Ion-reagent interactions contributing to ionic liquid solvent effects on a condensation reaction

Sinead T. Keaveney*, Jason B. Harper, Anna K. Croft

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    8 Citations (Scopus)

    Abstract

    Molecular dynamics simulations of solutions of hexan-1-amine or 4-methoxybenzaldehyde in acetonitrile, an ionic liquid/acetonitrile mixture (χIL=0.2), and a number of different (neat) ionic liquids were performed, to further understand the solvent effects on the condensation reaction of these species. This work indicates that, in the presence of an ionic liquid, the amine group of hexan-1-amine is exclusively solvated by the components of the ionic liquid, and not by acetonitrile, and that the anion interacts with the aldehyde group of 4-methoxybenzaldehyde. These interactions showed little dependence on the proportion of the ionic liquid present. When varying the cation of the ionic liquid there were changes in the cation–amine interaction, and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ([Bm2im][N(CF3SO2)2]) was found to order more than expected about the amine. This ordering is likely the origin of the large rate constant values determined in [Bm2im][N(CF3SO2)2] for this condensation reaction and explains an anomaly seen previously. When changing the anion, changes were seen in the interactions between both the cation and anion with hexan-1-amine, and the anion with 4-methoxybenzaldehyde. The differing magnitude of these interactions likely causes subtle changes in the activation parameters for this condensation reaction, and provides an explanation for the anomalous rate constant values previously determined when varying the anion.

    Original languageEnglish
    Pages (from-to)3279-3287
    Number of pages9
    JournalChemPhysChem
    Volume19
    Issue number23
    Early online date5 Oct 2018
    DOIs
    Publication statusPublished - 5 Dec 2018

    Keywords

    • interactions
    • ionic liquids
    • molecular dynamics
    • ordering
    • solvent effects

    Fingerprint

    Dive into the research topics of 'Ion-reagent interactions contributing to ionic liquid solvent effects on a condensation reaction'. Together they form a unique fingerprint.

    Cite this