difference less than 8. The formic acid content in the DIPEF ionic liquid causes desorption of the dye-sensitized solar cell (DSC) dye N719 from the photo anode and DIPEF is therefore not a suitable electrolyte for DSCs.
Originalsprog | Engelsk |
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Tidsskrift | The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical |
Vol/bind | 120 |
Udgave nummer | 43 |
Sider (fra-til) | 11279-11286 |
Antal sider | 8 |
ISSN | 1520-6106 |
DOI | |
Status | Udgivet - 12 okt. 2016 |
Emneord
- ionic liquid
- NMR
- rheology
- DFT calculations
- synthesis
- proton transfer