“…An increase in the alkyl chain length of the cation and the degree of branching weakened the interaction between the ions in the trifluoroacetate-containing PILs with dimethylethyl, triethyl, tributyl, and diisopropylethylammonium cations . Depending on the cation and anion, the hydrogen bonds in primary alkylammonium-based PILs differ from each other covering the full range from strong, short, and linear to weak, long, and bent types. ,, An extensive study of ethylammonium nitrate (one of the earliest PILs) was performed to understand its fundamental properties. ,− It was shown that hydrogen bonding between the ethylammonium cation and the nitrate anion leads to the formation of a three-dimensional network structure, akin to water. , The same holds for propyl- and butylammonium nitrate and their solutions in acetonitrile, isopropanol, and methanol . An extensive hydrogen bonding network in primary alkylammonium-based PILs with bis(trifluoromethanesulfonyl)amide leads to lower thermal stability and lower ionicity compared to their secondary and tertiary analogues .…”