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This study focuses on the synthesis of a class of novel biologically-inspired ionic liquids coupled with a phosphonate group containing short to long side chains (C3–C11) via the Pudovic reaction. The ionic liquids exhibited very low glass transition temperatures and were hydrophobic in character. This method has the attributes of “click” chemistry with outstanding efficiency, simplicity, yields and regioselectivity. The results of their calcium(II) ligating capability are also presented.

ILs of dications with linked protic and aprotic centres have been prepared. They have rich H-bonding and a Bronsted acid–base character like small ΔpKa protic ILs, but very low apparent vapour pressures, more akin to aprotic ILs.

A wide variety of oximes were prepared from different types of alcohols with hydroxylamine hydrochloride using 1-methylimidaziloum nitrate, [Hmim][NO3], ionic liquid as a reaction medium and promoter under microwave irradiation. This protocol provides a one-pot oxime synthesis with high yields that is facile, eco-friendly and the ionic liquid can be recovered and reused.

A series of novel lipid-inspired ionic liquids have been synthesized employing the thiol-ene "click" reaction in a single-step process. The thermal properties were determined by differential scanning calorimetry (DSC) and showed observable trends between the C16, C18, and C20 analogues. The minimum melting points for each equivalent chain length series occur at sequential odd sulfur positions, 3, 5, and 7 for the C16, C18, and C20 series, respectively. The magnitude of melting point depression relative to the saturated homologue is observed to have a strong dependence on the position of the sulfur in the side chain. Additionally, the sulfur position corresponding to the lowest melting point for a homologous series shifts further down the chain as the chain length is increased, indicating that the maximum effect takes place near the center of the ion and not the center of the thiaalkyl chain. This synthesis provides tunability and improved thermal stability for 1-methyl-3-thiaalkylimidazolium bistriflimides and insight into structure-property relationships of lipidic ionic liquids.

In a head-to-head study, ILs based upon tetraarylphosphonium cations exhibit superior long-term thermal stability compared to familiar salts based upon imidazolium, quaternary ammonium, or tetraalkylphosphonium cations.

A simple approach for the preparation of symmetrical quaternary ammonium bromides employing thiol–ene click chemistry is used to synthesize tetra(4-thiaalkyl)ammonium bromides. This approach allows the incorporation of a variety of alkyl moieties onto the nitrogen center with a one-step synthesis involving easy work-up, no side reactions and environmentally friendly reagents. To elucidate information regarding the behaviour of this novel class of compounds, comparisons to tetraalkylammonium analogues have been made. These include melting points, activity as phase-transfer catalysts, and conformational predictions from computational modelling. All results are consistent in indicating stronger bonding between the quaternary cation and the anion for the salts with 4-thiaalkyl chains as compared to those with n-alkyl chains.