Does the method of combining individual components affect the structure of heteroconjugated oligomeric ionic liquids?

In this study, we proved that the structure of heteroconjugated oligomeric ionic liquids (HOILs) depends on the specific properties of the constituents rather than the preparation method used. To establish this fact, 6 functional HOILs were obtained with a natural (choline), natural-derived (decyl betainate) and fully synthetic (didecyldimethylammonium) cation, as well as oligomeric anions derived from the popular herbicides (MCPA and dicamba). Based on the results of spectral analysis (1H NMR, 13C NMR, FT-IR) of the HOILs obtained, it was possible to confirm that neither the cation structure, nor the chosen synthetic route has any effect on the definitive structure of the obtained systems, as MCPA occurred in the protonated form in all the HOILs studied. This result was further confirmed by the analysis of molecular geometry as well as the physicochemical properties (phase transition temperatures, refractive index) of the HOILs obtained. Therefore, the data acquired provide important guidance for the design of novel active ingredients according to the oligomeric IL concept and the development of methods for their efficient preparation.