Abobakr K. Ziyada

Effect of sulfonate-based anions on the physicochemical properties of 1-alkyl-3-propanenitrile imidazolium ionic liquids

In this paper, the physicochemical properties of a new series of ionic liquids (ILs) based on nitrile-functionalised imidazolium cations ([C2CN Cnim]+) with sulfonate-based anions were studied. The ILs were prepared by reacting imidazole with acrylonitrile, followed by butyl- and decyl bromide. The anions of the resulting bromide salts exchanged by metathesis to dioctylsulfosuccinate (DOSS), dodecylsulfate (DDS), benzenesulfonate (BS) and trifluoromethanesulfonate (TFMS). The densities of these ILs are lower compared to the those of other reported nitrile-functionalised ILs, while on the other hand, the viscosities of the ILs are higher due to the effects of the large anions and the long alkyl chain of the cations.

Densities, viscosities and refractive indices of 1-alkyl-3-propanenitrile imidazolium chloride ionic liquids

In this study, a series of nitrile-functionalised imidazolium ionic liquids ([C2CN Rim]Cl, where R = butyl, hexyl and octyl) were synthesised by reacting imidazole with acrylonitrile and then with butyl, hexyl and octyl chlorides, respectively. The structure of these compounds were established using 1H NMR, FT-IR and elemental analyses. The densities and viscosities were measured at T = (293.15–353.15 K), whereas the refractive index was measured at T = (293.15–333.15 K) and empirical correlations were proposed to represent this study. The decomposition temperatures were determined using a thermogravimetric analyser. The thermal expansion coefficients were also calculated and reported.

Synthesis and characterisations of Aliquat 336® and cetylpyridinium ionic liquids incorporated with sulfonate-based anions

A novel series of ionic liquids based on the tricaprylmethylammonium cation [C25H54N+], in Aliquat 336® and cetylpyridinium cation [C21H38N+] in cetylpyridinium chloride incorporating sulfonate-based anions were elegantly prepared by means of ion exchange between the Cl− cation with two different anions, namely, dioctylsulfosuccinate [DOSS−] and dihexylsulfosuccinate [HOSS−]. These ionic liquids were characterised using FTIR-ATR and NMR in order to identify the molecular structures of these compounds. The physical properties of these compounds, namely refractive index and thermal properties were measured at room temperature and are reported herein. ILs incorporating cetylpyridinium cations show higher thermal stability and refractive index values as compared to Aliquat ILs due to the effects of the aromatic ring on the cetylpyridinium cation as well as the longer alkyl chain on the anion of DOSS.